CN113354811B - Oxazoline polymer with side chain containing amino and/or hydroxyl, preparation method and application thereof - Google Patents

Abstract

The invention relates to an oxazoline polymer with an amino group and/or hydroxyl group in a side chain, a preparation method and application thereof. The oxazoline polymer with the side chain containing the amino group can be used in the fields of antibacterial, antifungal, antiviral, anti-mite, antitumor, cell adhesion, tissue engineering, drug modification, protein protection, drug synergy, drug delivery, gene delivery, self-assembly materials and the like; the oxazoline polymer with the side chain containing hydroxyl can be used in the fields of surface antifouling, protein modification and protection, cell protection, tissue and organ freeze protection, drug modification and the like; the oxazoline polymer with the side chain containing the amino group and the hydroxyl group has the functions of the oxazoline polymer with the side chain containing the amino group and the hydroxyl group.

Description

An oxazoline polymer having amino and/or hydroxyl groups in the side chain, and its preparation method and application

Technical Field

The invention belongs to the technical field of polymers, and in particular relates to an oxazoline polymer having an amino group and/or a hydroxyl group in a side chain, and a preparation method and application thereof.

Background Art

Peptide polymers have similar secondary structures and biocompatibility to natural proteins, and thus show broad application prospects in the field of biomedical materials, such as protein mimicry, antibacterial materials, drug and gene delivery, stimulus-responsive peptides, tissue engineering, etc. However, since peptide polymers are easily degraded by proteases and lose their original functions, the study of protease-resistant peptide mimics is of great significance. Since the discovery of 2-substituted oxazoline polymers in the 1960s, they have been widely studied as a material that mimics the functions of PEG due to their good biocompatibility in many fields, such as thermoresponsive materials, antifouling materials, drug delivery, nano-drug delivery, and drug-protein coupling.

Although poly-2-methyloxazoline and poly-2-ethyloxazoline and derived materials thereof have been reported, only seldom literature reports the synthesis of amino-containing oxazoline polymers of side chains and very limited functions thereof in biomedical fields, for example, never document discloses that this type of polymer itself can have functions such as antibacterial function and antitumor. One of them important reason is that the conditions of oxazoline monomer polymerization are mainly as follows under normal circumstances: using methyl tosyl esters, methyl trifluoromethanesulfonate as initiator, using acetonitrile as solvent to carry out polyreaction. And Rainer Jordan subject group reported in 2006 that under normal conditions, can not successfully prepare the oxazoline polymers of amino-containing side chains, (Macromol Chem Phys 2006, 207 (2): 183-192.). In addition, the polymer that side chains contain hydroxyl has shown important functions in numerous research fields.

Therefore, there is an urgent need in the art to develop oxazoline polymers with amino groups in the side chains that have functions and application values in the biomedical field.

Summary of the invention

The purpose of the present invention is to provide an oxazoline polymer having an amino group and/or a hydroxyl group in the side chain, a preparation method thereof and application in the field of biomedical materials.

In a first aspect of the present invention, an oxazoline polymer is provided, comprising one or more repeating units represented by formula _E1 and/or formula _E2 .

wherein L ₁ and L' ₁ are each independently a bond, -CHR ₁ -, -CO-, -COO-, or -S(=O) ₂ -;

Each R ₁ and R ' ₁ is independently selected from the following group which is substituted or unsubstituted: H, amino, C1-C15 alkyl, C1-C15 alkylamino, C6-C15 aryl, C2-C15 alkenyl, C2-C15 alkynyl, C1-C15 alkylhydroxyl, C1-C15 alkylaldehyde, C1-C15 alkylester, thio-C1-C15 alkylester, -Rc-COO-Rc", -Rc-CO-Rc", -Rc-O-Rc"-, -Rc-S-Rc", 5-15 membered heteroaryl, 5-12 membered heterocyclyl;

_Ra and _Rb are each independently selected from the following substituted or unsubstituted groups: hydrogen, C1-C15 alkyl, C1-C15 alkylamino, C2-C15 alkenyl, C2-C15 alkynyl, C1-C15 alkylhydroxyl, C1-C15 alkylaldehyde, _C1 - _C15 alkylsulfonyl, -Rc-COO-Rc", -Rc-CO-Rc", -Rc-O-Rc"-, -Rc-S-Rc", C3-C12 cycloalkyl, C4-C12 cycloalkenyl, 5-12 membered heterocyclyl, C6-C12 aryl, 5-12 membered heteroaryl;

Or in formula E1, Ra together with O and its adjacent C atom forms a substituted or unsubstituted 3-12 membered heterocyclic group containing at least 1 O heteroatom and 0-2 heteroatoms selected from N and S;

Or in formula E2, _Ra and _Rb together with the adjacent N atom form a substituted or unsubstituted 3-12 membered heterocyclic group; or Ra together with N and its adjacent C atom form a substituted or unsubstituted 3-12 membered heterocyclic group containing at least 1 N heteroatom and 0-2 heteroatoms selected from O and S;

Rc is independently selected from the following substituted or unsubstituted groups: none, C1-C15 alkylene, C2-C15 alkenylene, C2-C15 alkynylene, C3-C12 cycloalkylene, C4-C12 cycloalkenylene, 3-12 membered heterocyclylene, C6-C12 arylene, 5-12 membered heteroarylene;

Rc" is independently selected from the following substituted or unsubstituted groups: C1-C15 alkyl, C1-C15 alkylamino, C2-C15 alkenyl, C2-C15 alkynyl, C3-C12 cycloalkyl, C4-C12 cycloalkenyl, 3-12 membered heterocyclyl, C6-C12 aryl, 5-12 membered heteroaryl;

m is 1, 2, 3, or 4;

m' is 1, 2, 3, or 4;

q is an integer of 0, 1, 2, 3, 4, or 5;

q' is an integer of 0, 1, 2, or 3; and m'+q'≤4;

The substitution refers to substitution by one or more groups selected from the following groups: halogen, hydroxyl, amino, guanidino, -CO- _NH2 , -COOH, -SH, C1-C6 alkyl S-, Ph-, -PhOH, glucosyl, C1-C15 alkyl, C1-C15 haloalkyl, C1-C15 alkoxy, C1-C15 haloalkoxy, C3-C15 cycloalkyl, C4-C12 cycloalkenyl, 5-10 membered heteroaryl, 5-12 membered heterocyclyl.

In another preferred embodiment, Rc" is methyl.

In another preferred embodiment, R ₁ and R' ₁ are each independently a substituted or unsubstituted C1-C3 alkylamino group, preferably a methylamino group.

In another preferred embodiment, the polymer is a copolymer.

In another preferred embodiment, the polymer is a homopolymer.

In another preferred embodiment, the polymer is polymerized using an initiator selected from the group consisting of methyl trifluoromethylsulfonate, trifluoromethylbenzoyl, and substituted or unsubstituted C1-C15 halogenated alkanes.

In another preferred embodiment, when the polymer is a homopolymer composed of repeating units represented by formula E2, each R ₁ ′ is H, L ₁ ′ is CH ₂ , and m′+q′=4, Ra and Rb are not H at the same time.

In another preferred embodiment, L ₁ and L' ₁ are each independently -CH ₂ -.

In another preferred embodiment, the amino or guanidinium functional group in the oxazoline polymer structure is in the form of hydrochloride, hydrobromide, formate, acetate, or trifluoroacetate.

In another preferred embodiment, the amino group in the oxazoline polymer structure is converted into a guanidine functional group.

In another preferred embodiment, the oxazoline polymer structure is a ternary, quaternary or higher random or block copolymer.

In another preferred embodiment, the terminal of the oxazoline polymer structure is converted into other functional groups such as hydroxyl, amino, ester, etc.

In another preferred embodiment, after the terminal of the oxazoline polymer structure is converted into other functional groups such as hydroxyl, amino, ester, etc., it is further modified with other active molecules such as dye molecules and drug molecules to obtain terminal functionalized oxazoline polymers.

In another preferred embodiment, _Ra and _Rb are each independently H, benzyl, tert-butyloxycarbonyl, benzyloxycarbonyl, tert-butyl, trityl, or fluorenylmethoxycarbonyl; or _Ra and _Rb together with their adjacent N atoms form a succinimide-containing group.

In another preferred embodiment, the structure of the group containing succinimide is selected from the following group: in Represents a single bond or a double bond, Ar is a substituted or unsubstituted 5-12 membered heteroaryl or a substituted or unsubstituted C6-C12 aryl, wherein the substitution refers to substitution by one or more groups selected from the following groups: C1-C6 alkyl, C1-C6 alkoxy, C3-C8 cycloalkyl, C4-C8 cycloalkenyl, 5-10 membered heteroaryl, 5-12 membered heterocyclyl.

In another preferred embodiment, the formula _E2 has a structure shown in formula _E'2 :

in,

Ring A is independently a substituted or unsubstituted 3-12 membered heterocyclic group;

Wherein, the substitution refers to substitution by one or more groups selected from the group consisting of halogen, hydroxyl, amino, guanidino, -CO-NH ₂ , -COOH, -SH, C1-C6 alkyl S-, Ph-, -PhOH, glucosyl, C1-C15 alkyl, C1-C15 haloalkyl, C1-C15 alkoxy, C1-C15 haloalkoxy, C3-C15 cycloalkyl, C4-C12 cycloalkenyl, 5-10 membered heteroaryl, 5-12 membered heterocyclyl;

R' ₁ , m', and Rb are as defined above.

In another preferred embodiment, the oxazoline polymer is a homopolymer, which comprises a repeating unit represented by any one of Formula _E1 and Formula _E2 .

In another preferred embodiment, the oxazoline polymer is a copolymer, which comprises a plurality of repeating units represented by Formula _E1 or Formula _E2 .

In another preferred embodiment, the average molecular weight of the oxazoline polymer is in the range of 500-100000, preferably 1000-10000, and more preferably 2000-4000.

In another preferred embodiment, the PDI of the oxazoline polymer is in the range of 1.01-1.5.

In another preferred embodiment, both ends of the oxazoline polymer are modified with functional groups or active molecules.

In another preferred embodiment, the side chain of the oxazoline polymer is modified with a functional group or an active molecule.

In another preferred embodiment, the side chain of the oxazoline polymer acts as an initiator to initiate polymerization of other monomers to obtain an oxazoline polymer brush.

In another preferred embodiment, the side chain amino group of the oxazoline polymer is used as an initiator, and the other initiated monomers are selected from the following groups: α-NCA, α-NTA, β-NCA, β-NTA, γ-NCA, γ-NTA; α-NNCA, α-NNTA, β-NNCA, β-NNTA, γ-NNCA, γ-NNTA (the NCA described here is an N-carboxyl ring anhydride monomer, NNCA is an N-substituted N-carboxyl ring anhydride monomer, NTA is an N-carboxylthiocarbonyl ring anhydride monomer, and NNTA is an N-substituted N-carboxylthiocarbonyl ring anhydride monomer, wherein α-, β-, and γ- refer to α-amino acid, β-amino acid, and γ-amino acid, respectively).

In another preferred embodiment, the other monomers are one or more compounds represented by formula D, E, and F:

_X2 ＝O or S

In the formula, _X2 is O or S; _R11 and _R22 can be independently selected from any substituted functional group.

In another preferred embodiment, the oxazoline polymer further comprises one or more of the repeating units B and/or C:

in,

_R2 is independently selected from the following groups: substituted or unsubstituted: C1-C8 alkyl, C3-C8 cycloalkyl, C6-C12 aryl, C6-C12 arylalkyl, C2-C15 alkenyl, C4-C12 cycloalkenyl, C2-C15 alkynyl, C1-C15 alkylhydroxyl, C1-C15 alkylaldehyde, -Rc-COO-Rc", -Rc-CO-Rc", -Rc-O-Rc"-, -Rc-S-Rc", 5-12 membered heteroaryl, 5-12 membered heterocyclyl;

_Ra is independently selected from the following group: substituted or unsubstituted: hydrogen, C1-C15 alkyl, C6-C12 aryl, C2-C15 alkenyl, C2-C15 alkynyl, C3-C12 cycloalkyl, C4-C12 cycloalkenyl, 5-12 membered heteroaryl, 5-12 membered heterocyclyl _-CH2- ;

Rc is independently selected from the following substituted or unsubstituted groups: none, C1-C15 alkylene, C2-C15 alkenylene, C2-C15 alkynylene, C3-C12 cycloalkylene, C4-C12 cycloalkenylene, 3-12 membered heterocyclylene, C6-C12 arylene, 5-12 membered heteroarylene;

Rc" is independently selected from the following substituted or unsubstituted groups: C1-C15 alkyl, C1-C15 alkylamino, C2-C15 alkenyl, C2-C15 alkynyl, C3-C12 cycloalkyl, C4-C12 cycloalkenyl, 3-12 membered heterocyclyl, C6-C12 aryl, 5-12 membered heteroaryl;

Wherein, the substitution refers to substitution by one or more groups selected from the group consisting of halogen, hydroxyl, amino, guanidino, -CO-NH ₂ , -COOH, -SH, C1-C6 alkyl S-, Ph-, -PhOH, glucosyl, C1-C15 alkyl, C1-C15 haloalkyl, C1-C15 alkoxy, C1-C15 haloalkoxy, C3-C15 cycloalkyl, C4-C12 cycloalkenyl, 5-10 membered heteroaryl, 5-12 membered heterocyclyl;

L ₁ , R ₁ , m and q are as defined above.

In another preferred embodiment, when the oxazoline polymer is a binary copolymer having repeating units of formula _E2 and formula B, _R2 is not H, methyl or ethyl.

In another preferred embodiment, the oxazoline polymer does not contain the following repeating units:

Wherein, t is a positive integer ≥1.

In another preferred embodiment, the repeating unit of formula E ₁ , formula E ₂ , formula B or formula C can be optionally connected to another repeating unit of formula E ₁ , formula E ₂ , formula B or formula C.

In another preferred embodiment, the oxazoline polymer is an oxazoline polymer containing an amino group in the side chain, which has a structure as shown in Formula II:

Wherein, n is an integer of 5-50000; 0%<x<100%; 0%≤y<100%; 0%≤z<100% wherein x, y, and z are calculated by dividing the corresponding number of side chain repeating units by the total number of repeating units;

m, m', R ₁ , R' ₁ , R ₂ , _Ra and R _b are as defined above.

In another preferred embodiment, 10%≤x+y+z≤100%, more preferably 50%≤x+y+z≤100%.

In another preferred embodiment, 30%≤x≤90%.

In another preferred embodiment, 10%≤y<70%.

In another preferred embodiment, 10%≤z<70%.

In another preferred embodiment, n is 5-5000, preferably 20-1000.

In another preferred embodiment, the oxazoline polymer containing an amino group in the side chain has a structure as shown in Formula V:

wherein n, x, y, z, m, m', R ₁ , R' ₁ and R ₂ are as defined above.

In another preferred embodiment, the oxazoline polymer containing an amino group in the side chain has a structure as shown in Formula VII:

n, x, y, z, A, m, m', _R1 , _R'1 , _R2 and _Rb are as defined above.

In another preferred embodiment, the oxazoline polymer containing an amino group in the side chain has a structure as shown in Formula VIII:

R ₆ is independently substituted or unsubstituted C1-C15 alkyl-NRaRb, substituted or unsubstituted 5-12 membered heterocyclyl;

Wherein, the substitution refers to substitution by one or more groups selected from the group consisting of halogen, hydroxyl, amino, guanidinyl, -CO-NH ₂ , -COOH, -SH, C1-C6 alkyl S-, Ph-, -PhOH, 5-12 membered heteroaryl, 5-12 membered heterocyclyl;

n, x, y, z, m, _R1 and _R2 are as defined above.

In another preferred embodiment, the oxazoline polymer is an oxazoline polymer having a hydroxyl group in the side chain, which has a structure as shown in Formula I:

wherein m, R ₁ , R ₂ , and _Ra are defined as above; n is an integer of 5-50000; 0%<x<100%;0%≤y<100%;0%≤z<100%; wherein x, y, and z are calculated by dividing the corresponding number of side chain repeating units by the total number of repeating units.

In another preferred embodiment, the oxazoline polymer containing a hydroxyl group in the side chain has a structure as shown in IV:

wherein n, x, y, z, m, _R1 and _R2 are as defined above.

In another preferred embodiment, the oxazoline polymer is an oxazoline polymer having an amino group and a hydroxyl group in the side chain, and has a structure as shown in Formula III:

Wherein, 0%＜w<100%; 0%≤x ₁ <100%; wherein w, x ₁ , y, and z are calculated by dividing the corresponding number of repeating units by the total number of repeating units;;

m, m', _R1 , _R'1 , _R2 , _Ra , _Rb , n, y and z are as defined above.

In another preferred embodiment, 10%≤w≤90%.

In another preferred embodiment, 10%≤x ₁ ≤90%.

In another preferred embodiment, 10%≤w+x1+y+z≤100%, more preferably 50%≤w+x1+y+z≤100%.

In another preferred embodiment, the oxazoline polymer having an amino group and a hydroxyl group in the side chain has a structure as shown in Formula VI or Formula IX:

in,

m, m', n, x, y, z, w, _x1 , _R1 , _R'1 , _R2 and _R6 are as defined above.

In another preferred embodiment, _R6 is a part other than the carboxyl group in the molecular structure of a natural amino acid or a non-natural amino acid.

In another preferred embodiment, the natural amino acid is selected from the following group: glycine, alanine, valine, leucine, isoleucine, phenylalanine, tryptophan, tyrosine, aspartic acid, asparagine, glutamic acid, lysine, glutamine, methionine, serine, threonine, cysteine, proline, histidine, arginine, etc., and derivatives derived from the above amino acids.

In another preferred embodiment, the non-natural amino acids include β-amino acids, γ-amino acids, δ-amino acids, and ε-amino acids.

In another preferred embodiment, the non-natural amino acid includes D-type, L-type or DL-type.

In a second aspect, the present invention provides a method for preparing an oxazoline polymer having an amino group in a side chain, comprising the steps of:

In an organic solvent, in the presence of an initiator and under heating conditions, polymerizing an oxazoline monomer represented by formula _E'2 and optionally a monomer of formula B' and/or formula C' to obtain an oxazoline polymer containing an amino group in the side chain;

wherein R' ₁ , m', q', L ₁ ', R ₁ , m, q, L ₁ , _Ra and R _b are as defined above.

In another preferred embodiment, the oxazoline polymer containing amino groups in the side chain is an oxazoline homopolymer containing amino groups in the side chain or an oxazoline copolymer containing amino groups in the side chain.

In another preferred embodiment, the oxazoline polymer containing amino groups in the side chain is a block type oxazoline copolymer containing amino groups in the side chain or a blend type oxazoline copolymer containing amino groups in the side chain.

In another preferred embodiment, the method for preparing an oxazoline homopolymer containing an amino group in the side chain comprises the steps of: polymerizing an oxazoline monomer represented by formula _E'2 in an organic solvent in the presence of an initiator to obtain an oxazoline homopolymer containing an amino group in the side chain.

In another preferred embodiment, in the method for preparing an oxazoline polymer having an amino group in the side chain, the heating condition has a temperature range of 80°C to 140°C, preferably 120°C.

In another preferred embodiment, in the method for preparing an oxazoline polymer having an amino group in the side chain, the polymerization reaction time is 2 h to 8 h, preferably 6 h.

In another preferred embodiment, in the method for preparing the oxazoline polymer having an amino group in the side chain, the organic solvent is selected from the group consisting of DMAc, DMF, or a combination thereof; preferably DMAc.

In another preferred embodiment, in the method for preparing an oxazoline polymer having an amino group in the side chain, the initiator is selected from the group consisting of MeOTf, BzOTf, or a combination thereof.

In another preferred embodiment, the oxazoline polymer containing amino groups in the side chain of the present invention is prepared by the following method: in an organic solvent and under the protection of an inert gas, in the presence of an initiator and under heating conditions, an oxazoline monomer represented by formula _E'2 and optionally a monomer of formula B' and/or formula C' are polymerized to obtain an oxazoline polymer containing amino groups in the side chain.

In another preferred embodiment, the preparation method of the oxazoline polymer containing an amino group on the side chain needs to be carried out under the protection of an inert gas.

In another preferred embodiment, in the method for preparing an oxazoline polymer having an amino group in the side chain, the inert gas is _N2 or Ar.

In another embodiment, the oxazoline monomer of formula _E'2 has a structure as shown in formula E" ₂ :

In the formula,

R ₇ is independently selected from the following substituted or unsubstituted groups: hydrogen, C1-C15 alkyl, C1-C15 alkylamino, C2-C15 alkenyl, C2-C15 alkynyl, C1-C15 alkylhydroxyl, C1-C15 alkylaldehyde, -Rc-COO-Rc", -Rc-CO-Rc", -Rc-O-Rc"-, -Rc-S-Rc", C3-C12 cycloalkyl, C4-C12 cycloalkenyl, 5-12 membered heterocyclyl, C6-C12 aryl, 5-12 membered heteroaryl;

Rc is independently selected from the group consisting of substituted or unsubstituted groups: none, C1-C15 alkylene, C2-C15 alkenylene, C2-C15 alkynylene, C3-C12 cycloalkylene, C4-C12 cycloalkenylene, 3-12 membered heterocyclylene, C6-C12 arylene, 5-12 membered heteroarylene;

Rc" is independently selected from the following substituted or unsubstituted groups: C1-C15 alkyl, C1-C15 alkylamino, C2-C15 alkenyl, C2-C15 alkynyl, C3-C12 cycloalkyl, C4-C12 cycloalkenyl, 3-12 membered heterocyclyl, C6-C12 aryl, 5-12 membered heteroaryl;

_P1 is an amino protecting group selected from the group consisting of tert-butyloxycarbonyl (Boc), benzyloxycarbonyl (Cbz), fluorenylmethyloxycarbonyl (Fmoc), phthaloyl (Pht), acetyl (Ac), trifluoroacetyl (Tfa), benzyl (Bn), triphenylmethyl (Tr), or _R7 and _P1 together with their adjacent N atoms form a succinimide-containing group;

Wherein, the substitution refers to substitution by one or more groups selected from the group consisting of halogen, hydroxyl, amino, guanidino, -CO-NH ₂ , -COOH, -SH, C1-C6 alkyl S-, Ph-, -PhOH, glucosyl, C1-C15 alkyl, C1-C15 haloalkyl, C1-C15 alkoxy, C1-C15 haloalkoxy, C3-C15 cycloalkyl, C4-C12 cycloalkenyl, 5-10 membered heteroaryl, 5-12 membered heterocyclyl;

m' and R' ₁ are as defined above, and -(CHR' ₁ ) _m' - is not -(CH ₂ ) ₄ .

In another preferred embodiment, one or more oxazoline monomers represented by formula E" ₂ are polymerized in an organic solvent in the presence of an initiator to obtain an oxazoline polymer having an amino protecting group in the side chain; after removing the protected amino group, an oxazoline polymer having an amino group in the side chain is obtained; optionally, the amino group in the oxazoline polymer having an amino group in the side chain is functionalized to a guanidine group to obtain an oxazoline polymer having a guanidine group in the side chain.

In another preferred embodiment, the method for preparing the oxazoline copolymer containing amino groups in the side chain comprises the steps of:

(i) in an organic solvent, in the presence of an initiator and under heating conditions, firstly subjecting an oxazoline monomer having a structure of formula _E'2 to a polymerization reaction,

(ii) After the polymerization reaction in step (i) is completed, another monomer having the formula E' ₂ , the formula B' or the formula C' is added to carry out a polymerization reaction.

and optionally (iii) repeating step (ii) f times, thereby forming a block type side chain-containing aminooxazoline copolymer;

or (i') in an organic solvent, an oxazoline monomer having a structure of formula _E'2 is mixed with one or more monomers of another formula _E'2 , formula B' or formula C', and (ii') polymerized in the presence of an initiator and under heating conditions to form a blended oxazoline copolymer containing amino groups in the side chain;

Here, f is an integer ≥1.

In a third aspect of the present invention, there is provided an oxazoline monomer having a hydroxyl group in the side chain, having a structure as shown in Formula _E'1 :

Here, R ₁ , m, q, L ₁ , and Ra are as defined above.

In another preferred embodiment, formula _E'1 has a structure as shown in formula E" ₁ :

Wherein, _P2 is a hydroxyl protecting group, preferably TMS, TBS, TBDPS, t-Bu; m, _R1 are as defined above;

In another preferred embodiment, a method for synthesizing an oxazoline monomer represented by E" ₁ is provided, and the specific steps include:

Wherein, m, P ₂ , and R ₁ are as defined above;

X is a leaving group;

(2) In a second inert solvent, compound 2 is reacted with a base to obtain a monomer of formula E″ ₁ .

In another preferred embodiment, the base is an organic base, an inorganic base, or a combination thereof.

In another preferred embodiment, the base is selected from the following group: sodium hydroxide, potassium hydroxide, triethylamine, N,N-diisopropylethylamine, or a combination thereof.

In another preferred embodiment, the second inert solvent is independently selected from the following group: methanol, ethanol, acetonitrile, or a combination thereof.

In another preferred embodiment, the leaving group is selected from the following group: Br, Cl, I, OTs, OMs.

In another preferred embodiment, the method for preparing the monomer of formula E" ₁ further comprises the steps of:

In the formula,

R ₁ , P ₂ , X, and m are as defined above;

(1) Compound 1 is reacted with H ₂ N(CH ₂ ) ₂ X in a first inert solvent to obtain compound 2.

In another preferred embodiment, in step (1), the reaction temperature is 0-70°C; preferably, 0-25°C.

In another preferred embodiment, in the step (1), the reaction time is 6 hours to 1 day.

In another preferred embodiment, in step (1), H ₂ N(CH ₂ ) ₂ X is in the form of its hydrochloride or hydrobromide.

In another preferred embodiment, the step (1) is to dissolve compound 1 and DIEA in a first inert solvent, add Et ₃ N, EDCI and HOBT in an ice bath, stir and react for 30 minutes, then add H ₂ N(CH ₂ ) ₂ X; after reacting at room temperature for 8 hours, wash the reaction mixture twice with deionized water and 5% citric acid aqueous solution, respectively, and after drying and concentrating the organic phase, separate and purify by column to obtain compound 2.

In another preferred embodiment, in the step (1), the first inert solvent is independently selected from the following group: DCM, DMF, THF, DMAc, or a combination thereof; preferably DCM.

In another preferred embodiment, the step (2) is to dissolve the compound 2 obtained in (1) in a second inert solvent, add a base to react at 70° C. under the protection of an inert gas; after the reaction is completed, remove the solvent, add dichloromethane to dissolve, and wash twice with deionized water, dry and concentrate the organic phase, and then purify it by reduced pressure distillation to obtain a monomer of formula E” ₁ .

In another preferred embodiment, in the step (2), the second inert solvent is dry.

In a fourth aspect, the present invention provides a method for preparing an oxazoline polymer having a hydroxyl group in a side chain, which specifically comprises the following steps:

In an inert solvent and under inert gas protection, in the presence of an initiator and under heating conditions, an oxazoline monomer represented by formula _E'1 and optionally a monomer of formula B' and/or formula C' are polymerized to obtain an oxazoline polymer having side chain hydroxyl groups;

wherein R ₁ , m, q, L ₁ , _Ra and R ₂ are as defined above.

In another preferred embodiment, the oxazoline polymer having hydroxyl groups on the side chains is an oxazoline homopolymer having hydroxyl groups on the side chains or an oxazoline copolymer having hydroxyl groups on the side chains.

In another preferred embodiment, the oxazoline polymer containing hydroxyl groups on the side chains is a block type oxazoline copolymer containing hydroxyl groups on the side chains or a blend type oxazoline copolymer containing hydroxyl groups on the side chains.

In another preferred embodiment, the method for preparing an oxazoline homopolymer containing hydroxyl groups in the side chain comprises the steps of: in an inert solvent and under inert gas protection, in the presence of an initiator and under heating conditions, polymerizing an oxazoline monomer represented by formula _E'1 to obtain an oxazoline homopolymer containing hydroxyl groups in the side chain.

In another preferred embodiment, in the method for preparing the oxazoline polymer having a hydroxyl group on the side chain, the inert solvent is selected from the group consisting of DMAc, DMF, MeCN, PhCN, or a combination thereof.

In another preferred embodiment, in the method for preparing the oxazoline polymer having a hydroxyl group on the side chain, the inert gas is selected from the following group: N ₂ , Ar, or a combination thereof.

In another preferred embodiment, in the method for preparing the oxazoline polymer having a hydroxyl group in the side chain, the initiator is selected from the group consisting of MeOTf, BzOTf, CH ₃ (CH ₂ ) ₅ Br, CH ₃ (CH ₂ ) ₅ OTs, or a combination thereof.

In another preferred embodiment, the method for preparing the oxazoline copolymer containing hydroxyl groups in the side chain comprises the steps of:

(a) in an inert solvent and inert gas protection, in the presence of an initiator and under heating conditions, firstly subjecting an oxazoline monomer having a structure of formula _E'1 to a polymerization reaction,

(b) After the polymerization reaction in step (a) is completed, another monomer having the formula _E'1 , formula B' or formula C' is added to carry out a polymerization reaction.

and optionally (c) repeating step (b) f times, thereby forming a block type oxazoline copolymer containing hydroxyl groups in the side chains;

or (a') in an inert solvent and under inert gas protection, an oxazoline monomer having a structure of formula _E'1 is mixed with one or more monomers of formula _E'1 , formula B' or formula C', and (b') in the presence of an initiator and under heating conditions, a polymerization reaction is carried out to form a blended oxazoline copolymer containing amino groups in the side chain;

f is an integer ≥1.

In another preferred embodiment, in the method for preparing the oxazoline polymer containing hydroxyl groups in the side chain, the temperature range of the heating condition is 80°C-140°C; preferably 80°C-120°C.

In another preferred embodiment, in the method for preparing an oxazoline polymer having a hydroxyl group in the side chain, the polymerization reaction time is 2 h-8 h, preferably 6 h.

A fifth aspect of the present invention provides a method for preparing an oxazoline polymer having an amino group and a hydroxyl group in a side chain, which specifically comprises the following steps:

In an organic solvent, in the presence of an initiator and under heating conditions, an oxazoline monomer represented by formula _E'2 and an oxazoline monomer represented by formula _E'1 , and optionally oxazoline monomers of other structures, are subjected to polymerization reaction to obtain an oxazoline polymer having an amino group and a hydroxyl group in the side chain;

wherein R' ₁ , m', q', L ₁ ', R ₁ , m, q, L ₁ , _Ra and R _b are as defined above.

In another preferred embodiment, the oxazoline monomer with other structures is optionally a monomer of formula B' or formula C',

wherein R ₁ , R ₂ , m, q, L ₁ , and _Ra are as defined above.

In another preferred embodiment, the oxazoline polymer having amino and hydroxyl groups in the side chain is a block type oxazoline copolymer having amino groups in the side chain or a blend type oxazoline copolymer having amino groups in the side chain.

In another preferred embodiment, in the method for preparing an oxazoline polymer having amino and hydroxyl groups in the side chain, the heating condition has a temperature range of 80°C-140°C, preferably 120°C.

In another preferred embodiment, in the method for preparing an oxazoline polymer having amino and hydroxyl groups in its side chain, the polymerization reaction time is 2 h to 36 h, preferably 6 h.

In another preferred embodiment, in the method for preparing the oxazoline polymer having amino and hydroxyl groups in the side chain, the organic solvent is selected from the group consisting of DMAc, DMF, or a combination thereof; preferably DMAc.

In another preferred embodiment, in the method for preparing the oxazoline polymer having amino and hydroxyl groups in the side chain, the initiator is selected from the group consisting of MeOTf, BzOTf, or a combination thereof.

In another preferred embodiment, the preparation method of the oxazoline polymer having amino and hydroxyl groups in the side chain needs to be carried out under the protection of an inert gas.

In another preferred embodiment, in the method for preparing the oxazoline polymer having amino and hydroxyl groups in the side chain, the inert gas is N ₂ , Ar, or a combination thereof.

In another preferred embodiment, one or more oxazoline monomers represented by formula E" ₂ and one or more oxazoline monomers represented by E" ₁ are polymerized in an organic solvent in the presence of an initiator and under heating conditions to obtain an oxazoline polymer having amino-protected and hydroxyl-protected side chains; after removing the protecting groups, an oxazoline polymer having amino and hydroxyl side chains is obtained; optionally, the amino groups in the obtained oxazoline polymer having amino and hydroxyl groups are functionalized to guanidine groups to obtain an oxazoline polymer having guanidine and hydroxyl side chains.

In another preferred embodiment, the oxazoline polymer having amino and hydroxyl groups in the side chain is a block type oxazoline copolymer having amino and hydroxyl groups in the side chain or a blend type oxazoline copolymer having amino and hydroxyl groups in the side chain.

In another preferred embodiment, the method for preparing the oxazoline copolymer containing amino and hydroxyl groups in the side chain comprises the steps of:

(d) firstly subjecting an oxazoline monomer having a structure of formula _E'2 to polymerization reaction in an organic solvent in the presence of an initiator and under heating conditions,

(dd) After the polymerization reaction in step (d) is completed, another monomer having the formula _E'1 is added to carry out a polymerization reaction.

(ddd) After the polymerization reaction in step (dd) is completed, another monomer having formula B' or formula C' is added to carry out polymerization reaction.

and optionally (dddd) repeating step (d), (dd) or (ddd) f times, thereby forming a block type oxazoline copolymer containing amino groups and hydroxyl groups in the side chains;

or (d') in an organic solvent, mixing oxazoline monomers having structures of formula _E'2 and formula _E'1 with one or more monomers of formula _E'2 , formula _E'1 , formula B' or formula C', and (ii') polymerizing them in the presence of an initiator and under heating conditions to form a blended oxazoline copolymer containing amino and hydroxyl groups in the side chains;

Here, f is an integer ≥1.

In a sixth aspect, the present invention provides a use of an oxazoline polymer having an amino group in a side chain for preparing materials for antibacterial, antitumor, cell adhesion, tissue engineering, drug and gene delivery, drug modification, cell adhesion or self-assembly.

In another preferred embodiment, the antibacterial material is in the form of a solution or a surface coating.

In another preferred embodiment, the antibacterial target is microorganisms such as bacteria and fungi, which may include Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa), Acinetobacter baumannii (A. baumannii), Enterobacter aerogenes (E. aerogenes), Klebsiella pneumoniae (K. pneumoniae), Serratia marcescens (S. marcescens), Enterobacter cloacae (E. cloacae), Bacillus subtilis (B. subtilis), Staphylococcus aureus (S. aureus), Staphylococcus epidermidis (S. epidermidis), Candida albicans (C. albicans), and Cryptococcus neoformans (C. neoformans).

In another preferred embodiment, the antibacterial use includes free cells, biofilms, spores and other forms of microorganisms.

In another preferred embodiment, the polymer is used for drug synergistic antibacterial effect.

In another preferred embodiment, the polymer is used for treating tumors.

In another preferred embodiment, the tumor is selected from the following group: melanoma, skin cancer, glioma, mesothelioma, lymphoma, leukemia, breast cancer, ovarian cancer, cervical cancer, glioblastoma, multiple myeloma, prostate cancer, Burkitt's lymphoma, head and neck cancer, colon cancer, colorectal cancer, non-small cell lung cancer, small cell lung cancer, esophageal cancer, gastric cancer, pancreatic cancer, hepatobiliary cancer, gallbladder cancer, small intestine cancer, rectal cancer, kidney cancer, bladder cancer, prostate cancer, penile cancer, urethral cancer, testicular cancer, vaginal cancer, uterine cancer, thyroid cancer, parathyroid cancer, adrenal cancer, pancreatic endocrine cancer, carcinoid, bone cancer, retinoblastoma, Hodgkin's lymphoma, non-Hodgkin's lymphoma, Kaposi's sarcoma, multicentric Castleman's disease, AIDS-related primary effusion lymphoma, neuroectodermal tumor or rhabdomyosarcoma.

In a seventh aspect, the present invention provides an application of an oxazoline polymer having a hydroxyl group in a side chain, which is used in biomedical fields such as surface antifouling, cell cryopreservation, and drug modification.

In another preferred embodiment, the oxazoline polymer having side chain hydroxyl groups is used for surface antifouling coating.

In another preferred embodiment, the surface antifouling object is the adhesion of bacteria, and the bacteria include Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa), Acinetobacter baumannii (A. baumannii), Enterobacter aerogenes (E. aerogenes), Klebsiella pneumoniae (K. pneumoniae), Serratia marcescens (S. marcescens), Enterobacter cloacae (E. cloacae), Bacillus subtilis (B. subtilis), Staphylococcus aureus (S. aureus), Staphylococcus epidermidis (S. epidermidis), Candida albicans (C. albicans), and Cryptococcus neoformans (C. neoformans).

In another preferred embodiment, the antifouling application includes adhesion to proteins.

In another preferred embodiment, the oxazoline polymer with side chain hydroxyl groups is used for cell cryopreservation.

In another preferred embodiment, the cells are selected from the following groups: mammalian embryonic stem cells, mammalian induced pluripotent stem cells, mammalian original pluripotent stem cells, cells differentiated from mammalian embryonic stem cells, mammalian induced pluripotent stem cells and mammalian initial pluripotent stem cells, mammalian cells reprogrammed from other cell types, mammalian primary cells, human umbilical vein endothelial cells, cancer cells, T cells, mammalian tissue stem cells, and mammalian cell lines.

In an eighth aspect, the present invention provides a use of an oxazoline polymer having amino and hydroxyl groups in the side chain, which can be used in biomedicine fields such as antibacterial, antitumor, tissue engineering, drug and gene delivery, drug modification, cell adhesion, self-assembled materials, surface antifouling, cell cryopreservation, and drug modification.

According to a ninth aspect of the present invention, there is provided a polymerization method, which comprises using the oxazoline polymer of the first aspect as an initiator to initiate a monomer.

In another preferred embodiment, in the polymerization method, the oxazoline polymer is a polymer having an amino group in the side chain.

In another preferred embodiment, in the polymerization method, the oxazoline polymer is a polymer having -NH ₂ in the side chain.

In another preferred embodiment, in the polymerization method, the oxazoline polymer has a structure as shown in Formula V:

wherein n, x, y, z, m, m', R ₁ , R' ₁ and R ₂ are as defined above.

In another preferred embodiment, in the polymerization method, the oxazoline polymer has a structure as shown in Formula VII:

n, x, y, z, A, m, m', _R1 , _R'1 , _R2 and _Rb are as defined above.

In another preferred embodiment, in the polymerization method, the oxazoline polymer has a structure as shown in Formula VIII:

R ₆ is independently substituted or unsubstituted C1-C15 alkyl-NRaRb, substituted or unsubstituted 5-12 membered heterocyclyl;

Wherein, the substitution refers to substitution by one or more groups selected from the group consisting of halogen, hydroxyl, amino, guanidinyl, -CO-NH ₂ , -COOH, -SH, C1-C6 alkyl S-, Ph-, -PhOH, 5-12 membered heteroaryl, 5-12 membered heterocyclyl;

n, x, y, z, m, _R1 and _R2 are as defined above.

In another preferred embodiment, in the polymerization method, the oxazoline polymer has a structure as shown in Formula I:

wherein m, R ₁ , R ₂ , and _Ra are defined as above; n is an integer of 5-50000; 0%<x<100%;0%≤y<100%;0%≤z<100%; wherein x, y, and z are calculated by dividing the corresponding number of side chain repeating units by the total number of repeating units.

In another preferred embodiment, in the polymerization method, the oxazoline polymer has a structure as shown in IV:

wherein n, x, y, z, m, _R1 and _R2 are as defined above.

In another preferred embodiment, in the polymerization method, the oxazoline polymer has a structure as shown in Formula VI or Formula IX:

in,

m, m', n, x, y, z, w, _x1 , _R1 , _R'1 , _R2 and _R6 are as defined above.

In another preferred embodiment, in the polymerization method, the side chain amino group of the oxazoline polymer is used as an initiator, and the other initiated monomers are selected from the following groups: α-NCA, α-NTA, β-NCA, β-NTA, γ-NCA, γ-NTA; α-NNCA, α-NNTA, β-NNCA, β-NNTA, γ-NNCA, γ-NNTA (the NCA described here is an N-carboxyl ring anhydride monomer, NNCA is an N-substituted N-carboxyl ring anhydride monomer, NTA is an N-carboxylthiocarbonyl ring anhydride monomer, NNTA is an N-substituted N-carboxylthiocarbonyl ring anhydride monomer, wherein α-, β-, and γ- refer to α-amino acid, β-amino acid, and γ-amino acid, respectively).

In another preferred embodiment, in the polymerization method, the other monomers are one or more compounds represented by formula D, E, and F:

_X2 ＝O or S

In the formula, _X2 is O or S; _R11 and _R22 can be independently selected from any substituted functional group.

It should be understood that within the scope of the present invention, the above-mentioned technical features of the present invention and the technical features specifically described below (such as embodiments) can be combined with each other to form a new or preferred technical solution. Due to space limitations, they will not be described one by one here.

DETAILED DESCRIPTION

After long-term and in-depth research, the inventor unexpectedly found that the repeating unit oxazoline polymer containing formula _E1 and/or formula _E2 can be widely used in biomedical fields such as antibacterial, drug delivery, drug modification, cell adhesion, gene delivery, self-assembly materials, anti-tumor, cell adhesion, tissue engineering, surface antifouling, cell cryopreservation, etc. Based on the above findings, the inventor completed the present invention.

Specifically, the inventors prepared an oxazoline polymer containing amino and/or hydroxyl groups in the side chain by optimizing the polymerization conditions (under inert gas protection, using methyl trifluoromethanesulfonate or benzoyl trifluoromethanesulfonate as an initiator, using N,N-2-methylacetamide as a preferred solvent, and heating conditions).

The oxazoline polymer containing amino groups in the side chain of the present invention can be used in the fields of antibacterial, antifungal, antiviral, anti-mite, antitumor, cell adhesion, tissue engineering, drug modification, protein modification, protein protection, drug synergy, drug delivery, gene delivery and self-assembly materials.

The present invention also synthesizes a type of oxazoline monomers with protected hydroxyl groups in the side chains. The oxazoline polymers with hydroxyl groups in the side chains prepared by polymerization reaction can be used in the fields of surface antifouling, protein modification and protection, cell protection, tissue and organ cryoprotection, and drug modification.

The oxazoline polymer having an amino group and a hydroxyl group in the side chain obtained by the present invention has the functions of both an oxazoline polymer having an amino group and an oxazoline polymer having a hydroxyl group in the side chain.

the term

In the present invention, unless otherwise specified, the terms used have the general meanings well known to those skilled in the art.

When substituents are described by conventional chemical formulas written from left to right, the substituents also include chemically equivalent substituents that would result if the formula were written from right to left. For example, _-CH2O- is equivalent to _-OCH2- .

Throughout the specification, the term "optionally substituted" or "may be substituted" etc. is used to indicate that the group may or may not be further substituted or fused (to form a polycyclic system) with one or more non-hydrogen substituents. Suitable chemically suitable substituents for a particular functional group will be apparent to those skilled in the art.

As used herein, the term "alkyl" refers to a straight or branched chain alkyl group containing several carbon atoms, wherein " _C1 - _C15 alkyl" refers to a straight or branched chain alkyl group having 1 to 15 carbon atoms, including alkyl groups of ₁ , ₂ , 3, ₄ , ₅ , 6, ₇ , ₈ , 9, 10, 11, 12, 13, 14 or 15 carbon atoms, and alkyl groups are preferably C1- _C2 , _C1 - _C3 , C1- _C4 , C1- _C5 , C1 _{- C6} , _{C1- C7} , C1- _C8 , C1 _{- C9} , _{C1 - C10} , C2 _- C3, _C2 - _C4 , _C2 - _C5 , _C2 - _C6 , C3- _C4 , _C3 -C5, _C3 - _C6 , C3- _C -C ₇ , C ₃ -C ₈ , C ₄ -C ₅ , C ₄ -C ₆ or C _5-6 . Typical "alkyl" includes, but is not limited to, methyl, ethyl, propyl, isopropyl, n-butyl, tert-butyl, isobutyl, The term "alkyl" refers to alkyl radicals such as pentyl, isopentyl, heptyl, 4,4-dimethylpentyl, octyl, 2,2,4-trimethylpentyl, nonyl, decyl, undecyl, dodecyl, etc. In the present invention, alkyl radicals also include substituted alkyl radicals. "Substituted alkyl radicals" refer to alkyl radicals that are substituted at one or more positions, especially 1 to 4 substituents, which can be substituted at any position.

As used herein, the term "C ₁ -C ₁₅ alkoxy" refers to a straight or branched alkoxy group having 1 to 15 carbon atoms, having a C ₁ -C ₁₅ alkyl-O-structure, C ₁ -C ₁₅ alkoxy group includes but is not limited to methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, isobutoxy, tert-butoxy, pentyloxy, hexyloxy, etc., preferably ethoxy. C ₁ -C ₁₅ alkoxy group also includes substituted C ₁ -C ₁₅ alkoxy group.

As used herein, the term "C ₁ -C ₁₅ alkylhydroxyl" refers to -C ₁ -C ₁₅ alkylene-OH, wherein -C ₁ -C ₁₅ alkylene has the above-mentioned definition, and C ₁ -C ₁₅ alkylhydroxyl includes but is not limited to -CH ₂ OH and -CH ₂ CH ₂ OH. C ₁ -C ₁₅ alkylhydroxyl also includes substituted C ₁ -C ₁₅ alkylhydroxyl.

As used herein, the term "C ₁ -C ₁₅ alkylsulfonyl" refers to C ₁ -C ₁₅ alkyl S(═O) ₂ —.

As used herein, the term "C ₁ -C ₁₅ alkyl-C ₆ -C ₁₅ aryl" refers to a -C ₁ -C ₁₅ alkyl-C ₆ -C ₁₅ aryl group, such as -CH ₂ CH ₂ CH ₂ Ph, -Bn.

As used herein, the term "C ₁ -C ₁₅ alkyl ester group" refers to a C ₁ -C ₁₅ alkyl C(═O)—O— or -(═O)—OC ₁ -C ₁₅ alkyl group.

As used herein, the term "thio-C1-C15 alkylester group" refers to a _C1 - _C15 alkyl group C(=S)-O- or -(=S)-OC1 _{- C15} alkyl group.

As used herein, the term "guanidino" refers to NHC(=NH)NH-.

As used herein, the term "C ₁ -C ₁₅ alkylcarboxyl" refers to -C ₁ -C ₁₅ alkylCOOH, for example, -CH ₂ COOH, -CH ₂ CH ₂ COOH, -CH ₂ CH ₂ CH ₂ COOH, -CH ₂ CH ₂ CH ₂ CH ₂ COOH, preferably -CH ₂ COOH, -CH ₂ CH ₂ COOH, wherein the alkyl group may be substituted.

As used herein, the term "C ₁ -C ₁₅ alkylaldehyde group" refers to -C ₁ -C ₁₅ alkylCHO, for example, -CH ₂ CHO, -CH ₂ CH ₂ CHO, -CH ₂ CH ₂ CH ₂ CHO, -CH ₂ CH ₂ CH _{2 CHO} , preferably -CH ₂ CHO, -CH ₂ CH ₂ CHO, wherein the alkyl group may be substituted.

As used herein, the term "C ₁ -C ₁₅ alkylamino" refers to -C ₁ -C ₁₅ alkyl-NH ₂ , such as -CH ₂ -NH ₂ , -CH ₂ CH ₂ -NH ₂ , -CH ₂ CH ₂ CH ₂ -NH ₂ , -CH ₂ CH ₂ CH ₂ CH ₂ -NH ₂ , preferably -CH ₂ -NH ₂ , -CH ₂ CH ₂ -NH _2. The H in the amino group (-NH ₂ ) may also be substituted.

As used herein, the term "alkenyl" refers to a straight or branched hydrocarbon having at least 2 carbon atoms and at least one double bond. Alkenyl can include any number of carbon atoms, wherein "C2-C15 alkenyl" refers to a straight or branched hydrocarbon having 2-15 carbon atoms and at least one double bond, such as _{C2 ,} C2- _C3 , _C2 - _C4 , C2-C5, _C2 - _C6 , _{C2 -C7 , C2 - C8} , _C2 - _C9 , _C2 - _C10 , _C3 , _C3 - _C4 , _C3 - _C5 , _C3 - _C6 , _C4 , _C4 - _C5 , C4 _{- C6} , _C5 , C5 _{- C6} , and _C6 . Alkenyl can have any suitable number of double bonds, including but not limited to 1, 2, 3, 4, 5 or more. Examples of alkenyl include but are not limited to vinyl (vinyl group), propenyl, isopropenyl, 1-butenyl, 2-butenyl, isobutenyl, butadienyl, 1-pentenyl, 2-pentenyl, isopentenyl, 1,3-pentadienyl, 1,4-pentadienyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 1,3-hexadienyl, 1,4-hexadienyl, 1,5-hexadienyl, 2,4-hexadienyl or 1,3,5-hexatrienyl. Like the above-mentioned alkyl, alkenyl can be substituted or unsubstituted.

As used herein, the term "alkynyl" refers to a straight or branched hydrocarbon having at least 2 carbon atoms and at least one triple bond. Alkynyl can include any number of carbon atoms, and "C2- _C15 alkynyl" refers to a straight or branched hydrocarbon having 2-15 carbon atoms and at least one triple bond, such as _C2 , _C2 - _C3 , _C2 - _C4 , _C2 -C5, _C2 - _C6 , _{C2 -C7 , C2} - _C8 , _C2 - _C9 , C2- _C10 , _C3 , _C3 - _C4 , _C3 - _C5 , C3 _{- C6} , _C4 , _C4 - _C5 , _C4 - _C6 , _C5 , _C5 - _C6 , and _C6 . Examples of alkynyl include, but are not limited to, ethynyl, propynyl, 1-butynyl, 2-butynyl, isobutynyl, sec-butynyl, butadiynyl, 1-pentynyl, 2-pentynyl, isopentenyl, 1,3-pentadiynyl, 1,4-pentadiynyl, 1-hexynyl, 2-hexynyl, 3-hexynyl, 1,3-hexadiynyl, 1,4-hexadiynyl, 1,5-hexadiynyl, 2,4-hexadiynyl, or 1,3,5-hexatriynyl. Like the above-mentioned alkyl, alkynyl can be substituted or unsubstituted.

The term "aryl" refers to an aromatic cyclic hydrocarbon compound group, wherein "C6-C15 aryl" refers to an aromatic cyclic hydrocarbon compound group containing 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15 ring carbon atoms, with 1-5 rings, especially monocyclic and bicyclic groups, such as phenyl, biphenyl or naphthyl. Where there are two or more aromatic rings (bicyclic, etc.), the aromatic rings of the aryl group can be connected by a single bond (such as biphenyl) or fused (such as naphthalene, anthracene, etc.). "Substituted aryl" means that one or more positions in the aryl are substituted, especially 1-3 substituents, which can be substituted at any position.

As used herein, the term "heteroaryl" refers to a heteroaromatic system containing 1-3 atoms selected from N, O, and S, wherein "5-15 membered heteroaryl" refers to a 5-15 membered heteroaromatic system containing 1-3 atoms selected from N, O, and S. The heteroaryl is preferably a 5- to 10-membered ring, more preferably a 5- or 6-membered ring, and includes, but is not limited to, pyrrolyl, pyrazolyl, imidazolyl, oxazolyl, isoxazolyl, thiazolyl, thiadiazolyl, isothiazolyl, furanyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, triazinyl, triazolyl, tetrazolyl, and the like. "Heteroaryl" may be substituted or unsubstituted, and when substituted, the substituent is preferably one or more of the following groups independently selected from alkyl, deuterated alkyl, haloalkyl, alkoxy, haloalkoxy, alkenyl, alkynyl, alkylthio, alkylamino, halogen, amino, nitro, hydroxy, mercapto, cyano, cycloalkyl, heterocyclyl, aryl, heteroaryl, cycloalkylthio, oxo, carboxyl and carboxylate.

As used herein, the term "cycloalkyl" refers to a fully saturated cyclic hydrocarbon group having several carbon atoms, wherein "C ₃ -C ₁₅ cycloalkyl" refers to a fully saturated cyclic hydrocarbon group having 3-15 carbon atoms, preferably C ₃ -C ₄ , C ₃ -C ₅ , C 3 -C 6, C ₃ -C _{7 ,} C ₃ -C ₈ , C _{3 -C 9} , C ₃ -C _10. "Substituted C ₃ -C ₁₅ cycloalkyl" means that one or more positions in the cycloalkyl are substituted, especially 1-4 substituents, which can be substituted at any position, including but not limited to cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, etc. In the present invention, "cycloalkyl" is intended to include "substituted cycloalkyl".

As used herein, the term "cycloalkenyl" refers to an unsaturated cyclic hydrocarbon group having several carbon atoms and 1-3 double bonds, wherein " _C4 - _{C15cycloalkenyl} " refers to an unsaturated cyclic hydrocarbon group having 4-15 carbon atoms and 1-3 double bonds, preferably _C6 - _{C10cycloalkenyl} , _C4 - _{C6cycloalkenyl} , cycloalkenyl includes but is not limited to cyclobutenyl, cyclopentenyl, cyclohexenyl.

As used herein, the term "heterocyclyl" refers to a fully saturated or partially unsaturated cyclic group having a number (greater than or equal to 3) of ring atoms and 1-3 heteroatoms, wherein "5-15 membered heterocyclyl" refers to a fully saturated or partially unsaturated cyclic group having 5-15 ring atoms and 1-3 heteroatoms (including but not limited to 3-7 membered monocyclic, 6-11 membered bicyclic, or 8-12 membered tricyclic system). Among them, the nitrogen atom or sulfur atom can be oxidized, and the nitrogen atom can also be quaternized. The heterocyclic group can be attached to the residue of any heteroatom or carbon atom of the ring or ring system molecule. Typical monocyclic heterocycles include, but are not limited to, azetidinyl, pyrrolidinyl, oxetanyl, pyrazolinyl, imidazolinyl, imidazolidinyl, oxazolidinyl, isoxazolidinyl, thiazolidinyl, isothiazolidinyl, tetrahydrofuranyl, piperidinyl, piperazinyl, 2-oxopiperazinyl, 2-oxopiperidinyl, 2-oxopyrrolidinyl, hexahydroazepinyl, 4-piperidonyl, tetrahydropyranyl, morpholinyl, thiomorpholinyl, thiomorpholinyl sulfoxide, thiomorpholinyl sulfone, 1,3-dioxanyl and tetrahydro-1,1-dioxythiophene, and the like. Polycyclic heterocyclic groups include spirocyclic, condensed and bridged heterocyclic groups; wherein the spirocyclic, condensed and bridged heterocyclic groups involved are optionally connected to other groups through single bonds, or further connected to other cycloalkyl, heterocyclic, aryl and heteroaryl groups through any two or more atoms on the ring; the heterocyclic group may be substituted or unsubstituted, and when substituted, the substituent is preferably one or more of the following groups, which are independently selected from alkyl, deuterated alkyl, haloalkyl, alkoxy, haloalkoxy, alkenyl, alkynyl, alkylthio, alkylamino, halogen, amino, nitro, hydroxyl, sulfhydryl, cyano, cycloalkyl, heterocyclic, aryl, heteroaryl, cycloalkylthio, oxo, carboxyl and carboxylate groups. Heterocyclic groups include, but are not limited to, tetrahydropyrrolyl, tetrahydrofuranyl, piperidinyl, piperazinyl, etc.

When the substituent is a non-terminal substituent or a related group removes a H atom, it is a subunit of the corresponding group, usually a divalent group, for example, an alkyl group removes a H atom to become an alkylene group (for example: methylene, ethylene, propylene, isopropylene (such as ), butylene (such as ), pentylene (such as ), hexamethylene (such as ), heptylene (such as ) etc.), cycloalkyl corresponds to cycloalkylene (such as: etc.), heterocyclic groups correspond to heterocyclic groups (such as: ), cycloalkyl corresponding to heterocyclyl (such as: The alkoxy group corresponds to an alkyleneoxy _group ( _-CH2O- , _{-CH2CH2 - O-CH2-, -CH2OCH2CH2CH2- ) and} the like _.

As used herein, the term "plurality" means two or more.

As described herein, the compounds of the present invention can be replaced with any number of substituents or functional groups to expand their scope of inclusion. Generally, the term "substituted" appears before or after the term "optional", and the general formula of the substituent included in the present invention refers to the use of a specified structural substituent to replace the hydrogen free radical. When multiple positions in a specific structure are replaced by multiple specific substituents, each position of the substituent can be the same or different. The term "substituted" used herein includes all allowed organic compound substitutions. In a broad sense, allowed substituents include non-cyclic, cyclic, branched non-branched, carbocyclic and heterocyclic, aromatic and non-aromatic organic compounds. In the present invention, heteroatom nitrogen can have a hydrogen substituent or any allowed organic compound described above to supplement its valence state. In addition, the present invention is not intended to limit the allowed substitution of organic compounds in any way.

In the present invention, unless otherwise specified, the groups include corresponding substituted groups and subunits, for example, alkyl includes substituted alkyl, cycloalkyl includes substituted cycloalkyl, aryl includes substituted aryl, heteroaryl includes substituted heteroaryl, heterocyclyl includes substituted heterocyclyl, etc. It should be understood by those skilled in the art that the combinations of substituents contemplated by the present invention are those that are stable or chemically feasible. Typical substitutions include, but are not limited to, one or more of the following groups: such as hydrogen, deuterium, halogen (e.g., monohalogen substituents or polyhalogen substituents, the latter such as trifluoromethyl or alkyl containing Cl ₃ ), nitrile, nitro, oxygen (such as =O), trifluoromethyl, trifluoromethoxy, cycloalkyl, C2-C6 alkenyl, C4-C10 cycloalkenyl, C2-C6 alkynyl, heterocyclyl, aryl, heteroaryl, OR _a , SR _a , S(=O) _Re , S(=O) _{2 Re} , P(=O) _{2 Re} , S(=O) ₂ OR _e , P(=O) ₂ OR _e , NR _b R _c , NR _b S(=O) _{2 Re} , NR _b P(=O) _{2 Re} , S(=O) ₂ NR _b R _c , P(=O) ₂ NR _b R _c , C(=O)OR _d , C(=O) _Ra , C(＝O)NR _b R _c , OC(＝O)R _a , OC(＝O)NR _b R _c , NR _b C(＝O)OR _e , NR _d C(＝O)NR _b R _c , NR _d S(＝O) ₂ NR _b R _c , NR _d P(＝O) ₂ NR _b R _c , NR _b C(＝O)R _a , or NR _b P(＝O) ₂ R _e , wherein _Ra occurring herein independently represents hydrogen, deuterium, C1-C6 alkyl, C3-C8 cycloalkyl, C2-C6 alkenyl, C3-C10 cycloalkenyl, C2-C6 alkynyl, 3-8 membered heterocyclyl, 5-14 membered heteroaryl or C6-C14 aryl, and R _b , R _c and R _d can independently represent hydrogen, deuterium, C1-C6 alkyl, C3-C8 cycloalkyl, 3-8 membered heterocyclyl, 5-14 membered heteroaryl or C6-C14 aromatic ring, or R _b and R _c together with N atom can form a heterocycle; R _e can independently represent hydrogen, C1-C6 alkyl, C3-C8 cycloalkyl, C2-C6 alkenyl, C3-C6 cycloalkenyl, C2-C6 alkynyl, 3-8 membered heterocyclyl, 5-14 membered heteroaryl or C6-C14 aromatic ring. The above typical substituents, such as alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkynyl, heterocyclyl, heteroaryl or aryl and their corresponding substituent groups and subunits can be optionally substituted, wherein the alkyl, cycloalkyl, cycloalkenyl, heterocyclyl, heteroaryl or aryl have the above-mentioned definitions.

As used herein, the term "substituted" means that any one or more hydrogens on the designated atom are replaced with a substituent selected from the designated substituent, provided that the normal valency of the designated atom is not exceeded and that the compound produced by the substitution is stable, i.e., a compound that can be isolated, characterized, and tested for biological activity.

Unless otherwise stated, any heteroatom with insufficient valence is assumed to have sufficient hydrogen atoms to complete its valence.

As used herein, the term "statistic coplymer" or "random" refers to a polymer obtained by simultaneous polymerization of two or more monomers that are randomly connected, wherein at least one monomer has an amino or hydroxyl structure as a side chain.

As used herein, the term "block type" refers to a polymer formed by connecting different segments obtained by sequential polymerization of two or more monomers, wherein at least one of the monomers has an amino or hydroxyl structure as a side chain.

The structural formula or name of the monomer given in the present invention may only exemplify one specific configuration or not give a specific configuration, and the monomer may also include all other configurations corresponding to the given configuration.

Oxazoline polymers of the present invention

The oxazoline polymer of the present invention includes an oxazoline polymer containing an amino group in the side chain and/or an oxazoline polymer containing a hydroxyl group in the side chain. The oxazoline polymer containing an amino group in the side chain includes an oxazoline polymer in which the side chain amino group is substituted; similarly, the oxazoline polymer containing a hydroxyl group in the side chain includes an oxazoline polymer in which the side chain hydroxyl group is substituted. The oxazoline polymer of the present invention also includes an oxazoline polymer derivative, wherein the derivative refers to an amino group in the polymer side chain being converted into other functional groups such as guanidine groups, or the amino group contained in the side chain being connected to other molecules such as drug molecules, fluorescent small molecules, protective groups, etc. through chemical reactions; the end of the polymer is chemically modified, such as connecting a fluorescent molecule or a drug molecule.

The oxazoline polymer of the present invention comprises one or more repeating units represented by formula _E1 and/or formula _E2 ,

and optionally comprising and/or wherein the repeating unit _E1 and/or the formula _E2 may be optionally connected to the repeating unit B and/or C.

1. Oxazoline polymers with amino groups in the side chains

The oxazoline polymer containing amino groups in the side chain of the present invention refers to a polymer containing one or more repeating units of formula _E2 ; it may also contain other repeating units B and/or C.

An exemplary oxazoline polymer having an amino group in the side chain has a structure shown in Formula II:

Preferably, the oxazoline polymer having an amino group in the side chain shown in Formula II has a structure shown in Formula V:

Preferably, the oxazoline polymer having an amino group in the side chain shown in Formula II has a structure shown in Formula VII:

Preferably, the oxazoline polymer having an amino group in the side chain shown in formula II has a structure as shown in formula VIII:

In the above formulas,

In the formula, R ₆ is defined as the structural part other than the carboxyl group in the molecular structure of a natural amino acid or a non-natural amino acid; n, x, y, z, A, m, m', R ₁ , R' ₁ , R ₂ , _Ra and R _b are defined as above; x, y and z are calculated by dividing the number of repeating units of a certain side chain by the total number of repeating units, for example, the percentage of the side chain amino group is the number of units containing the side chain amino group divided by the total number of units containing the side chain amino group and other functional groups in the side chain.

Preferably, the natural amino acid is selected from the following group: glycine, alanine, valine, leucine, isoleucine, phenylalanine, tryptophan, tyrosine, aspartic acid, asparagine, glutamic acid, lysine, glutamine, methionine, serine, threonine, cysteine, proline, histidine, arginine, etc., and derivatives derived from the above amino acids; the unnatural amino acids include β-amino acids, γ-amino acids, δ-amino acids, and ε-amino acids.

Preferably, the derivatives derived from the above-mentioned amino acids are derivatives in which the carboxylic acid groups on the amino acids are esterified (e.g., benzyl esterification, tert-butyl esterification, methyl esterification, etc.), derivatives in which the hydrogen atoms on the amino groups on the amino acids are substituted (e.g., tert-butyloxycarbonyl (Boc), benzyloxycarbonyl (Cbz), fluorenylmethyloxycarbonyl (Fmoc), etc.), derivatives in which the hydrogen atoms on the hydroxyl groups on the amino acids are substituted (e.g., tert-butyl (tBu)), derivatives in which the hydrogen atoms on the free thiol groups on the amino acids are substituted (e.g., trityl (Trt), benzyl, benzyl ester, etc.).

Preferably, the amino acid structure is L-type, D-type or DL-type.

Preferably, the amino or guanidinium functional groups in the oxazoline polymer structure are in the form of hydrochloride, hydrobromide, formate, acetate, or trifluoroacetate.

Preferably, the amino groups in the oxazoline polymer structure are converted into guanidine functional groups.

Preferably, the amino group in the polymer structure is protected by a protecting group, and the amino protecting group is selected from the following group: tert-butyloxycarbonyl (Boc), benzyloxycarbonyl (Cbz), fluorenylmethyloxycarbonyl (Fmoc), phthaloyl (Pht), acetyl (Ac), trifluoroacetyl (Tfa), benzyl (Bn), triphenylmethyl (Tr).

Preferably, the oxazoline polymer structure is a ternary, quaternary or higher blend or block copolymer.

Preferably, the terminal of the oxazoline polymer structure is converted into other functional groups such as hydroxyl, amino, ester, etc.

Preferably, after the terminal of the oxazoline polymer structure is converted into other functional groups such as hydroxyl, amino, ester, etc., it is further modified with other active molecules such as dye molecules and drug molecules to obtain terminal functionalized oxazoline polymers.

2. Oxazoline polymers are oxazoline polymers with hydroxyl groups in the side chains

The oxazoline polymer containing hydroxyl groups in the side chain of the present invention refers to a polymer containing one or more repeating units of formula _E1 ; and may also contain one or more repeating units B and/or C.

An exemplary oxazoline polymer having an amino group in the side chain has a structure as shown in Formula I:

Preferably, the oxazoline polymer having a hydroxyl group in the side chain of formula I has a structure as shown in IV:

wherein n, x, y, z, m, m', R ₁ , R' ₁ and R ₂ are as defined above.

3. Oxazoline polymers with amino and hydroxyl groups in the side chains

The oxazoline polymer containing amino and hydroxyl groups in the side chain of the present invention refers to a polymer containing repeating units of formula _E1 and _E1 ; it may also contain one or more repeating units B and/or C.

An exemplary oxazoline polymer having an amino group and a hydroxyl group in the side chain has a structure as shown in Formula III:

Preferably, the oxazoline polymer having amino and hydroxyl groups in the side chain of formula III has a structure as shown in formula VI or formula IX:

Among them, 0%＜w<100%; 0%≤x ₁ <100%; the calculation method of w and x1 is the same as x, y, and z.

m, m', n, x, y, z, _R1 , _R'1 , _R2 , _Ra , _Rb and _R6 are as defined above.

The polymer monomer of the present invention

The polymer monomers of the present invention include monomers represented by formula _E'1 and/or _E'2 , and optionally monomers represented by formula B' and/or formula C'.

Preferably, the _E'2 oxazoline monomer has a structure as shown in formula E" ₂ :

Preferably, the oxazoline monomer of formula _E'1 has a structure as shown in formula E" ₁ :

In the above formulae, _R'1 , m', q', _L1 ', _R1 , m, q, _L1 , _Ra , _Rb , _P1 , _P2 and _R7 have the same meanings as described above.

A method for synthesizing an oxazoline monomer having a side chain hydroxyl group of formula E" ₁ , the specific steps comprising:

(2) In a second inert solvent, compound 2 is reacted with a base to obtain a monomer of formula E"₁; wherein m, _P2 , and _R1 are as defined above.

X is a leaving group, for example, Br, Cl, I, OTs, OMs, preferably Cl.

The substitution refers to substitution by a substituent selected from the group consisting of halogen, hydroxy, amino, C ₁ -C ₆ alkyl, and C ₁ -C ₆ alkoxy.

Preferably, the base is selected from the group consisting of sodium hydroxide, potassium hydroxide, triethylamine or N,N-diisopropylethylamine, or a combination thereof; preferably sodium hydroxide.

Preferably, the reaction temperature is selected from the following range: 25°C-100°C; preferably 70°C.

Preferably, the method for preparing the monomer of formula IX further comprises the steps of:

(1) In a first inert solvent, compound 1 is reacted with H ₂ N(CH ₂ ) ₂ X to obtain compound 2; R ₆ , P ₂ , X, and n ₁ are as defined above.

Preferably, in step (1), the reaction temperature is 0-70°C; more preferably, 0-25°C.

Preferably, in step (1), the reaction time is 6 hours to 1 day.

Preferably, in step (1), H ₂ N(CH ₂ ) ₂ X is in the form of its hydrochloride or hydrobromide.

Preferably, in step (1), H ₂ N(CH ₂ ) ₂ X is in the form of its hydrochloride or hydrobromide.

Preferably, in step (1), DIEA is replaced by Et ₃ N.

Preferably, the step (1) is to dissolve compound 1 and DIEA in a first inert solvent, add EDCI and HOBT in an ice bath, stir and react for 30 minutes, then add H ₂ N(CH ₂ ) ₂ X; after reacting at room temperature for 8 hours, wash the reaction mixture twice with deionized water and 5% citric acid aqueous solution, respectively, dry and concentrate the organic phase, and separate and purify by column to obtain compound 2.

Preferably, in step (1), the first inert solvent is independently selected from the following group: DCM, DMF, THF, DMAc; preferably DCM.

Preferably, the step (2) is to dissolve the compound 2 obtained in (1) in a second inert solvent, add a base to react at 70° C. under the protection of an inert gas; after the reaction is completed, remove the solvent, add dichloromethane to dissolve, and wash twice with deionized water, dry and concentrate the organic phase, and then purify it by reduced pressure distillation to obtain a monomer of formula E” ₁ .

In another preferred embodiment, in the step (2), the second inert solvent is dry.

In another preferred embodiment, in step (2), the second inert solvent is independently selected from the following group: methanol, ethanol, acetonitrile, or a combination thereof; preferably selected from: ethanol.

In another preferred embodiment, in the step (2), the reaction is carried out under the protection of an inert gas; the inert gas is preferably nitrogen, argon, or a combination thereof.

Preparation method of oxazoline polymer of the present invention

The oxazoline polymer of the present invention is prepared by the preparation method of the polymer of the present invention.

Preparation of homopolymer: In an organic solvent, in the presence of an initiator, an oxazoline monomer is polymerized to obtain an oxazoline homopolymer having an amino group in the side chain.

Preparation of the copolymer: firstly, in an organic solvent, in the presence of an initiator, polymerize an oxazoline monomer; after the polymerization reaction is completed, add another oxazoline monomer to carry out a polymerization reaction, and so on. When the oxazoline monomers are more, various monomers can be added in sequence to carry out a polymerization reaction, thereby forming a block-type oxazoline copolymer; when the oxazoline monomers are two or more, in an organic solvent, the two or more oxazoline monomers are mixed, and then in the presence of an initiator, a polymerization reaction is carried out to form a blended oxazoline copolymer.

1. Preparation method of oxazoline polymer containing amino group in the side chain

In an organic solvent, in the presence of an initiator, under inert gas protection and heating conditions, an oxazoline monomer represented by formula _E'2 and optionally a monomer of formula B' and/or formula C' are polymerized to obtain an oxazoline polymer containing an amino group in the side chain.

Preferably, the preparation method comprises the following steps:

In an organic solvent and inert gas protection, in the presence of an initiator and under heating conditions, an oxazoline monomer containing at least one side chain amino group is polymerized to obtain a side chain amino group-protected oxazoline polymer; after removing the amino protecting group, a 2-oxazoline polymer with an amino group as a side chain is obtained; after guanidine group functionalization, an oxazoline polymer with a side chain guanidine group is obtained.

Preferably, the organic solvent is selected from the group consisting of DMAc, DMF, or a combination thereof; preferably DMAc.

Preferably, the inert gas is selected from the group consisting of N ₂ , Ar; preferably Ar.

Preferably, the initiator is selected from the group consisting of MeOTf, BzOTf; preferably MeOTf.

Preferably, the heating condition has a temperature range of 80°C-140°C; preferably 120°C.

Preferably, the polymerization reaction time is 2h-8h; preferably 6h.

Preferably, the oxazoline copolymer with side chain amino groups is a polymer obtained by copolymerizing two or more monomers mixed in a set ratio.

Preferably, when the oxazoline monomers are two or more, the method comprises the steps of:

In an organic solvent, in the presence of an initiator, firstly, an oxazoline monomer is polymerized;

After the above polymerization reaction is completed, another oxazoline monomer is added to carry out polymerization reaction, thereby forming a block oxazoline copolymer.

By analogy, when there are more kinds of oxazoline monomers, various monomers can be added in sequence to carry out polymerization reaction.

Preferably, when the oxazoline monomers are two or more, the method comprises the steps of: mixing the two or more oxazoline monomers in an organic solvent, and then performing a polymerization reaction in the presence of an initiator to form an oxazoline copolymer.

It should be understood that one, two, three or more oxazoline monomers are polymerized and at least one of the monomer side chains is an amino group or a protected amino group.

2. Preparation method of oxazoline polymer containing hydroxyl groups on the side chain

Preferably, the preparation method comprises the following steps:

In an organic solvent and inert gas protection, in the presence of an initiator and under heating conditions, an oxazoline monomer containing at least one side chain hydroxyl group is polymerized to obtain a side chain hydroxyl protected oxazoline polymer; after removing the hydroxyl protecting group, an oxazoline polymer with a hydroxyl side chain is obtained.

Preferably, the organic solvent is selected from the group consisting of DMAc, DMF, MeCN, PhCN, or a combination thereof; preferably DMAc.

Preferably, the inert gas is selected from the group consisting of N ₂ , Ar; preferably Ar.

Preferably, the initiator is selected from the group consisting of MeOTf, BzOTf, CH ₃ (CH ₂ ) ₅ Br, CH ₃ (CH ₂ ) ₅ Ots, or a combination thereof; preferably MeOTf.

Preferably, the heating condition has a temperature range of 80°C-140°C; preferably 80°C-120°C.

Preferably, the polymerization reaction time is 2h-8h; preferably 6h.

Preferably, the oxazoline copolymer with side chain hydroxyl groups is a polymer obtained by copolymerizing two or more monomers mixed in a set ratio.

Preferably, when the oxazoline monomers are two or more, the method comprises the steps of:

In an organic solvent, in the presence of an initiator, firstly, an oxazoline monomer is polymerized;

After the above polymerization reaction is completed, another oxazoline monomer is added to carry out polymerization reaction, thereby forming a block oxazoline copolymer.

By analogy, when there are more kinds of oxazoline monomers, various monomers can be added in sequence to carry out polymerization reaction.

Preferably, when the oxazoline monomers are two or more, the method comprises the steps of: mixing the two or more oxazoline monomers in an organic solvent, and then performing a polymerization reaction in the presence of an initiator to form a blended oxazoline copolymer.

It should be understood that one, two, three or more oxazoline monomers are polymerized, and at least one monomer side chain is a hydroxyl group or a protected hydroxyl group, and the other monomers can be amino-protected oxazoline monomers or any other polymerizable monomers.

3. Preparation method of oxazoline polymer containing amino and hydroxyl groups in the side chain

The preparation method comprises the following steps: in an organic solvent, in the presence of an initiator and under heating conditions, polymerizing an oxazoline monomer represented by formula _E'2 and an oxazoline monomer represented by formula _E'1 , and optionally oxazoline monomers of other structures, to obtain an oxazoline polymer having amino and hydroxyl groups in the side chains; wherein _E'2 and _E'1 are as defined above.

Preferably, the oxazoline monomer optionally having other structures is a monomer of formula B' or formula C'.

In a preferred embodiment, one or more oxazoline monomers represented by formula E" ₂ and one or more E" ₁ and optionally B' and/or C' monomers are polymerized in an organic solvent in the presence of an initiator and under heating conditions to obtain an oxazoline polymer having amino-protected and hydroxyl-protected side chains; after removing the protecting groups, an oxazoline polymer having amino and hydroxyl groups in the side chains is obtained; optionally, the amino groups in the oxazoline polymer having amino and hydroxyl groups are functionalized to guanidine groups to obtain an oxazoline polymer having guanidine groups and hydroxyl groups in the side chains.

Preferably, the oxazoline copolymer containing amino groups and hydroxyl groups in the side chain is a polymer obtained by copolymerizing two or more monomers mixed in a set ratio.

Preferably, when the oxazoline monomers are two or more, the method comprises the steps of:

In an organic solvent, in the presence of an initiator and under heating conditions, an oxazoline monomer (amino or hydroxyl side chain) is first polymerized;

After the above polymerization reaction is completed, another oxazoline monomer (hydroxyl or amino side chain) is added to carry out polymerization reaction, thereby forming a block oxazoline copolymer;

By analogy, when there are more kinds of oxazoline monomers, various monomers can be added in sequence to carry out polymerization reaction.

Preferably, when the oxazoline monomers are two or more, the method comprises the steps of: mixing oxazoline having amino and hydroxyl groups in the side chains and any one or more other polymerizable monomers (preferably B' and/or C') in an organic solvent, and then performing a polymerization reaction in the presence of an initiator to form a blended oxazoline copolymer.

It should be understood that two, three or more oxazoline monomers are polymerized, and at least two of the monomer side chains are amino or hydroxyl groups or protected amino or hydroxyl groups, and the other monomers can be any other polymerizable monomers.

Use of the polymers of the invention

1. Oxazoline monomers with amino groups on the side chains

The oxazoline monomer containing amino groups in the side chain can be used in biomedical fields such as antibacterial, antitumor, tissue engineering, drug and gene delivery, drug modification, cell adhesion and self-assembly materials.

Preferably, the antibacterial material is in the form of a solution or a surface coating.

2. Oxazoline polymers with hydroxyl groups on the side chains

The oxazoline polymer with side chain hydroxyl groups of the present invention is used in the fields of surface antifouling, protein modification and protection, cell protection, tissue and organ cryoprotection, and drug modification.

Preferably, the oxazoline polymer having side chain hydroxyl groups is used for surface antifouling coating.

3. Oxazoline polymers with amino and hydroxyl groups in the side chains

The oxazoline polymer containing amino and hydroxyl groups in the side chain can be used in biomedical fields such as antibacterial, antitumor, tissue engineering, drug and gene delivery, drug modification, cell adhesion, self-assembly materials, surface antifouling, cell cryopreservation, and drug modification.

It should be understood that within the scope of the present invention, the above-mentioned technical features of the present invention and the technical features specifically described below (such as embodiments) can be combined with each other to form a new or preferred technical solution. Due to space limitations, they will not be described one by one here.

The main advantages of the present invention are:

1. The present invention provides a type of oxazoline polymer with amino groups in the side chain and a structure and preparation method thereof. Such oxazoline polymer with amino groups in the side chain and its derivatives can be used for research on polymer functions in biomedicine such as solution antibacterial, surface antibacterial, drug synergistic antibacterial, drug delivery, drug modification, cell adhesion, gene delivery, self-assembly materials, anti-tumor, cell adhesion, etc. Compared with the traditional oxazoline polymer based on methyl or ethyl oxazoline as the hydrophilic structure, the present invention expands the application scope of oxazoline polymer system in the field of biomedicine.

2. The present invention provides a synthesis of a class of oxazoline monomers containing hydroxyl groups on the side chains and the structure and preparation method of the polymers derived therefrom. Such oxazoline polymers and derivatives containing hydroxyl groups on the side chains can be used in the fields of surface antifouling, protein modification and protection, cell protection, tissue and organ cryoprotection, and drug modification.

3. The oxazoline polymer with amino and hydroxyl groups in the side chain provided by the present invention has the functions of both oxazoline polymer with amino groups in the side chain and oxazoline polymer with hydroxyl groups in the side chain.

The present invention will be further described below in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. The experimental methods in the following examples that do not specify specific conditions are usually carried out under normal conditions or according to the conditions recommended by the manufacturer. Unless otherwise specified, percentages and parts are weight percentages and weight parts. The experimental materials and reagents used in the following examples can be obtained from commercial channels unless otherwise specified.

Example

Preparation method of oxazoline monomer with side chain amino group

1. Preparation of N-Boc-2-(aminomethyl)oxazoline monomer

N-Boc glycine (3.5 g, 20 mmol) was dissolved in 100 mL of dichloromethane, and EDCI (5.8 g, 30 mmol), HOBT (2.7 g, 30 mmol), and triethylamine (8.3 mL, 60 mmol) were added in turn under an ice bath. After stirring for 30 minutes, 2-chloroethylamine hydrochloride (3.0 g, 26 mmol) was added. After stirring at room temperature for 8 hours, the reaction mixture was washed twice with 30 mL of deionized water and 30 mL of 5% citric acid aqueous solution, respectively. The organic phase was collected and dried over anhydrous magnesium sulfate. The organic phase was concentrated and purified by silica gel column chromatography to obtain the intermediate (3.3 g, yield 70%).

Sodium hydroxide (0.8 g, 20 mmol) was dissolved in 35 mL of ethanol in a dry single-mouth bottle, and then the intermediate (2.7 g, 10 mmol) was added, and heated to reflux under nitrogen protection, and the reaction was carried out for 2 h. The reaction solution was concentrated, and 30 mL of dichloromethane was added to dissolve, and extracted twice with deionized water. Finally, the organic phase was dried, concentrated, and then recrystallized to obtain a needle-shaped N-Boc-2-(aminomethyl)oxazoline monomer (1.3 g, yield 65.5%).

2. Preparation of N-Boc-2-(aminopropyl)oxazoline monomer

The experimental method is the same as 1, except that N-Boc aminobutyric acid (4.1 g, 20 mmol) is used to replace N-Boc glycine (3.5 g, 20 mmol).

3. Preparation of 2-(isobutyl)oxazoline monomer

Isovaleronitrile (1.6 g, 20 mmol), ethanolamine (1.2 g, 20 mmol) and zinc acetate (0.2 g, 1 mmol) were added to a dry single-mouth bottle, mixed and stirred, reacted at 140°C for 16 h under nitrogen protection, cooled to room temperature after the reaction was completed, and then 100 mL of dichloromethane was added to dissolve, and the organic phase was washed three times with 50 mL of deionized water, and the organic phase was dried over anhydrous magnesium sulfate, and the solvent was removed by vacuum rotary evaporation. 1 g of calcium hydride was added to the concentrated liquid, and finally purified by vacuum distillation to obtain an oily 2-(isobutyl)oxazoline monomer (1.5 mg, yield 58%).

4. Preparation of 2-(butyl)oxazoline monomer

The experimental method was the same as 3, except that n-valeronitrile (1.6 g, 20 mmol) was used instead of isovaleronitrile (1.6 g, 20 mmol).

5. Preparation of 2-(naphthylmethyl)oxazoline monomer

The experimental method was the same as 1, except that naphthylacetic acid (3.7 g, 20 mmol) was used instead of N-Boc glycine (3.5 g, 20 mmol).

Example 1 Synthesis of 2-aminomethyloxazoline homopolymer

In a nitrogen-protected glove box, the monomer N-Boc-2-(aminomethyl)oxazoline and the initiator methyl trifluoromethanesulfonate were dissolved in dry N,N-2-methylacetamide, 100 μL of the initiator methyl trifluoromethanesulfonate solution with a concentration of 0.2 M and 2 mL of the monomer N-Boc-2-(aminomethyl)oxazoline with a concentration of 0.2 M were added to the flask and mixed, and then stirred at 120° C. for 6 h;

After the polymerization reaction was completed, the mixture was cooled to room temperature and poured into cold petroleum ether (45 mL). The precipitated white flocs were collected by centrifugation, dried in a gas stream, and redissolved in tetrahydrofuran (1.5 mL). A large amount of cold petroleum ether was added for precipitation. This dissolution-precipitation process was repeated three times to obtain 72.6 mg (yield 90%) of N-Boc-2-(aminomethyl)oxazoline homopolymer.

The molecular weight Mn of the polymer obtained by MeOTf-initiated polymerization was identified by gel permeation chromatography (GPC) as 4100 and the molecular weight distribution PDI (Mw/Mn) as 1.22.

Then add 2 mL of trifluoroacetic acid to the drained polymer, gently shake it at room temperature for about 2 hours, blow off the excess trifluoroacetic acid, and dissolve the resulting viscous liquid in 0.5 mL of methanol, then add 45 mL of ice-cold ether to precipitate a white precipitate, and repeat the dissolution-precipitation process three times to obtain an oxazoline homopolymer with a side chain amino group. The deprotected polymer is dissolved again in 5 mL of ultrapure water, filtered and freeze-dried for the next biological activity test.

Comparative Example 1 Polymerization of 2-aminomethyloxazoline under the condition of acetonitrile as solvent

In a nitrogen-protected glove box, the monomer N-Boc-2-(aminomethyl)oxazoline and the initiator methyl trifluoromethanesulfonate were dissolved in a dry acetonitrile solvent, 100 μL of a 0.2M initiator methyl trifluoromethanesulfonate solution and 2 mL of a 0.2M monomer N-Boc-2-(aminomethyl)oxazoline were added to a flask and mixed, and then stirred for 6 hours under heating reflux conditions; most of the monomer raw materials were analyzed by thin layer chromatography analysis and did not participate in the polymerization reaction, and the reaction solution was cooled to room temperature, and the reaction mixture was poured into cold petroleum ether (45 mL), and a small amount of white floccules precipitated were collected by centrifugation, dried in an air flow, and redissolved in tetrahydrofuran (1.5 mL), and then a large amount of cold petroleum ether was added for precipitation. After this dissolution-precipitation process was repeated three times, no white solid was collected.

This Comparative Example 1 shows that when acetonitrile is used as a solvent (reaction temperature is about 80° C. (reflux temperature)), the polymerization reaction is difficult to proceed.

Example 2 Synthesis of Guanidine-derivatized Oxazoline Homopolymer

In a nitrogen-protected glove box, the monomer N-Boc-2-(aminopropyl)oxazoline and the initiator methyl trifluoromethanesulfonate (MeOTf) were dissolved in dry N,N-2-methylacetamide, 100 μL of the initiator methyl trifluoromethanesulfonate solution with a concentration of 0.2 M and 2 mL of the monomer N-Boc-2-(aminopropyl)oxazoline with a concentration of 0.2 M were added to the flask and mixed, and then stirred at 120 ° C for 6 h;

After the polymerization reaction was completed, the mixture was cooled to room temperature and poured into cold petroleum ether (45 mL). The precipitated white flocs were collected by centrifugation, dried in a gas stream, and redissolved in tetrahydrofuran (1.5 mL). A large amount of cold petroleum ether was added for precipitation. This dissolution-precipitation process was repeated three times to obtain 84.1 mg (yield 92%) of N-Boc-2-(aminopropyl)oxazoline homopolymer.

The molecular weight Mn of the polymer obtained by MeOTf-initiated polymerization was identified by gel permeation chromatography (GPC) as 4710 and the molecular weight distribution PDI (Mw/Mn) as 1.17.

Then, 2 mL of trifluoroacetic acid was added to the drained polymer, and the excess trifluoroacetic acid was blown off after gently shaking at room temperature for about 2 hours. The obtained viscous liquid was dissolved in 0.5 mL of methanol, and then 45 mL of ice-cold ether was added to precipitate a white precipitate. The dissolution-precipitation process was repeated three times to obtain an oxazoline homopolymer with a side chain amino group.

Then 50 mg of the drained polymer was dissolved in 1.5 mL of methanol, 90 mg of N, N-diisopropylethylamine and 106 mg of 1H-pyrazole-1-carboxamide hydrochloride were added, and the mixed solution was stirred at 55 ° C for 12 hours under nitrogen protection, and the excess solvent was spun off after heating and concentration. The viscous liquid was dissolved in 0.5 mL of methanol, and then 45 mL of frozen acetone was added to precipitate a white precipitate. The dissolution-precipitation process was repeated three times to obtain a side chain guanidine oxazoline homopolymer. The side chain guanidine oxazoline polymer was dissolved again with 5 mL of ultrapure water, filtered and freeze-dried for the next biological activity test.

Example 3 Synthesis of 2-(aminomethyl)oxazoline and 2-(isobutyl)oxazoline polymer blends

In a nitrogen-protected glove box, monomer N-Boc-2-(aminomethyl)oxazoline, monomer 2-(isobutyl)oxazoline and initiator methyl trifluoromethylsulfonate (MeOTf) were dissolved in dry N,N-2-methylacetamide, 100 μL of 0.2M initiator methyl trifluoromethylsulfonate solution, 0.8mL of 0.2M monomer N-Boc-2-(aminomethyl)oxazoline and 1.2mL of 0.2M monomer 2-(isobutyl)oxazoline were added to a flask and mixed, and then stirred at 120°C for 6h;

After the polymerization reaction was completed, the mixture was cooled to room temperature and poured into cold petroleum ether (45 mL). The precipitated white flocs were collected by centrifugation, dried in a gas stream, and redissolved in tetrahydrofuran (1.5 mL). A large amount of cold petroleum ether was added for precipitation. This dissolution-precipitation process was repeated three times to obtain 57.6 mg (yield 92%) of a copolymer of oxazoline with protected side chain amino groups.

The molecular weight Mn of the polymer obtained by MeOTf-initiated polymerization was determined by gel permeation chromatography (GPC) to be 3170 and the molecular weight distribution PDI (Mw/Mn) to be 1.18.

Then, 2 mL of trifluoroacetic acid was added to the drained polymer, and the excess trifluoroacetic acid was blown off after being gently shaken at room temperature for about 2 hours. The obtained viscous liquid was dissolved in 0.5 mL of methanol, and then 45 mL of ice-cold ether was added to precipitate a white precipitate. The dissolution-precipitation process was repeated three times to obtain an amphiphilic oxazoline blend polymer with side chain amino groups. The deprotected polymer was dissolved again in 5 mL of ultrapure water, filtered and freeze-dried for the next biological activity test.

Example 4 Synthesis of 2-(aminomethyl)oxazoline and 2-(naphthylmethyl)oxazoline polymer blends

The experimental method is the same as that of Example 3, except that the hydrophobic monomer is replaced by 2-(naphthylmethyl)oxazoline instead of 2-(isobutyl)oxazoline. After the polymerization reaction is completed, the mixture is cooled to room temperature, and cold petroleum ether (45 mL) is poured into the reaction mixture. The precipitated white floccules are collected by centrifugation, dried in a gas stream, and redissolved in tetrahydrofuran (1.5 mL), and then a large amount of cold petroleum ether is added for precipitation. This dissolution-precipitation process is repeated three times to obtain 78.2 mg (yield 95%) of a copolymer of oxazoline with protected side chain amino groups.

The molecular weight Mn of the polymer obtained by MeOTf-initiated polymerization was determined by gel permeation chromatography (GPC) to be 4290 and the molecular weight distribution PDI (Mw/Mn) to be 1.17.

Then add 2 mL of trifluoroacetic acid to the drained polymer, gently shake it at room temperature for about 2 hours, blow off the excess trifluoroacetic acid, and dissolve the resulting viscous liquid in 0.5 mL of methanol, then add 45 mL of ice-cold ether to precipitate a white precipitate, and repeat the dissolution-precipitation process three times to obtain an oxazoline homopolymer with a side chain amino group. The deprotected polymer is dissolved again in 5 mL of ultrapure water, filtered and freeze-dried for the next biological activity test.

Example 5 Synthesis of 2-(aminomethyl)oxazoline and 2-(naphthylmethyl)oxazoline block copolymer

The experimental method is the same as that of Example 4, except that, after the reaction of N-Boc-2-(aminomethyl)oxazoline monomer is completed, the hydrophobic monomer 2-(naphthylmethyl)oxazoline is added, and after the polymerization reaction of the hydrophobic monomer is completed, the mixture is cooled to room temperature, and cold petroleum ether (45 mL) is poured into the reaction mixture. The precipitated white floccules are collected by centrifugation, dried in an air stream, and redissolved in tetrahydrofuran (1.5 mL), and then a large amount of cold petroleum ether is added for precipitation. This dissolution-precipitation process is repeated three times to obtain 74.1 mg (yield 90%) of a block polymer of oxazoline with protected side chain amino groups.

The molecular weight Mn of the polymer obtained by MeOTf-initiated polymerization was identified by gel permeation chromatography (GPC) to be 4300 and the molecular weight distribution PDI (Mw/Mn) to be 1.23.

Then add 2 mL of trifluoroacetic acid to the drained polymer, gently shake it at room temperature for about 2 hours, blow off the excess trifluoroacetic acid, and dissolve the resulting viscous liquid in 0.5 mL of methanol, then add 45 mL of ice-cold ether to precipitate a white precipitate, and repeat the dissolution-precipitation process three times to obtain an oxazoline homopolymer with a side chain amino group. The deprotected polymer is dissolved again in 5 mL of ultrapure water, filtered and freeze-dried for the next biological activity test.

Example 6 Synthesis of an amphiphilic oxazoline polymer library with thiol-functionalized side-chain amino groups

The experimental method is the same as that in Example 3, except that the hydrophobic monomer is replaced by 2-(butyloxazoline) 2-(isobutyl)oxazoline, and the polymerization reaction is carried out by adjusting the ratio of different oxazoline monomers (the ratio is from 90% of N-Boc-2-(aminomethyl)oxazoline monomer + 10% of 2-(butyl)oxazoline to 30% of N-Boc-2-(aminomethyl)oxazoline monomer + 70% of 2-butyloxazoline); after the polymerization reaction, 20 mg of 3-(tritylthio)propionic acid, 13 mg of N,N-diisopropylethylamine and 12 mg of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride are added to continue the reaction for 12 h, then cooled to room temperature, and the reaction mixture is poured into cold petroleum ether (45 mL), and the precipitated white floccules are collected by centrifugation, dried in an air stream, and redissolved in tetrahydrofuran (1.5 mL), and a large amount of cold petroleum ether is added to precipitate. This dissolution-precipitation process was repeated three times to obtain a series of thiol-functionalized oxazoline copolymers with different hydrophilic-hydrophobic ratios (yield 85%-96%).

Then, the polymer was added with 2 mL of trifluoroacetic acid and 5% (v/v) triethylsilane to the dried polymer, stirred at room temperature overnight, and then the excess trifluoroacetic acid was blown off with nitrogen. The viscous liquid was dissolved in 0.5 mL of methanol, and then 45 mL of ice-cold ether was added to precipitate a white precipitate. The dissolution-precipitation process was repeated three times to obtain the oxazoline polymer library with side chain amino groups after thiol functionalization. The deprotected polymer was dissolved again with 5 mL of ultrapure water, filtered and freeze-dried for the next biological activity test.

It should be understood that the oxazoline monomer with protected amino groups in the side chain in the embodiment can successfully prepare an oxazoline polymer with amino groups in the side chain by using methyl trifluoromethanesulfonate as an initiator and under the other polymerization conditions described, which breaks the traditional perception that methyl trifluoromethanesulfonate is not suitable as an initiator for the polymerization of oxazoline monomers with protected amino groups in the side chain.

Example 7 Application of Oxazoline Polymers and Derivatives with Side Chain Amino Groups as Solution Antibacterial Materials

The minimum inhibitory concentration (MIC) test adopts the following method: bacteria are cultured overnight in a shaker at 37°C at 150 rpm using LB liquid medium (Luria-Bertani Broth), the cultured bacterial cells are collected by centrifugation and redispersed in MH (Mueller-Hinton Broth) medium, and the absorbance at 600nm ( _OD600 ) is read using an ELISA reader (when _OD600 = 1, the concentration of Staphylococcus aureus is approximately 1.5× ¹⁰⁹ CFU/mL). The bacterial solution is diluted to 2× ¹⁰⁵ CFU/mL with MH medium for later use. The polymer is diluted with MH medium in a 96-well plate, with a concentration range of 400 to 3.13 μg/mL. Then 50 μL of the diluted bacterial solution is added to each well, so that the total volume of the bacterial solution and the polymer is 100 μL, and the solution is gently shaken for 10 seconds, and then cultured in a 37°C mold incubator for 9 hours. Then, the OD ₆₀₀ was read using a microplate reader. In the same 96-well plate, 4 wells were added with only MH medium as negative control, and 4 wells were added with MH medium and bacterial solution (without polymer) as positive control. Two parallel samples were tested each time, and the test was repeated twice at different times. The percentage of bacterial growth in each well was calculated using the formula The calculated data is then plotted as a line graph, and the MIC value is the lowest concentration of the polymer that inhibits bacterial growth.

The polymers were tested for their minimum inhibitory concentrations against a variety of bacteria, including methicillin-resistant Staphylococcus aureus USA300, methicillin-resistant Staphylococcus aureus Mu50, Bacillus subtilis BR-151, Escherichia coli JM109, Pseudomonas aeruginosa ATCC ₉₀ 27, multidrug-resistant Pseudomonas aeruginosa ATCC ₁₅ 442, Pseudomonas aeruginosa O1 naturally resistant to sulfamethoxazole and tetracycline, and Acinetobacter baumannii ATCC BAA-747. The minimum inhibitory concentrations of the 2-aminomethyl oxazoline homopolymer prepared in Example 1 against the positive bacteria Staphylococcusaureus USA300, Staphylococcus aureus Mu50 and Bacillus subtilis BR-151 were 12.5 μg/mL, 12.5 μg/mL and 3.13 μg/mL, respectively; the minimum inhibitory concentrations of the guanidine-functionalized 4-aminopropyl oxazoline homopolymer prepared in Example 2 against the positive bacteria Staphylococcus aureus USA300, Staphylococcus aureusMu50 and Bacillus subtilis BR-151 were 100 μg/mL, 100 μg/mL and 6.25 μg/mL, respectively; the side chain amino oxazoline polymer prepared in Example 3 against the negative bacteria Pseudomonas aeruginosa ATCC15442, Pseudomonas aeruginosa ATCC15442, The minimum inhibitory concentrations of ₉₀ 27 and Pseudomonas aeruginosaO1 were both 3.13μg/mL; the minimum inhibitory concentrations of negative bacteria Acinetobacter baumanniiATCC BAA-747 and Escherichia coli JM109 were 12.5μg/mL and 6.25μg/mL, respectively. The MIC results showed that the oxazoline polymers with side chain amino groups and their guanidinized derivatives had strong antibacterial activity.

Example 8 Application of Oxazoline Polymers and Derivatives with Side Chain Amino Groups as Solution Antifungal Materials

The minimum inhibitory concentration (MFC) of the guanidine-functionalized oxazoline homopolymer prepared in Example 2 against Candida albicans K1 (C.albicansK1), Cryptococcus neoformans H99 (C.neoformans H99) and Cryptococcus neoformans JEC21 (C.neoformans JEC21) was 6.25 μg/mL (C.albicans K1), 3.13 μg/mL (C.neoformans H99) and 0.78 μg/mL (C.neoformans JEC21); the minimum inhibitory concentration (MFC) of the 2-aminomethyloxazoline and 2-naphthylmethyloxazoline polymer blend prepared in Example 4 against Candida albicans K1, Cryptococcus neoformans H99 and Cryptococcus neoformans JEC21 was 6.25 μg/mL (C.albicans K1), 3.13 μg/mL (C.neoformans H99) and 0.78 μg/mL (C. neoformans JEC21). The MFC results obtained proved that the oxazoline polymers and derivatives with side chain amino groups have strong antifungal activity.

Example 9 Application of Oxazoline Polymers with Side Chain Amino Groups as Surface Coating Antibacterial Materials

The polymer synthesis method is the same as that in Example 6, except that the deprotected thiol-terminated oxazoline polymer is grafted onto the gold sheet surface. The surface sterilization test adopts the following method: the bacteria are cultured overnight in a shaker at 37°C at 150 rpm using LB liquid culture medium (Luria-BertaniBroth). After the culture is completed, 7.5 mL of bacterial solution is taken out from the conical flask and centrifuged at 4000 rpm for 5 min to collect the bacteria, and then re-dispersed into PBS and re-centrifuged. The PBS-dispersed bacterial solution is centrifuged three times and then the bacterial solution is collected. The absorbance at 600 nm (OD ₆₀₀ ) is read using an ELISA reader to quantify the number of colonies. The bacterial solution is diluted with PBS to 1×10 ⁵ CFU/mL for later use. The prepared polymer antibacterial surface is placed in a 24-well plate, and PBS is used as a control. 80 μL of the bacterial solution of the above concentration was added to the surface of the polymer gold sheet, of which 80 μL of the bacterial solution was directly added to the well plate as a blank control, PBS was added to the blank well plate to control humidity, and it was cultured in a 37°C mold incubator for 2.5 hours. The well plate was taken out, 1920 μL of PBS was added to the well plate for dilution, ultrasonic treatment was performed for 3 minutes, and the mixture was mixed under a mixer for 2 minutes. 30 μL was taken out with a pipette and applied to the LB agar medium, and then cultured in a 37°C mold incubator. After counting the colonies, the surface antibacterial activity analysis was performed. The experimental group was recorded as C _sample , and the blank control was recorded as C _blank . The antibacterial activity (bacterial killing rate) of the substrate surface was calculated by the following formula:

The surface sterilization of oxazoline polymer blends with thiol functionalized side chain amino groups (preferably 90% N-Boc-2-(aminomethyl)oxazoline + 10% 2-(butyl)oxazoline) against Methicillin-resistant Staphylococcus aureus (MRSA) was tested. The experimental results show that the surface sterilization rate of this blended oxazoline polymer against MRSA can reach 99.9%, which has excellent surface sterilization efficacy.

Example 10 Application of Oxazoline Polymers with Side Chain Amino Groups as Cell Adhesion Materials

The polymer prepared in Example 6 was grafted onto the surface of a glass substrate. The specific method is as follows: 3-aminopropyltriethoxysilane was used as a glass surface amino modifier to modify the cleaned surface-activated glass slide, and then PEG was used to modify the amino-modified glass slide, and finally the amino acid polymer and the positive control peptide (RGD) were grafted. The cells were collected in a centrifuge tube by trypsin digestion, and the cell density was adjusted to 8×10 ⁴ cells/mL; the cells were inoculated into the holes on the surface of the amino acid polymer; the polymer surface was placed in a culture dish and cultured in a 37°C incubator. After the cells were incubated for 2 hours, the adhesion, spreading and aggregation of the cells on the polymer surface were observed under an inverted microscope; then the polymer surface with cells was immersed in the culture medium and continued to be cultured for 24 to 48 hours, and the morphology of cell adhesion and growth on the amino acid polymer surface was observed using an inverted fluorescence microscope in multiple areas, and the coverage area (%) of the cell surface was calculated. The experimental results show that on the glass surface grafted with oxazoline polymer, mouse embryonic fibroblasts (NIH 3T3) showed different adhesion effects in 48 hours. The preferred polymer is 40% N-Boc-2-(aminomethyl)oxazoline + 60% 2-(butyl)oxazoline. The polymer showed a similar cell adhesion effect to the positive control RGD. At the same time, the number of cells grown on the surface grafted with the polymer was 75% of the number of cells on the positive control RGD surface. Cell adhesion is a key step in the interaction between cells and materials in tissue engineering. Only after adhesion can cells carry out a series of behaviors such as proliferation, migration, and differentiation. Therefore, supporting cell adhesion is an essential property of biomaterials in tissue engineering applications.

Example 11 Application of Oxazoline Polymers with Side Chain Amino Groups as Antitumor Materials

The cytotoxicity test (MTT cell proliferation assay) was performed as follows: NCI-H460 cells, U87 cells, and B16 cells at a density of 3×10 ⁴ were inoculated into 96-well plates, with a volume of 100 μL per well. The cells were cultured at 37°C for 24 hours. After removing the old culture medium, culture medium containing different concentrations of amino acid polymers was added, and three replicate wells were set for each concentration. After culturing the cells at 37°C for 24 hours, 10 μL of MTT solution (5 mg/mL, prepared in PBS) was added to each well, and the incubation continued for 4 hours, and the culture was terminated. The culture supernatant in the well was carefully aspirated, and DMSO (150 μL) was added to each well. The wells were shaken on a shaker for 10 minutes to fully dissolve the crystals. On the same 96-well plate, cells without any amino acid polymer treatment were included as a control group, as well as a blank group without inoculated cells and only DMSO. The wavelength of 570 nm was selected, and the light absorption value (OD value) of each well was measured on a microplate reader, and the cell survival rate was calculated: % cell survival = (OD ^polymer -OD ^blank )/(OD ^control -OD ^blank ) × 100. On this basis, a curve of cell survival rate versus amino acid polymer concentration was drawn, and the minimum amino acid concentration that caused 50% mammalian cell death (IC ₅₀ ) was obtained from the curve.

The cytotoxicity of the oxazoline blend polymer with side chain amino groups prepared in Example 3 (the ratio was from 40% N-Boc-2-(aminomethyl)oxazoline to 60% 2-(isobutyl)oxazoline) on various tumor cells (NCI-H460 lung cancer cells, U87 glioma cells, B16 melanoma cells) was tested. The experimental results showed that the IC ₅₀ of the oxazoline polymer against NCI-H460 lung cancer cells was 25 μg/mL, showing a good anti-tumor effect.

Example 12 Application of Oxazoline Polymers with Side Chain Amino Groups as Self-Assembly Materials

The oxazoline block copolymer with side chain amino groups prepared in Example 5 is preferred. The preparation of the polymer self-assembly structure is carried out by the following method: 1 mg of the deprotected oxazoline polymer is dissolved in a corresponding volume of ultrapure water to prepare a 0.2 mg/mL or 0.5 mg/mL solution, and the solution is stirred at a medium speed of 390 rpm for 2 hours, and then allowed to stand for 12 hours. The self-assembly solution is filtered using a 0.8 μm filter head and DLS test is performed.

The particle size and dispersibility of the self-assembled samples were tested by dynamic light scattering (DLS). The samples were placed in PS cuvettes, and the volume of each test sample was about 1.5 mL. Each sample was tested three times, the test temperature was 25 ° C, and the test angle was set to 90 degrees. Data processing used cumulative analysis of experimental correlation functions and the Stokes-Einstein equation to calculate the diffusion coefficient.

The results of DLS experiments show that the particle size of the self-assembled structure formed by oxazoline polymer in water is 50-100nm, and the dispersibility PD is 0.2-0.4.

Example 13 Application of Oxazoline Polymers with Side Chain Amino Groups as Drug Delivery Materials

The oxazoline block copolymer with side chain amino groups prepared in Example 5 is preferably prepared as a drug delivery material by the following method: the preferred oxazoline block copolymer polymer (40 mg/mL) and amphotericin B (10 mg/mL) are dissolved in DMSO, 200 μL of the polymer solution is added dropwise (1 drop/2s) to ultrapure water stirred (360r-390r), stirred for 2h in the dark, allowed to stand in the dark for 8h, and filtered with a 0.8μm filter. The solution is dialyzed for 4h with a 3500 molecular weight dialysis bag, and the liquid (10% DMSO in ultrapure water) is changed every 30min, and the resulting liquid is stored at 4°C for a long term.

The results of DLS experiments show that the particle size of the self-assembled structure formed in water after the oxazoline polymer with side chain amino groups encapsulates the drug amphotericin B is 50-100nm, and the dispersibility PD is 0.2-0.4.

The hemolytic and antifungal activities of the material after encapsulating amphotericin B were tested and it was found that the hemolytic activity of the material after encapsulating amphotericin B on human mammalian erythrocytes was HC ₅₀ >200μg/mL, and the antifungal activity against the fungus C.albicans K1 was MFC=12.5μg/mL; in comparison, the hemolytic activity of the drug amphotericin B alone on human mammalian erythrocytes was HC ₅₀ =15.6μg/mL, and the antifungal activity against the fungus C.albicans K1 was MFC=1.56μg/mL; the experimental results showed that the oxazoline polymer with side chain amino groups maintained a stable self-assembly structure as a drug delivery material, while reducing the hemolytic toxicity of the drug amphotericin B.

Example 14 Application of Oxazoline Polymers with Side Chain Amino Groups as Drug-Synergic Antibacterial Materials

The oxazoline polymer with a side chain amino group prepared by Example 3 is preferred. The oxazoline polymer is used for the synergistic antibacterial test by the following method: the bacteria are dispersed in 10mL LB medium, the medium is placed in a shaking table at 37°C, and cultured at 150rpm for 10-11h. The bacterial culture medium solution obtained by overnight culture is centrifuged at 4000rpm, and after the supernatant obtained by centrifugation is poured off, 5mL MH medium is added to the bacteria obtained by centrifugation, and the bacteria are re-dispersed in MH medium by shaking. The OD ₆₀₀ value is read with an ELISA instrument, and then the bacterial concentration is determined to be 5×10 ⁵ CFU/mL by dilution with MH medium. The polymer solution is diluted to an appropriate concentration by a two-fold stepwise dilution method in a 96-well plate, and the volume of the polymer solution in each well is 40μL. The antibiotic solution is diluted horizontally to an appropriate concentration by a two-fold stepwise dilution method in another 96-well plate, and 40μL of the antibiotic solution is transferred row by row to a 96-well test plate. Then take 20μL of bacterial solution and add it to the 96-well test plate, so that the final concentration of the bacterial solution is 1×10 ⁵ CFU/mL, the final concentration of polymer and antibiotic is 200μg/mL-1.56μg/mL, the wells with 100μL MH medium are negative controls, and the wells with 100μL bacterial solution with a bacterial concentration of 1×10 ⁵ CFU/mL are positive controls. Place the 96-well plate horizontally on the table and shake it gently for 10 seconds, then place it in a 37℃ mold incubator for static culture. After 9 hours, read the OD ₆₀₀ with a microplate reader and calculate the bacterial growth rate:

% bacterial growth = (OD ^{experimental group} - OD ^{negative control} ) / (OD ^{positive control -} OD ^{negative control} ) × 100

The MIC (Minimum inhibition concentration) value is the minimum concentration of the polymer that inhibits bacterial growth. The FICI (Fractional Inhibitory Concentration Index) value characterizes the antibacterial effect of the combination of two substances at different concentrations, and calculates the fractional inhibition concentration index:

FICI = (MIC ^{polymer combination} /MIC ^{polymer alone} ) + (MIC ^{antibiotic combination} /MIC ^{antibiotic alone} )

On this basis, FICI ≤ 0.5 indicates that the two substances have a synergistic effect.

The synergistic antibacterial activity of the oxazoline polymer prepared in Example 3 and the antibiotic rifampicin against a variety of Gram-negative bacteria (including Pseudomonas aeruginosa P.aeruginosa O1; Acinetobacter baumannii A.baumanniiATCCBAA747; Escherichia coli E.coli ATCCBAA747) was tested. The experimental results showed that the FICI of the oxazoline polymer prepared in Example 3 combined with rifampicin against bacteria P.aeruginosa O1 was 0.51; the FICI against bacteria baumanniiATCCBAA747 was 0.25, and the FICI against bacteria E.coli ATCCBAA747 was 0.37, indicating that the oxazoline polymer with side chain amino groups and rifampicin have excellent synergistic antibacterial effects against Acinetobacter baumannii and Escherichia coli, and have an additive antibacterial effect against Pseudomonas aeruginosa.

Example 15 Synthesis of Oxazoline Monomer with Side Chain Hydroxyl

Tert-butoxyacetic acid (2 g, 15.1 mmol) was dissolved in 50 mL of dichloromethane. EDCI (4.6 g, 15.1 mmol), HOBT (3.3 g, 15.1 mmol), and N,N-2-isopropylethylamine (3.9 g, 30.2 mmol) were added in turn under an ice bath. After stirring for 30 minutes, 2-chloroethylamine hydrochloride (2.64 g, 22.6 mmol) was added. After stirring at room temperature for 8 hours, the reaction mixture was washed twice with 30 mL of deionized water and 30 mL of 5% citric acid aqueous solution, respectively. The organic phase was collected and dried over anhydrous magnesium sulfate. The organic phase was concentrated and purified by silica gel column chromatography to obtain an intermediate (1.9 g, yield 65%).

In a dry single-mouth bottle, sodium hydroxide (341 mg, 8.5 mmol) was dissolved in 35 mL of ethanol, and then the intermediate (1.5 g, 7.7 mmol) was added, and heated to reflux under nitrogen protection, and the reaction was carried out for 2 h. The reaction solution was concentrated, and 30 mL of dichloromethane was added to dissolve, and washed twice with 15 mL of deionized water, and finally purified by reduced pressure distillation to obtain O-tert-butyl protected hydroxyoxazoline monomer (850 mg, yield 70%). ¹ H NMR (400 MHz, CDCl ₃ ): δ4.27 (t, J＝9.6, 2H), 4.07 (s, 1H), 3.85 (t, J＝9.6, 2H), 1.23 (s, 9H).

It should be understood that the hydroxyoxazoline monomers with different carbon numbers in the side chains and their synthesis are as shown above. The raw material tert-butoxyacetic acid is replaced with tert-butoxypropionic acid or tert-butoxybutyric acid, and the hydroxyoxazoline monomers with different carbon numbers in the side chains can be prepared according to the described synthesis steps, which are not described in detail here.

Example 16 Synthesis of Oxazoline Homopolymers with Side Chain Hydroxyl Groups

The experimental method is the same as in Example 1, except that the N-Boc-2-(aminomethyl)oxazoline monomer is replaced with the hydroxyoxazoline monomer prepared in Example 15. After the polymerization reaction is completed, the mixture is cooled to room temperature, and cold petroleum ether (45 mL) is poured into the reaction mixture. The precipitated white floccules are collected by centrifugation, dried in an air stream, and redissolved in tetrahydrofuran (1.5 mL), and then a large amount of cold petroleum ether is added for precipitation. This dissolution-precipitation process is repeated three times to obtain 52.2 mg (yield 83%) of the oxazoline polymer with protected side chain hydroxyl groups.

The molecular weight Mn of the polymer obtained by MeOTf-initiated polymerization was determined by gel permeation chromatography (GPC) to be 2980 and the molecular weight distribution PDI (Mw/Mn) to be 1.14.

Then add 2 mL of trifluoroacetic acid to the drained polymer, gently shake it at room temperature for about 2 hours, blow off the excess trifluoroacetic acid, and dissolve the resulting viscous liquid in 0.5 mL of methanol, then add 45 mL of ice-cold ether to precipitate a white precipitate, and repeat the dissolution-precipitation process three times to obtain an oxazoline homopolymer with side chain hydroxyl groups. The deprotected polymer is dissolved again in 5 mL of ultrapure water, filtered and freeze-dried for the next biological activity test.

Example 17 Application of 3-(triphenylmercapto)propyl bromide-initiated hydroxyoxazoline monomer homopolymerization as surface antifouling material

The polymer synthesis method is the same as Example 16, except that 3-(triphenylmercapto) propyl bromide is used as an initiator to replace trifluoromethanesulfonic acid methyl ester. After the polymerization reaction is finished, it is cooled to room temperature, cold petroleum ether (45mL) is poured into the above-mentioned reaction mixture, and the white floccules separated out are collected by centrifugation, dried in an air stream, and redissolved in tetrahydrofuran (1.5mL), and then a large amount of cold petroleum ether is added to precipitate. The obtained polymer is copolymerized after two or more monomers are mixed in a set ratio by three times of dissolution-precipitation process purification. The polymer drained is added with 2mL trifluoroacetic acid and 5% (v/v) triethylsilane, and the excess trifluoroacetic acid is blown off after gently shaking overnight at room temperature. The viscous liquid obtained is dissolved in 0.5mL methanol, and 45mL frozen ether is added to separate out white precipitate, and the dissolution-precipitation process is repeated three times to obtain the oxazoline homopolymer of the side chain hydroxyl and the terminal thiol deprotection. The deprotected polymer is dissolved with 5mL ultrapure water again, and is used for the next biological activity test after filtering and freeze-drying.

The deprotected oxazoline polymer with side chain hydroxyl groups was grafted onto the surface of the gold sheet. The surface antifouling test was performed using the following method. Escherichia coli 25922 was cultured in LB liquid culture medium (Luria-Bertani Broth) at 37°C in a shaker at 150 rpm overnight. After the culture was completed, 7.5 mL of bacterial solution was taken out from the conical flask and centrifuged at 4000 rpm for 5 minutes to collect the bacteria, and then redispersed into PBS and centrifuged again. The PBS-dispersed bacterial solution was centrifuged three times and then the bacterial solution was collected. The absorbance at 600 nm (OD ₆₀₀ ) was read using an ELISA reader to quantify the number of colonies. The bacterial solution was diluted with PBS to 1×10 ⁶ CFU/mL for later use. The prepared polymer antifouling surface was placed in a 24-well plate, and 100 μL of 2 mg/mL polymer solution was added to the gold sheet surface, and PBS was used as a control. After overnight, it was washed alternately with deionized water and ethanol twice and dried with nitrogen. Place the plate in a new 24-well plate, add 1 mL of the diluted bacterial solution to each well, incubate for 1 day, wash with PBS several times, and then stain with LIVE/DEAD.

The adhesion and growth state of bacteria on the polymer surface were observed under an inverted microscope; the experimental results showed that no obvious bacteria were observed on the glass surface of the grafted oxazoline polymer, while a large number of bacteria were observed on the surface without the grafted polymer. Therefore, the hydroxyoxazoline homopolymer exhibited the function of an excellent surface antifouling material.

Example 18 Application of Oxazoline Homopolymers with Side Chain Hydroxyl Groups as Cell Cryopreservation Protective Materials

Cell freezing and recovery experiments were performed as follows. Different CPA formulations were prepared using cell culture medium containing 20% fetal bovine serum (FBS) (pure culture medium as blank control, culture medium + 4% betaine, culture medium + 4% betaine + 0.2% oxazoline polymer, culture medium + 10% DMSO as positive control). After sterilization using a syringe filter device (0.22 μm, Titan), 0.5 mL of CPA solution with 1.0×10 ⁶ CFU/mL NIH3T3 cells was added to a cryovial. Each sample was incubated at 37°C for 1 h and then transferred to a program cooling box to achieve a stepwise freezing cooling rate of approximately -1°C/min, and the program cooling box was transferred to an 80°C refrigerator for freezing. In order to test the activity of NIH3T3 cells after being frozen by the above method, after the programmed cooling box was transferred to a -80°C refrigerator for 12 hours, the cryovial containing NIH3T3 cells was taken out and quickly thawed in a 37°C water bath, and then the NIH3T3 cells were collected by centrifugation at 1200 rpm for 4 minutes using a low-speed centrifuge. Finally, the supernatant was removed, and fresh culture medium was added to redisperse the cells in the culture dish. The cells were transferred to a _CO2 incubator and cultured in an environment of 37°C and 5% _CO2 .

The oxazoline polymer with a side chain hydroxyl group prepared in Example 16 is preferred. The effect of the polymer on the activity of cells after freezing and recovery is observed. The four cell culture media prepared are pure culture medium, culture medium + 10% DMSO, culture medium + 4% betaine, and culture medium + 4% betaine + 0.2% oxazoline polymer. After the cell freezing and recovery steps described above, the recovered NIH3T3 cells are placed in a _CO2 incubator and cultured at 37°C and 5% _CO2 for 12 hours. The number of cell adhesions and the morphology of cell adhesion are observed using random fields under an inverted microscope. The experimental results show that the NIH3T3 cells that were frozen in pure culture medium and culture medium + 4% betaine and then revived basically did not spread and grow on the culture dish, and the cell viability was negligible, which also showed that pure culture medium and betaine could not play a protective role in the process of cell cryopreservation; NIH3T3 cells that were frozen and revived in the traditional DMSO-added cryopreservation solution could be observed to spread a lot on the culture dish; and after being frozen and revived in the cell cryopreservation solution with the addition of oxazoline polymer, a large number of NIH3T3 cells with good spreading and growth status could be observed on the culture dish. According to the counting method, the number of cell spreading reached 95% of the NIH3T3 cells that were frozen and revived in the traditional DMSO-added cryopreservation solution. The experimental results show that the hydroxyoxazoline homopolymer exhibits the performance of an excellent cell cryopreservation protection material.

In addition, it should be understood that after reading the above teachings of the present invention, those skilled in the art may make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to this application.

Claims (17)

1. An oxazoline polymer, characterized in that it comprises one or more repeating units represented by formula _E1 and/or formula _E2 , in, L ₁ and L' ₁ are each independently absent, -CHR ₁ -; Each R ₁ and each R' ₁ are independently selected from the following substituted or unsubstituted groups: H, C1-C15 alkyl, C1-C15 alkylamino, C6-C15 aryl, 5-15 membered heteroaryl, 5-12 membered heterocyclyl, wherein the substitution refers to substitution by one or more groups selected from the following group: halogen, hydroxyl, amino, guanidino, -CO-NH ₂ , -COOH, Ph-, -PhOH, C1-C15 alkyl, C1-C15 alkoxy, C3-C15 cycloalkyl, C4-C12 cycloalkenyl; Ra and Rb are each independently selected from the group consisting of substituted or unsubstituted hydrogen, C1-C15 alkyl, C1-C15 alkylamino, C1-C15 alkylhydroxy, C3-C12 cycloalkyl, 5-12 membered heterocyclyl, C6 aryl, 5-12 membered heteroaryl, wherein the substitution refers to substitution by one or more groups selected from the group consisting of halogen, hydroxy, amino, guanidino, -CO-NH ₂ , -COOH, Ph-, -PhOH, C1-C15 alkyl, C1-C15 alkoxy, C3-C15 cycloalkyl, C4-C12 cycloalkenyl; Or in formula E1, Ra together with O and its adjacent C atom forms a substituted or unsubstituted 3-12 membered heterocyclic group containing at least 1 O heteroatom and 0-2 heteroatoms selected from N and S; Or in formula E2, Ra and Rb together with the adjacent N atom form a substituted or unsubstituted 3-12 membered heterocyclic group, the 3-12 membered heterocyclic group contains at least 1 N heteroatom and 0-2 heteroatoms selected from O and S; or Ra together with N and its adjacent C atom form a substituted or unsubstituted 3-12 membered heterocyclic group, the 3-12 membered heterocyclic group contains at least 1 N heteroatom and 0-2 heteroatoms selected from O and S, wherein Rb is selected from the following substituted or unsubstituted groups: hydrogen, C1-C15 alkyl, C1-C15 alkylamino, C1-C15 alkylhydroxy, C3-C12 cycloalkyl, 5-12 membered heterocyclic group, C6 aryl, 5-12 membered heteroaryl, wherein the substitution refers to substitution by one or more groups selected from the following groups: halogen, hydroxyl, amino, guanidinyl, -CO-NH ₂ , -COOH, Ph-, -PhOH, C1-C15 alkyl, C1-C15 alkoxy, C3-C15 cycloalkyl, C4-C12 cycloalkenyl; m is 1, 2, 3 or 4; m' is 1, 2, 3 or 4; q is an integer of 0, 1, 2, 3, 4, or 5; q' is an integer of 0, 1, 2, or 3; and m'+q'≤4; Wherein, for the substituted 3-12 membered heterocyclic group, the substitution refers to substitution by one or more groups selected from the following group: halogen, hydroxyl, amino, guanidino, -CO- _NH2 , -COOH, Ph-, glucosyl, C1-C15 alkoxy, C3-C15 cycloalkyl, C4-C12 cycloalkenyl. 2. oxazoline polymer as claimed in claim 1, is characterized in that, also comprises one or more in B and/or C repeating unit: in, _R2 is C1-C8 alkyl, C3-C8 cycloalkyl, C6-C12 aryl, C6-C12 arylalkyl; Ra is independently selected from the following group: substituted or unsubstituted: hydrogen, C1-C15 alkyl; L ₁ , R ₁ , m and q are as defined in claim 1 . 3. The oxazoline polymer according to claim 1, wherein the formula E ₂ has the structure shown in formula E' ₂ : in, Ring A is independently a substituted or unsubstituted 3-12 membered heterocyclic group; Wherein, the substitution refers to substitution by one or more groups selected from the group consisting of halogen, hydroxyl, amino, guanidinyl, -CO-NH ₂ , -COOH, Ph-, glucosyl, C1-C15 alkoxy, C3-C15 cycloalkyl, C4-C12 cycloalkenyl; The definitions of R' ₁ , m' and Rb are as described in claim 1 . 4. The oxazoline polymer according to claim 1 or 2, wherein the oxazoline polymer is an oxazoline polymer whose side chain contains amino, and has a structure as shown in Formula II: Wherein, n is an integer of 5-50000; 0%<x<100%; 0%≤y<100%; 0%≤z<100%; wherein x, y, and z are calculated by dividing the corresponding number of side chain repeating units by the total number of repeating units; m, m', R ₁ , R' ₁ , Ra and Rb are as defined in claim 1 ; R ₂ is as defined in claim 2 . 5. The oxazoline polymer according to claim 1 or 2, wherein the oxazoline polymer is an oxazoline polymer whose side chain contains a hydroxyl group, and has a structure as shown in Formula I: wherein m, R ₁ and _Ra are as defined in claim 1, and R ₂ is as defined in claim 2; n is an integer of 5-50000; 0%<x<100%; 0%≤y<100%; 0%≤z<100%; wherein x, y and z are calculated by dividing the corresponding number of side chain repeating units by the total number of repeating units. 6. The oxazoline polymer according to claim 1 or 2, wherein the oxazoline polymer is an oxazoline polymer whose side chain contains amino and hydroxyl, and has the structure shown in Formula III: Wherein, 0%＜w<100%; 0%≤x ₁ <100%;0%≤y<100%;0%≤z<100%; wherein w, x ₁ , y, z are calculated by dividing the corresponding number of repeating units by the total number of repeating units; m, m', R ₁ , R' ₁ , Ra and Rb are as defined in claim 1; R ₂ is as defined in claim 2; n is an integer from 5 to 50,000. 7. The oxazoline polymer according to claim 1 or 2, characterized in that the oxazoline polymer is an oxazoline polymer that contains amino and/or hydroxyl in a side chain, characterized in that it has the structure shown in IV-IX: Wherein, n, x, y, z, m, R ₁ and R ₂ are defined as in claim 4; wherein n, x, y, z, m, m', R ₁ , R' ₁ and R ₂ are as defined in claim 4; n, x, y, z, m, m', R ₁ , R' ₁ , R ₂ and Rb are as defined in claim 4, and ring A is as defined in claim 3; R ₆ is independently substituted or unsubstituted C1-C15 alkyl-NRaRb, substituted or unsubstituted 5-12 membered heterocyclyl; Wherein, the substitution refers to substitution by one or more groups selected from the group consisting of halogen, hydroxyl, amino, guanidinyl, -CO-NH ₂ , -COOH, Ph-, 5-12 membered heteroaryl, 5-12 membered heterocyclic group; n, x, y, z, m, R ₁ and R ₂ are as defined in claim 4; in, m, m', n, x, y, z, w, x ₁ , R ₁ , R' ₁ and R ₂ are as defined in claim 4; _R6 is independently substituted or unsubstituted C1-C15 alkyl-NRaRb, or substituted or unsubstituted 5-12 membered heterocyclyl. 8. A method for preparing an oxazoline polymer containing an amino group in a side chain, comprising the steps of: In an organic solvent, in the presence of an initiator and under heating conditions, polymerizing an oxazoline monomer represented by formula _E'2 and optionally a monomer of formula B' and/or formula C' to obtain an oxazoline polymer containing an amino group in the side chain; wherein R' ₁ , m', q', L ₁ ', R ₁ , m, q, L ₁ , Ra and Rb are as defined in claim 1; R ₂ is as defined in claim 2; The organic solvent is selected from the group consisting of DMAc, DMF, or a combination thereof; The initiator is selected from the group consisting of MeOTf, BzOTf, or a combination thereof. 9. An oxazoline monomer having a hydroxyl group in the side chain, characterized in that it has a structure as shown in Formula _E'1 : Wherein, R ₁ , m, q, L ₁ , and Ra are as defined in claim 1. 10. The oxazoline monomer as claimed in claim 9, wherein the side chain comprises a hydroxyl group, wherein the formula _E'1 has a structure as shown in the formula E" ₁ : Wherein, _P2 is a hydroxyl protecting group selected from: TMS, TBS, TBDPS, t-Bu; m, _R1 are defined as described in claim 1. 11. A method for preparing the oxazoline monomer having a hydroxyl group in the side chain as claimed in claim 10, characterized in that it comprises the steps of: In the formula, m, P ₂ , and R ₁ are defined as in claim 10; X is a leaving group selected from the group consisting of Br, Cl, I, OTs, and OMs; (2) reacting compound 2 with a base in a second inert solvent to obtain a monomer of formula E″ ₁ ; The base is selected from the group consisting of sodium hydroxide, potassium hydroxide, triethylamine, N,N-diisopropylethylamine, or a combination thereof; The second inert solvent is independently selected from the group consisting of methanol, ethanol, acetonitrile, or a combination thereof. 12. The method according to claim 11, further comprising the steps of: In the formula, R ₁ , P ₂ , X, and m are as defined in claim 11; (1) reacting compound 1 with H ₂ N(CH ₂ ) ₂ X in a first inert solvent to obtain compound 2; The first inert solvent is independently selected from the group consisting of DCM, DMF, THF, DMAc, or a combination thereof. 13. A method for preparing an oxazoline polymer having a hydroxyl group in a side chain, characterized in that the method comprises the following steps: In an inert solvent and inert gas protection, in the presence of an initiator and under heating conditions, an oxazoline monomer represented by formula _E'1 and optionally a monomer of formula B' and/or formula C' are polymerized to obtain an oxazoline polymer having a side chain hydroxyl group. wherein R ₁ , m, q, L ₁ , and Ra are as defined in claim 1; R ₂ is as defined in claim 2; The inert solvent is selected from the group consisting of DMAc, DMF, MeCN, PhCN, or a combination thereof; The initiator is selected from the group consisting of MeOTf, BzOTf, CH ₃ (CH ₂ ) ₅ Br, CH ₃ (CH ₂ ) ₅ OTs, or a combination thereof. 14. A method for preparing an oxazoline polymer having an amino group and a hydroxyl group in a side chain, comprising the following steps: In an organic solvent, in the presence of an initiator and under heating conditions, an oxazoline monomer represented by formula _E'2 and an oxazoline monomer represented by formula _E'1 , and optionally oxazoline monomers of other structures, are subjected to polymerization reaction to obtain an oxazoline polymer having an amino group and a hydroxyl group in the side chain; wherein R' ₁ , m', q', L ₁ ', R ₁ , m, q, L ₁ , Ra and Rb are as described in claim 1; The organic solvent is selected from the group consisting of DMAc, DMF, or a combination thereof; The initiator is selected from the group consisting of MeOTf, BzOTf, or a combination thereof. 15. Use of an oxazoline polymer having an amino group in the side chain prepared by the preparation method of claim 8, characterized in that it is used to prepare materials used in the fields of antibacterial, antifungal, antitumor, cell adhesion, drug synergy, drug delivery and self-assembly materials. 16. Use of an oxazoline polymer having a hydroxyl group in the side chain prepared by the preparation method of claim 13, characterized in that it is used to prepare products or preparations for surface antifouling and cell cryoprotection. 17. The purpose of an oxazoline polymer whose side chain prepared by the preparation method of claim 14 contains amino and hydroxyl, characterized in that it is used to prepare a material for having the function of an oxazoline polymer whose side chain contains amino and hydroxyl concurrently, wherein the function of an oxazoline polymer whose side chain contains amino and hydroxyl concurrently refers to being used for antibacterial, antifungal, antitumor, cell adhesion, drug synergy, drug delivery, self-assembly material, surface antifouling, and cell cryoprotection.