CN116370497B - A pet-specific wound care composite gel dressing and preparation method thereof - Google Patents

Abstract

The invention provides a special wound care composite antibacterial gel dressing for pets and a preparation method thereof, the special wound care composite gel dressing for pets comprises florfenicol and chitosan compound and has excellent antibacterial activity. Can effectively shorten the time required by wound healing and reduce secondary infection of wounds, and can be widely used for treating common wounds and infectious wounds of pets.

Description

A pet-specific wound care composite gel dressing and preparation method thereof

Technical Field

The invention relates to the technical field of veterinary drug preparation, in particular to a pet-specific wound care composite gel dressing and a preparation method thereof.

Background Art

The skin is the largest organ in the animal body, which has the functions of sensing external stimuli, regulating body temperature, and protecting tissues and organs. The skin is in direct contact with the outside world and is easily affected by external factors and damaged. Most skin injuries can recover on their own within a period of time, but in the case of large-area full-thickness skin defects, especially in the case of bacterial infection, it takes a long time to completely repair. Due to the long self-healing time and the long-term contact of the wound with the outside world, it may cause secondary bacterial or fungal infections, which may cause wounds. Severe ulcers may cause systemic infections, which not only prolongs the time required for the wound to heal, but also increases the pain of the animal and may even endanger the animal's life. The main function of wound dressings is to protect the wound surface, reduce the effects of external physical and chemical stimuli and pathogenic microorganisms on wound repair, and maintain the wound healing environment. Existing wound dressings are not ideal and need to be replaced regularly during use. They are very likely to cause secondary damage to the wound surface and interfere with the process of wound repair.

With the continuous deepening of wound dressing research, new dressing materials have been continuously developed. Among them, chitosan not only has good biocompatibility. It also has antibacterial, anti-inflammatory, hemostatic, analgesic, antipruritic, scar removal, wound healing promotion, moisture absorption and moisture retention. Due to the interaction between the positive charge in its molecules and the negative charge in the microbial cell membrane, it leads to the leakage of bacterial proteins and other cell components, making it have a good inhibitory effect on bacteria, yeast, fungi and other microorganisms, and is widely used in the preparation of wound dressings.

Florfenicol is a third-generation chloramphenicol broad-spectrum antibiotic for animals. It is widely used in clinical practice due to its rapid absorption after oral administration and intramuscular injection, wide distribution in the body, and long half-life. It can strongly interfere with the synthesis of bacterial proteins and has a strong inhibitory effect on a variety of Gram-positive bacteria, Gram-negative bacteria, as well as Rickettsia, spirochetes, mycoplasmas, etc.

As a new type of wound dressing, thermosensitive gel has the characteristics of tightly fitting but non-adhering to the wound compared with traditional dressings, thus avoiding secondary damage. It is in a sol-like state at room temperature and fills the wound, including irregular wound surfaces, after administration, and is converted into a gel. It adheres to the wound surface and can completely cover the wound surface, protecting it from external factors and maintaining the wound healing environment.

The purpose of the present invention is to provide a pet-specific wound care composite gel dressing and a preparation method thereof. Florfenicol is wrapped by combining the antibacterial activity of chitosan and the effect of inclusion, thereby improving the antibacterial activity of florfenicol, and at the same time combining the advantages of thermosensitive gel that can fit tightly and perfectly fill wounds, and developing it into a gel dressing with excellent antibacterial properties that can promote infectious wound repair and postoperative wound care.

Summary of the invention

To achieve the above object, the present invention provides the following solutions:

One of the technical solutions of the present invention: a pet-specific wound care composite gel dressing, comprising the following raw materials in parts by weight:

0.1-5 parts of florfenicol, 0.1-5 parts of chitosan, 0.1-5 parts of cross-linking agent, 20-50 parts of temperature-sensitive biomaterial, 0.1-10 parts of acetic acid, 1-10 parts of methanol, and 50-100 parts of water.

Furthermore, the pet-specific wound care composite gel dressing comprises the following raw materials in parts by mass: 0.3 parts of florfenicol, 1 part of chitosan, 0.1 parts of a cross-linking agent, 30 parts of a temperature-sensitive biomaterial, 0.1 parts of acetic acid, 4 parts of methanol, and 65 parts of water.

Furthermore, the cross-linking agent is one or more of sodium tripolyphosphate, formaldehyde, glutaraldehyde, and genipin.

Furthermore, the cross-linking agent is genipin.

Furthermore, the temperature-sensitive biomaterial includes one or more of poly (N-isopropylacrylamide) and poloxamer 407.

Furthermore, the temperature sensitive material is poloxamer 407.

The second technical solution of the present invention is to provide a method for preparing a pet-specific wound care composite gel dressing, comprising the following steps:

(1) adding chitosan to water according to a certain proportion, and adding acetic acid to dissolve the chitosan, thereby obtaining a solution 1;

(2) adding florfenicol to methanol in proportion, stirring evenly, and dissolving with ultrasonication to obtain solution 2;

(3) adding solution 2 dropwise to solution 1 and stirring evenly to obtain solution 3;

(4) adding a cross-linking agent to solution 3 in proportion, stirring for 2 h for cross-linking, and obtaining solution 4;

(5) Add the temperature-sensitive biomaterial to solution 4 in proportion, stir evenly, and make it swell to obtain the pet-specific wound care composite gel dressing. The composite gel dressing prepared by the method contains a composite of florfenicol and chitosan.

Furthermore, the dropping in step (3) is performed while stirring, and the stirring condition is 1500r/min.

Furthermore, the cross-linking temperature in step (4) is 50°C.

Furthermore, the swelling temperature in step (5) is 4° C. and the swelling time is 24 hours.

The third technical solution of the present invention: Application of a pet-specific wound care composite gel dressing in antibacterial, promoting infectious injury repair and postoperative care.

Compared with the prior art, the present invention has the following beneficial effects:

The present invention provides a wound care composite gel dressing for pets. The present invention combines the technical advantages of nano-encapsulation technology and thermosensitive gel technology to prepare two preparations, and uses florfenicol and chitosan together to obtain a wound care gel dressing with excellent antibacterial properties. In particular, florfenicol is encapsulated with chitosan, which not only enhances its antibacterial effect, but also prolongs the release time of the drug, which can effectively shorten the time required for wound healing, reduce secondary infection of the wound, and promote wound healing.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

FIG1 is a diagram showing the appearance of a pet-specific wound care composite gel dressing prepared in Example 1 of the present invention;

FIG2 is a scanning electron microscope image of the pet-specific wound care composite gel dressing prepared in Example 1 of the present invention;

FIG3 is a graph showing the particle size measurement results of the pet-specific wound care composite gel dressing prepared in Example 1 of the present invention;

FIG4 is a graph showing the Zeta potential measurement results of the pet-specific wound care composite gel dressing prepared in Example 1 of the present invention;

FIG5 is a diagram showing the antibacterial effect of the pet-specific wound care composite gel dressing prepared in Example 1 of the present invention;

Figure 6 shows representative images of wound surfaces of mice in different treatment groups;

Figure 7 shows the changes in wound area in different treatment groups.

DETAILED DESCRIPTION

Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

It should be understood that the terms described in the present invention are only for describing a particular embodiment and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and materials related to the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present application description and examples are exemplary only.

The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

The “parts” described in the following examples are all “parts by mass”.

The present invention will be further described below in conjunction with the embodiments.

Example 1

A pet-specific wound care composite gel dressing, composed of the following raw materials:

0.3 parts of florfenicol (original drug), 1 part of chitosan, 0.1 parts of genipin (cross-linking agent), 30 parts of poloxamer 407 (temperature-sensitive biomaterial), 0.1 parts of acetic acid, 4 parts of methanol, and 65 parts of deionized water.

The preparation method of the pet-specific wound care composite gel dressing comprises the following steps:

(1) adding chitosan to water according to a certain proportion, and adding acetic acid to dissolve the chitosan, thereby obtaining a solution 1;

(2) adding florfenicol to methanol according to a certain proportion, stirring evenly, and dissolving with ultrasonication to obtain solution 2;

(3) adding the solution 2 dropwise into the solution 1 while stirring at a high speed (1500 rpm) to obtain a solution 3;

(4) adding the cross-linking agent to solution 3 in proportion, stirring at 50°C with high speed (1500 rpm) for 2 h to allow chitosan to cross-link with the cross-linking agent, thereby obtaining solution 4;

(5) Add the temperature-sensitive biomaterial to solution 4 in proportion, stir evenly, seal the opening with plastic wrap and place in a 4°C refrigerator for 24 hours to allow it to fully swell, thereby obtaining the pet-specific wound care composite gel dressing. The composite gel dressing contains a complex of florfenicol and chitosan.

(6) Use the "inversion method" to detect its thermosensitivity. Take 5 mL of the prepared pet-specific wound care composite gel into a glass bottle, place it in a constant temperature water bath, and slowly increase the temperature from 20°C, increasing by 1°C every 5 minutes. After each 1°C increase, take it out and invert the glass bottle. The gel temperature of the gel is when the gel solution in the glass bottle does not flow.

Example 2

A pet-specific wound care composite gel dressing, composed of the following raw materials:

0.3 parts of florfenicol (original drug), 1 part of chitosan, 0.1 parts of formaldehyde (cross-linking agent), 30 parts of poloxamer 407 (temperature-sensitive biomaterial), 0.1 parts of acetic acid, 4 parts of methanol, and 65 parts of deionized water.

The preparation method of the pet-specific wound care composite gel dressing comprises the steps as in Example 1

Example 3

A pet-specific wound care composite gel dressing, composed of the following raw materials:

0.3 parts of florfenicol (original drug), 1 part of chitosan, 0.1 parts of formaldehyde (cross-linking agent), 30 parts of poly (N-isopropylacrylamide) (temperature-sensitive biomaterial), 0.1 parts of acetic acid, 4 parts of methanol, and 65 parts of deionized water.

The preparation method of the pet-specific wound care composite gel dressing comprises the steps as in Example 1

Example 4

A pet-specific wound care composite gel dressing, composed of the following raw materials:

0.3 parts of florfenicol (original drug), 1 part of chitosan, 0.1 parts of sodium tripolyphosphate (cross-linking agent), 30 parts of poly (N-isopropylacrylamide) (temperature-sensitive biomaterial), 0.1 parts of acetic acid, 4 parts of methanol, and 65 parts of deionized water.

The preparation method of the pet-specific wound care composite gel dressing comprises the steps as in Example 1

Example 5

A pet-specific wound care composite gel dressing, composed of the following raw materials:

0.3 parts of florfenicol (original drug), 1 part of chitosan, 0.1 parts of sodium tripolyphosphate (cross-linking agent), 30 parts of poloxamer 407 (temperature-sensitive biomaterial), 0.1 parts of acetic acid, 4 parts of methanol, and 65 parts of deionized water.

The preparation method of the pet-specific wound care composite gel dressing comprises the steps as in Example 1

Comparative Example 1

A pet-specific wound care composite gel dressing, composed of the following raw materials:

0.3 parts of florfenicol (original drug), 1 part of chitosan, 0.1 parts of genipin (cross-linking agent), 10 parts of poloxamer 407 (temperature-sensitive biomaterial), 0.1 parts of acetic acid, 4 parts of methanol, and 85 parts of deionized water.

The preparation method of the pet-specific wound care composite gel dressing comprises the following steps:

(1) adding chitosan to water according to a certain proportion, and adding acetic acid to dissolve the chitosan, thereby obtaining a solution 1;

(2) adding florfenicol to methanol according to a certain proportion, stirring evenly, and dissolving with ultrasonication to obtain solution 2;

(3) adding the solution 2 dropwise into the solution 1 while stirring at a high speed (1500 rpm) to obtain a solution 3;

(4) adding the cross-linking agent to solution 3 in proportion, stirring at 50°C with high speed (1500 rpm) for 2 h to allow chitosan to cross-link with the cross-linking agent, thereby obtaining solution 4;

(5) Add the temperature-sensitive biological material to solution 4 in proportion, stir evenly, seal the opening with plastic wrap and place in a refrigerator at 4° C. for 24 hours to allow it to fully swell to obtain the florfenicol composite antibacterial gel dressing for pets. The composite gel dressing contains a complex of florfenicol and chitosan.

(6) Use the "inversion method" to detect its thermosensitivity. Take 5 mL of the prepared pet-specific wound care composite gel into a glass bottle, place it in a constant temperature water bath, and slowly increase the temperature from 20°C, increasing by 1°C every 5 minutes. After each 1°C increase, take it out and invert the glass bottle. The gel temperature of the gel is when the gel solution in the glass bottle does not flow.

The gel prepared in this comparative example is not temperature-sensitive because the proportion of the temperature-sensitive biomaterial is too low.

Effect Example 1

(I) The hydrogel prepared in Example 1 was characterized, and the results are shown in Figures 1 to 4.

FIG1 is a schematic diagram of the appearance of a gel dressing prepared in Example 1 of the present invention;

As can be seen from FIG. 1 , the gel prepared in Example 1 of the present invention is in a blue-grey sol state (this is caused by the cross-linking of genipin in the gel with the amino groups in chitosan to produce a blue compound), and turns into a blue-grey solid gel when the temperature rises to 33° C.

The gel sample prepared in Example 1 of the present invention was freeze-dried and then adhered to a scanning electron microscope sample plate with conductive glue. It was sputtered with gold using an ion sputtering device, and then the structure of the sample was observed using a scanning electron microscope. The results are shown in FIG2 .

As can be seen from Figure 2, the hydrogel prepared in Example 1 of the present invention forms a three-dimensional grid pore structure with a pore size of about 5 to 35 μm, which is evenly distributed and can carry drugs well. In the process of tissue repair, it is beneficial to the transmission of nutrients and gas exchange, maintains a suitable wound healing environment, and promotes wound healing.

1 mL of the hydrogel prepared in Example 1 of the present invention was taken, diluted 100 times with deionized water, ultrasonicated for 30 min, and stored for later use. The particle size and Zeta potential were detected using a nanoparticle size and Zeta potential analyzer (DLS). The results are shown in Figures 3 and 4.

The particle size of the gel prepared in Example 1 of the present invention is 121.82±0.58nm (Figure 3). Due to the small particle size of the gel, the drug can be better delivered to the medication site through the tissue gap, thereby achieving the antibacterial effect and promoting tissue repair; the Zeta potential is -1.85±0.35mA (Figure 4), indicating that the surface charge is neutral and can be adsorbed on the bacterial surface to inhibit bacterial growth.

(II) Antimicrobial activity detection

200 μL of 10 ⁸ cfu/mL logarithmic phase Staphylococcus aureus was taken with a pipette and added to the MH agar medium plate, and evenly spread with a coating rod and allowed to stand for 3-5 min; 4 holes were made on the MH agar medium coated with the bacterial solution with a sterilized 200 μL yellow pipette tip, and 0.3% florfenicol chitosan composite antibacterial gel, 0.3% florfenicol solution, 1% chitosan gel, and sterile deionized water were added respectively, and the plate was placed in a 37°C constant temperature incubator. After overnight, the inhibition zone was measured and the size of the inhibition zone was compared. The results are shown in Figure 5 (1 is a pet-specific wound care composite gel dressing, 2 is a 0.3% florfenicol solution, 3 is a 1% chitosan gel, and 4 is sterile deionized water).

As can be seen from Figure 5, the antibacterial effect of the pet-specific wound care composite gel dressing is significantly enhanced compared with the same concentration of florfenicol solution and chitosan gel, indicating that the pet-specific wound care composite gel dressing has good antibacterial activity.

(III) Effect of pet-specific wound care composite gel dressing on the repair of infectious skin lesions in mice

Thirty-six healthy Kunming mice (18-22 g) were selected and anesthetized with ketamine hydrochloride (60 mg/kg body weight). After hair removal, a full-thickness skin defect with a diameter of 12 mm was formed on the back of the mice. After rinsing with saline, the wound was covered with 1×10 ⁸ CFU/mL of Staphylococcus aureus to make an infectious wound model. After 24 hours of infection, yellowish pus was observed on the wound and the edge of the wound, indicating that the model was successfully constructed. The mice were randomly divided into 4 groups by random drawing, with 9 mice in each group, and the control group did not receive any treatment. The remaining 3 groups were covered with pet-specific wound care composite gel dressings, 0.3% florfenicol solution and 1% chitosan gel, respectively, and the dressings were changed every 48 hours. The wound healing of the 4 groups of mice was observed on the 3rd, 7th and 14th days after treatment, and the wounds were photographed and recorded. The photos were imported into Image J software to measure the area of unhealed wounds.

As shown in Figures 6 and 7, as the treatment time prolonged, the wound area of all groups of mice continued to shrink, and the wound healing speed of the mice in the pet-specific wound care composite gel dressing group was significantly faster than that of the other three groups; on the 14th day after treatment, the wounds of the mice in the pet-specific wound care composite gel dressing group were basically healed and covered with hair, while the unrepaired wounds of the other three groups of mice were still visible. This shows that the pet-specific wound care composite gel dressing can effectively promote wound healing.

The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims (4)

1. The special wound care composite gel dressing for the pets is characterized by comprising the following raw materials in parts by weight: 0.3 part of florfenicol, 1 part of chitosan, 0.1 part of genipin, 407 parts of poloxamer 30, 0.1 part of acetic acid, 4 parts of methanol and 65 parts of deionized water;

the preparation method of the special wound care composite gel dressing for pets comprises the following steps:

(1) Adding chitosan into water according to a certain proportion, and adding acetic acid to dissolve the chitosan to obtain a solution 1;

(2) Adding florfenicol into methanol according to a proportion, uniformly stirring, and carrying out ultrasonic dissolution assistance to obtain a solution 2;

(3) Dropwise adding the solution 2 into the solution 1, and uniformly stirring to obtain a solution 3;

(4) Adding genipin into the solution 3 according to a proportion, and stirring 2h for crosslinking to obtain a solution 4;

(5) And adding poloxamer 407 into the solution 4 according to a proportion, uniformly stirring to swell the mixture, and obtaining the special wound care composite gel dressing for pets.

2. The composite gel dressing for pet-specific wound care according to claim 1, wherein the stirring is performed while the dripping in the step (3), and the stirring speed is 1500 r/min.

3. The composite wound care gel dressing for pets according to claim 1, wherein the crosslinking temperature in the step (4) is 50 ℃.

4. The composite wound care gel dressing for pets according to claim 1, wherein the swelling temperature in the step (5) is 4 ℃ and the time is 24 h.