A wound dressing for oral cavity and its preparation method

Abstract

The present application relates to an oral wound dressing and a preparation method thereof. The present application discloses for the first time that the Isochrysis polypeptide IZP‑2 has the effects of stopping bleeding and promoting wound healing, and further discloses an oral wound hydrogel dressing with IPZ‑2 as an active ingredient and a preparation method thereof. Finally, in vitro and model animal experiments confirmed that the oral wound hydrogel dressing with IPZ‑2 as an active ingredient described in the present application has a low water absorption and swelling rate, and can adhere to a humid and dynamic oral environment, while showing sufficient hemostatic effect and wound healing promotion effect. Compared with the traditional oral repair film (Haiao oral repair film), the oral wound hydrogel dressing with IPZ‑2 as an active ingredient accelerated the healing of full-thickness oral mucosal defects in rabbits.

Description

Technical Field

[0001] The invention belongs to the technical field of oral wound dressings, and particularly relates to an oral wound dressing and a preparation method thereof. Background Art

[0002] As an important portal of the human body, the oral cavity plays a key role in speech and food intake. The high incidence of various oral diseases, coupled with the inherent vulnerability of the oral cavity to a series of internal and external stimuli and injuries, leads to the prevalence of intraoral wounds. Intraoral wounds can be defined as any type of injury occurring in the oral cavity, including wounds of the lips, tongue, gums, cheeks, palate mucosa, and wounds involving the oropharynx, oral muscles, alveolar bones, etc.

[0003] Classification by cause includes bites, accidental injuries, postoperative wounds, and pathological lesions (such as infection, inflammation, tumors, and genetic defects).

[0004] Wounds are classified by depth as superficial wounds (involving only the superficial mucosal layer), partial-thickness wounds (deep but confined to the mucosal layer), deep wounds (penetrating the mucosa and possibly involving underlying muscle, glands, or connective tissue), and penetrating wounds (passing through the mouth to the face or neck area).

[0005] Wounds are categorized by duration, including acute wounds, such as bite wounds, and chronic wounds, such as ulcers and persistent infections.

[0006] These wounds can cause discomfort, pain, and limited movement, severely affecting patients’ quality of life and even their nutritional status, social activities, and mental health. The proper function of the oral cavity is vital and inseparable from overall physical and mental health. Therefore, careful wound care to achieve faster and better intraoral wound healing has become a vital topic.

[0007] However, the complex oral environment brings many difficulties to the treatment of oral wounds.

[0008] The oral cavity contains soft and hard tissues such as mucosa, muscles, glands, bones, and teeth. Wound repair and regeneration in this environment require a high level of coordinated growth of these spatially proximal but physiologically distinct structures. However, the repair of these structures is not synchronized. For extensive oral defects, multiple affected structures cannot be restored at the same time and they may interfere with each other. For example, teeth may cause or aggravate soft tissue injuries due to collision or accidental biting.

[0009] The oral microbiome consists of more than 1,000 microbial species with a unique spatial and structural organization. The presence of a large number of oral bacteria and other microorganisms can have a significant impact on wound healing. An imbalance in the oral microbiome may impair the proliferation of mesenchymal stem cells (MSCs) and hinder wound healing. In addition, pathogenic microorganisms may penetrate tissues and cause infection, triggering swelling, redness, and pain. Once infected, it may spread further in the local area, causing deep tissue infections such as cellulitis and abscesses, and even systemic symptoms.

[0010] The oral environment is moist and dynamic. The oral cavity is constantly exposed to external influences such as cold air, food, and drink. In addition, active movement of soft tissues and muscles during activities such as speaking or chewing prevents the wound from adequately resting and protecting. These conditions may lead to secondary injury and delayed wound healing.

[0011] The anatomy of oral tissues presents a difficult task for wound management. For example, the deep vestibule of the oral cavity is prone to scar formation in certain areas due to its webbed structure. In addition, defects in the attached gingiva attached to the alveolar bone cannot be closed without a dressing or tissue graft. Moreover, for wounds that are deep and extensive and require a lot of time to heal, factors in the oral environment that inhibit healing may outweigh those that promote healing. These large wounds may eventually experience tissue contraction or even contracture. Therefore, in pursuit of complete tissue regeneration, both to avoid scar formation and to shorten healing time, the application of functional wound dressings is essential.

[0012] Similar to skin wounds, oral wounds undergo four sequential and overlapping healing phases: hemostasis, inflammation, proliferation, and remodeling. However, the healing behavior of oral wounds and the duration of each phase differ from those of the skin. Immediately after injury, components of the coagulation cascade and inflammatory pathways at the wound site are activated, and the hemostasis and inflammation phases begin, typically lasting 4–6 days. This is followed by the proliferation phase, which is characterized by re-epithelialization and angiogenesis. Fibroblasts, endothelial cells, and newly formed capillaries interact to form granulation tissue, accompanied by collagen deposition. This phase occurs 2–10 days after injury. Remodeling begins approximately 2 weeks after injury and continues unsteadily for a year or even longer. During the remodeling phase, type III collagen is gradually absorbed and replaced by type I collagen, and the extracellular matrix (ECM) is reorganized to restore the functional needs of the newly formed tissue. Typically, acute wounds heal within a normal time frame through this physiological healing process. However, when the body is unable to restore homeostasis after injury, tissue regeneration is impaired and the healing phase is abnormally prolonged, causing the wound to become chronic.

[0013] Interestingly, distinct histological differences were observed during the re-epithelialization process of the oral mucosa and skin. In the skin, migrating keratinocytes form a thin tongue-like structure at the wound edge, crawl through the granulation tissue and meet the cells at the surrounding edge to form a continuous epidermis. However, in the oral buccal mucosa, epithelial cells form a wedge and migrate into the wound, connecting with each other to form a “V” shape, with little or no granulation tissue formation. The connected epithelium then grows toward the mucosal surface and forms a solid “delta” (Δ), after which the epithelium retracts in a remodeling phase until it returns to normal thickness. These phenomena may represent different cell migration and differentiation behaviors of these two tissues.

[0014] Intraoral dressings are inevitably affected by the oral environment, which in turn affects their function. When designing intraoral wound dressings, the characteristics of the oral environment must be considered to achieve the desired duration of action and maximum effect.

[0015] The pH of the oral environment is maintained at a near-neutral value (6.7–7.3) by the flow and buffering effects of saliva. However, the pH in the oral cavity is susceptible to fluctuations due to various perturbations, including dietary intake and intrinsic factors. Changes in pH may affect the biochemical stability of wound dressing components and affect their durability and effectiveness, including effects on degradation and release of active substances. Dressings should be designed to be pH-stable to maintain structural integrity during pH changes to ensure effective performance. In turn, the application of wound dressings can also change the local pH of the wound site. Studies have shown that increased pH is associated with lower healing rates, and wound acidification is an effective strategy to promote wound healing. Therefore, acidic wound dressings can be designed to regulate wound pH and promote healing. In addition, dressings with pH monitoring or pH responsiveness can be developed to enable them to interact with the wound environment.

[0016] All surface structures in the oral cavity are covered by acquired films, on which bacteria attach and colonize, eventually forming bacterial biofilms. Oral biofilms can form on natural structures as well as on restorative and therapeutic materials. The growth pattern of biofilms enhances the tolerance of microorganisms to antimicrobial agents, allowing them to survive for a long time under harsh and changing conditions. Biofilms form a physical barrier between tissues and dressings, which reduces the interaction of wound dressings with tissue surfaces and reduces the therapeutic efficiency of antimicrobial and other bioactive agents. In addition, wound dressings act as bioreactors, supporting the growth of biofilms, allowing microorganisms to continue to spread from dressings to wounds. To address these issues, a variety of anti-biofilm materials have been designed, mainly involving strategies such as physical stimulation, oxidative stress, and anti-adhesion. Nanoparticles and nanocoatings have also been used as effective antimicrobial agents to regulate microbial colonization and biofilm formation in wounds.

[0017] Various oral diseases can affect the function of intraoral wound dressings by altering oral surface structures and tissue responses. For example, xerostomia due to Sjögren’s syndrome, medications, or radiation therapy can significantly reduce salivary flow, which can reduce the effectiveness of wound dressings by altering the oral environment to make it less conducive to healing and more susceptible to infection. Oral mucosal diseases, such as oral lichen planus, which varies in form from asymptomatic reticular to painful erosive subtypes, can significantly complicate the effectiveness of intraoral wound dressings due to increased exudate and heightened tissue sensitivity.

[0018] To achieve optimal wound healing, an ideal oral wound dressing should possess the following properties: 1) excellent biocompatibility and nontoxicity, 2) the ability to promote wound healing, 3) strong adhesion in a moist environment, 4) reliable protection of exposed tissue, 5) the ability to isolate the wound from microorganisms, 6) mechanical properties that match the applied tissue, 7) strong stability despite environmental changes, 8) easy removal after recovery or coordinated degradation with the healing process, and 9) convenience for clinical use.

[0019] At present, traditional dressings still occupy a dominant position in clinical practice. However, the oral cavity is inherently moist, which makes modern moisturizing dressings particularly advantageous. Various types of modern water-activated dressings have been applied to the oral cavity, such as films, hydrogels, sponges, foams, powders, sprays, etc. Each material has its own unique properties and advantages.

[0020] Films are thin, flexible sheets that can be easily stored and immediately applied to the wound surface. They can be manufactured by a variety of methods, including solution casting, melt extrusion, electrospinning, layer-by-layer assembly, etc. They are generally permeable to gases and water vapor, but impermeable to liquids and bacteria. They can be transparent or translucent, allowing for simple monitoring of the wound at all times. The main advantages of film dressings are the ease of immediate application and comfort due to their thin and soft nature. However, their non-absorbent nature may lead to accumulation or leakage of excess exudate, so they should be changed every few days.

[0021] Hydrogels are cross-linked macromolecular networks that can contain up to 99% water by weight and are particularly friendly to water-rich biological environments. They can be designed to be injectable, applied via a syringe and gel in vivo. In this way, the material can adapt to irregularly shaped wounds. Due to their good degradation characteristics, they are also a good choice for targeted delivery of bioactive substances. One disadvantage of hydrogels is their relatively poor mechanical properties. Fortunately, due to their plasticity and adjustability, hydrogels can be customized and optimized to meet various clinical needs by changing the formulation, adding functional ingredients or adjusting the physical properties.

[0022] Sponges and foams have a porous structure and exhibit high adsorption and moisture retention capabilities. Sponges are usually made of synthetic materials, with chitosan being used in most studies, while foams are usually made of polyurethane or silicone-based materials. They can both absorb water from the blood to concentrate coagulation factors and accelerate hemostasis, as well as fill wound cavities. In addition, foam dressings are usually breathable, facilitating gas exchange. Therefore, they are particularly suitable for use over bony prominences or exudative cavities and should be replaced when saturated with exudate. However, sponges and foams are usually non-adhesive. Regenerative tissue may grow into them, which may cause secondary injury.

[0023] Powders are a new form of wound dressing with unique properties. Usually, they are obtained by grinding the original material. Unlike traditional powders, the new powder materials can self-crosslink in situ to form a tight hydrogel and seal the tissue when absorbing interfacial water or blood, so they are often used as hemostatic materials. Just like injectable hydrogels, powders can adapt to wounds of various shapes. However, the wet adhesion properties of powders still need to be improved. The application of powder materials is not very convenient, and it is difficult to control the dosage to achieve complete gelation. In addition, powders are easy to be swallowed, resulting in treatment failure, and may even cause gastrointestinal adverse reactions or suffocation.

[0024] Wound dressings in spray form can be easily applied to large and irregular wound areas and form a tight interface with the wound surface. Some spray dressings form a viscous gel in situ and provide protection after being sprayed onto the wound. They can also load active ingredients and enhance their penetration into the wound area. However, the composition of spray dressings needs to be carefully adjusted to achieve optimal viscosity and uniform coverage.

[0025] Commercial products of various dosage forms for intraoral wounds have successfully passed clinical trials and are on the market. These commercial products are mainly targeted at oral surgical wounds or superficial mucosal wounds, and their effects are mainly focused on hemostasis, pain control and protection, and they focus on the convenience of clinical use. However, the functions of existing products are often limited. They can either only treat simple wounds or have insufficient ability to promote wound healing. Therefore, in the context of new materials and technologies, the goals of developing new intraoral wound dressings are multifunctionality, shortening wound healing time, and improving the overall efficacy of healing outcomes.

[0026] Isochrysis zhangjiangensis Hu1992 belongs to Chrysophyta, Chrysophyceae, Isochrysidales, Isochrysidaceae, and grows in the sea area of ​​Nansan Island, Zhanjiang City, Guangdong Province. Isochrysis zhangjiangensis has the characteristics of high nutritional value and fast reproduction. It is rich in polyunsaturated fatty acids, and the cell metabolites include pigments, polysaccharides and proteins. Some studies have found that under the environmental stress of heavy metal cadmium, the production and removal of superoxide free radicals in Isochrysis Zhanjiangensis is balanced. When Isochrysis Zhanjiangensis is damaged by oxidation, the damage caused by active oxygen can be mitigated by the antioxidant enzyme system and non-enzymatic substances (Tian Dan, Zhao Wen, Wang Yuan, et al.; Effects of cadmium stress on the growth and antioxidant system of two marine microalgae, [J]. Journal of Dalian Fisheries University, 2010, 25(5): 417-421). Some studies have also found that under the environmental stress of plasticizer DIBP, the superoxide dismutase (SOD) content of Isochrysis Zhanjiangensis decreased and the reduced glutathione (GSH) content increased to degrade peroxidized substances, proving that Isochrysis Zhanjiangensis has antioxidant activity (Jiang Li, Geng Qinghua, Li Chengyong, et al., Effects of DIBP on the growth and antioxidant system of two marine microalgae, [J]. Environmental Science and Technology, 2015, 38(12Q): 7-10).

[0027] Chinese patent CN108888752B discloses the use of Isochrysis chrysophyte polypeptide IZP-2 in the preparation of drugs for preventing alcoholic liver damage, wherein the amino acid sequence of the Isochrysis chrysophyte polypeptide IZP-2 is Phe-GIu-IIe-His-Cys-Cys-GIy. The polypeptide IZP-2 derived from Isochrysis chrysophyte can scavenge free radicals, is non-toxic to cells, inhibits alcohol-induced cell damage, inhibits DNA breakage in oxidation reactions, and can reduce intracellular ROS content.

[0028] The molecular weight of IZP-2 is 807.95, and the chemical structure is as follows:

[0029]

[0030] However, there is no report on other activities or applications of the above-mentioned IZP-2 in the prior art. Summary of the invention

[0031] The patent application of the present invention has further studied the above-mentioned heptapeptide IZP-2 and found that it has good hemostasis and wound healing effects.

[0032] Here, we first disclose the use of the heptapeptide IZP-2 for wound hemostasis and wound healing promotion, characterized in that the chemical structure of the heptapeptide IZP-2 is as follows:

[0033] .

[0034] Secondly, an oral wound dressing with heptapeptide IZP-2 as an active ingredient is disclosed, and the preparation method thereof is as follows:

[0035] Step 1: Synthesis of genipin cross-linked G-CS hydrogel:

[0036] The genipin solution was added to the high viscosity chitosan aqueous solution and mixed under vigorous stirring. Then, the mixture was degassed, poured into a mold, and reacted in an incubator at 50°C, and the resulting hydrogel was immersed in a NaOH solution for deprotonation. The hydrogel was immersed in distilled water and gradient ethanol aqueous solutions in turn to remove NaOH and perform solvent replacement. The resulting hydrogel was dried with supercritical carbon dioxide to obtain a dry G-CS hydrogel.

[0037] Step 2: Preparation of polyacrylamide precursor solution

[0038] The acrylamide solution, MBAA solution and ammonium persulfate solution were mixed to prepare a polyacrylamide precursor solution.

[0039] Step 3: Preparation of blank hydrogel

[0040] The G-CS hydrogel was rehydrated in a gradient ethanol-water solution (from 100% to 0%) to avoid structural collapse due to the surface tension of water. The hydrated network structure was immersed in a polyacrylamide precursor solution to allow polymer penetration and grafting reaction, and then incubated at 60 °C for polymerization. The resulting composite material was a light yellow hydrogel.

[0041] Step 4: Drug loading

[0042] The blank hydrogel was collected and soaked in an IZP-2 aqueous solution at room temperature to obtain an oral wound hydrogel dressing with IZP-2 as an active ingredient.

[0043] The mass percentage of the IZP-2 in the obtained hydrogel dressing is: 0.01%-0.08%.

[0044] The mass percentage of the IZP-2 in the obtained hydrogel dressing is: 0.01%.

[0045] The mass percentage of the IZP-2 in the obtained hydrogel dressing is: 0.04%.

[0046] The mass percentage of the IZP-2 in the obtained hydrogel dressing is: 0.08%.

[0047] Beneficial effects of the present invention: This application discloses for the first time that the Isochrysis polypeptide IZP-2 has the effects of stopping bleeding and promoting wound healing, and further discloses an oral wound hydrogel dressing with IPZ-2 as an active ingredient and a preparation method thereof. Finally, in vitro and model animal experiments confirmed that the oral wound hydrogel dressing with IPZ-2 as an active ingredient described in this application has a low water absorption and swelling rate, and can adhere to a humid and dynamic oral environment. At the same time, it shows sufficient hemostatic effect and wound healing effect. Compared with the traditional oral repair film (Haiao oral repair film), the oral wound hydrogel dressing with IPZ-2 as an active ingredient accelerated the healing of full-thickness oral mucosal defects in experimental rabbits.

[0048] Abbreviations:

[0049] PAM: Polyacrylamide

[0050] MBAA: N,N-methylenebisacrylamide

[0051] APS: Ammonium Persulfate

[0052] HV-CS: High viscosity chitosan (>400 m. Pas, deacetylation degree>90%)

[0053] C-GS: Genipin cross-linked chitosan DETAILED DESCRIPTION

[0054] The present invention is further described below with reference to specific examples, but the examples do not limit the present invention in any form. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0055] Unless otherwise specified, the reagents and materials used in the following examples are commercially available.

[0056] Example 1 Preparation of hydrogel dressing with IZP-2 as active ingredient

[0057] Step 1: Synthesis of genipin cross-linked G-CS hydrogel:

[0058] 1 mL of 1% genipin solution was added to 30 mL of 2% HV-CS solution and mixed under vigorous stirring. Then, the mixture was degassed at 5000 rpm for 10 min, poured into a mold, and stored in an incubator at 50 °C. The reaction lasted for 6 h, and then the resulting hydrogel was immersed in 1M NaOH for deprotonation. The hydrogel was immersed in distilled water and gradient ethanol aqueous solution (from 10% to 100%) to remove NaOH and perform solvent replacement. The resulting hydrogel was dried with supercritical carbon dioxide to obtain a dry G-CS hydrogel.

[0059] Step 2: Preparation of polyacrylamide precursor solution

[0060] A polyacrylamide precursor solution was prepared by mixing 10 mL of a 12% acrylamide solution, 72 μL of a 2% MBAA solution, and 300 μL of a 0.27 M ammonium persulfate solution.

[0061] Step 3: Preparation of blank hydrogel

[0062] The G-CS hydrogel was rehydrated in a gradient ethanol aqueous solution (from 100% to 0%) to avoid structural collapse due to the surface tension of water. The hydrated network structure was immersed in a polyacrylamide precursor solution for 1 h to allow polymer penetration and grafting reaction, and then incubated at 60 ° C for polymerization and washed with distilled water to remove unreacted monomers. The resulting composite material was a light yellow hydrogel.

[0063] Step 4: Drug loading

[0064] The blank hydrogel (volume of about 50 ml) was collected and immersed in 100 ml of IZP-2 solution of different concentrations (0.01, 0.04 and 0.08 w / v%) contained in a beaker at room temperature for 24 h to obtain hydrogel dressing samples 1-3 containing different concentrations of IZP-2.

[0065] Freeze-drying can obtain drug-loaded dry hydrogel powder or flakes.

[0066] After drug loading, the content of IZP-2 in the beaker solution, and indirectly the mass percentage of IZP-2 in the drug-loaded hydrogel dressing was 0.01%, 0.04% and 0.08%.

[0067] In addition, the blank hydrogel prepared in step 3 is used as comparative example 1 to further illustrate the performance of the gel dressing obtained in example 1.

[0068] Example 2: In vitro swelling and stretching test of hydrogel in Example 1

[0069] The swelling behavior of various hydrogels was determined by comparing their weight before and after immersion in artificial saliva. 50 mg of dry hydrogel (Wd) was placed in 50 mL of 37°C artificial saliva for 24 h. After that, the immersed hydrogel was taken out, the excess liquid on the surface was blotted with filter paper, and then weighed as Ws.

[0070] The swelling rate (%) is calculated as follows: (Ws-Wd) / Wd×100%

[0071] The tensile test was performed using a universal testing machine equipped with a 500N load cell. The hydrogel was prepared into a rectangular sample (3 cm long × 1 cm wide × 1 mm thick) and clamped with a tensile fixture and stretched at a speed of 10 mm / min until it broke. The maximum stress (KPa) at the time of each sample breaking was recorded.

[0072] .

[0073] The swelling properties of hydrogels are considered to be their key features. An appropriate degree of swelling indicates that the hydrogel can absorb blood and exudate from the wound, helping to reduce the liquid at the interface and allowing the patch to fully contact the tissue surface and adhere firmly. On the contrary, sensitivity to water environments can lead to decreased mechanical properties, dimensional instability, and impaired adhesion. The samples were immersed in artificial saliva to simulate more realistic conditions. Due to their hydrophilicity and porous structure, the water absorption and swelling percentages of the blank hydrogel and drug-loaded samples 1-3 shown in Comparative Example 1 did not change significantly, indicating that drug loading did not affect the swelling properties of the hydrogel. And the drug-loaded hydrogel samples 1-3 can all be used in a humid oral environment.

[0074] Given that the oral mucosa moves during speaking and chewing, an ideal viscoelastic hydrogel should exhibit appropriate stretchability.

[0075] Experiments have shown that the addition of IZP-2 did not significantly reduce the tensile properties of the original hydrogel, and the resulting drug-loaded hydrogel dressing can still be used in the oral cavity.

[0076] Example 3 Example 1 Adhesion properties of hydrogel

[0077] The adhesion of the hydrogel samples 1-3 obtained in Example 1 and the hydrogel of Comparative Example 1 was tested using a universal mechanical analyzer. Specifically, the dried hydrogel was hydrated and prepared into a film, cut into a size of 15 mm (length) × 10 mm (width) × 1 mm (thickness), and placed between two pieces of fresh porcine cheek tissue, and then gentle pressure was applied for 10 seconds to achieve adhesion. Then, a lap shear test was performed using a 500N load cell at a loading speed of 10 mm / min.

[0078] Adhesion strength (kPa) = maximum load (kN) / area (m²) to calculate.

[0079] The blood stain sample was prepared by covering the surface of the hydrogel sample with 20 μL of fresh SD rat blood. The sample was then placed between two pieces of porcine cheek tissue and the same procedure was performed for the lap shear test.

[0080] .

[0081] As shown in the data in the above table, the IZP-2 drug-loaded gel dressing prepared in Examples 1-3 of the present application has good adhesion properties between blood-free and blood-containing pig cheek tissues, and its adhesion performance far exceeds that of the fibrin adhesive used in clinical applications.

[0082] Example 4 Example 1 In vivo hemostatic ability test of hydrogel

[0083] In order to detect the hemostatic ability of the drug-loaded hydrogel obtained in Example 1 in vivo, a rat liver bleeding model (SD rats, 300±20 g male) was used. The steps are as follows:

[0084] Rats were anesthetized with sodium pentobarbital and then fixed on a surgical cork board tilted at approximately 45°. The rat liver was exposed through an abdominal incision, and the serous fluid surrounding the liver was carefully removed. A pre-weighed filter paper was placed under the liver on the paraffin film. Liver bleeding was induced using a drill with a diameter of 5 mm, and a circular hydrogel patch with a diameter of 10 mm was immediately placed on the bleeding site. When the bleeding stopped and no bleeding was seen after the dressing was removed, the time from bleeding to stopping was recorded as the hemostasis time (s), and the filter paper containing the absorbed blood was weighed to calculate the total blood loss (g). No treatment was performed after puncturing the liver as a blank control.

[0085] .

[0086] This example further evaluates the hemostatic ability of the hydrogel obtained in Example 1 by testing the blood loss and hemostasis time in a rat liver bleeding model. The prior art does not report other effects of IZP-2 besides anti-oxidation. This application confirms for the first time that IZP-2 has significant hemostatic effects. Bleeding caused by trauma to the rat liver can be significantly shortened, which is specifically reflected in that the hemostasis time can be significantly shortened and the amount of bleeding can be reduced. These results show that the oral mucosal hydrogel dressing with IZP-2 as the main component has a rapid and powerful hemostatic ability, and is expected to be applied to full-thickness oral mucosal defects with severe bleeding.

[0087] Example 5 The drug-loaded hydrogel obtained in Example 1 is used to treat rabbit palate mucosal defects

[0088] In order to further simulate clinical applications, we selected a larger animal, the New Zealand white rabbit (male, 2.5±0.2kg), to create a palatal mucosal defect model, and sutured the Haiao oral tissue repair membrane (Yantai Zhenghai Biotechnology Co., Ltd.) on the wound as a positive control group. A square full-thickness palatal mucosal defect with a side length of 5 mm was created and covered with the drug-loaded hydrogel dressing obtained in Example 1 or sutured with a commercial product (Haiao oral tissue repair membrane). Mucosal defects that were only pulled together with sutures were designated as the positive control group. Animals that were not treated were designated as the model control group. On days 1, 4, and 7 after surgery (or administration of hydrogel dressing samples), rabbits in all groups (n=3) were injected with urethane for general anesthesia through the ear vein, and the wound healing rate (%) was determined by measuring the defect area.

[0089] In this experiment, the feeding, restraint (ensuring that the animals are safe, stable, and will not attack the experimenters), oral administration of dressings, general anesthesia, and defect area measurement of the experimental animals were completed by professional nursing staff.

[0090] The wound healing rates of the experimental animals obtained in this experiment are shown in the following table (n=3):

[0091] .

[0092] In this example, we compared the therapeutic effects of IZP-2 hydrogel dressing samples 1-3 obtained in the example, blank hydrogel dressing (Comparative Example 1) and positive control Haiao oral repair membrane. Rabbits were selected for the experiment because the operating space in the rabbit's mouth is larger, and the positive control Haiao oral repair membrane can be fixed with sutures. A full-thickness palatal mucosal defect with a side length of 5 mm square was made in the palate of each rabbit. The experimental animals were divided into 6 groups according to the sample application, namely, Example 1 Sample 1-3 Group, Comparative Example 1 Group, Model Group and Positive Control Group. The postoperative changes in mucosal defects showed that Example 1 Sample 1-3 Group promoted tissue repair and wound healing faster than the positive control group Haiao oral repair membrane. On the 4th day, significant differences in wound healing between the groups were observed.

[0093] The wound healing rates of sample groups 1-3 in Example 1 were significantly higher than those of the other groups. And as the amount of IZP-2 added to the samples increased, the wound healing rates increased slightly.

[0094] Haiao oral repair membrane is a bovine acellular dermal matrix that has been widely used in clinical oral mucosal repair. However, it requires additional hemostasis procedures and antibiotic applications, which may slow down the healing process and increase the development of drug resistance. In addition, the lack of adhesion requires suturing at the wound site, which increases the difficulty of surgical operations in limited areas of the oral cavity. In contrast, the hydrogel dressing obtained in Example 1 of the present application exhibits a strong ability to stop bleeding and promote wound healing. It is also easy to operate, allowing efficient application in the oral environment.

[0095] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. The use of the heptapeptide IZP-2 for preparing a medicine for stopping bleeding and promoting wound healing, characterized in that: The chemical structure of the heptapeptide IZP-2 is as follows: 。 2. The use according to claim 1, characterized in that The medicine is an oral wound dressing.

3. The use according to claim 2, characterized in that The mass percentage of the IZP-2 in the oral wound dressing is 0.01%-0.08%.

4. The use according to claim 2, characterized in that The mass percentage of the IZP-2 in the oral wound dressing is: 0.01%.

5. The use according to claim 2, characterized in that The mass percentage of the IZP-2 in the oral wound dressing is: 0.04%.

6. The use according to claim 2, characterized in that The mass percentage of the IZP-2 in the oral wound dressing is 0.08%.

7. The use according to any one of claims 2 to 6, characterized in that: The preparation method of the oral wound dressing is as follows: Step 1: Synthesis of genipin cross-linked G-CS hydrogel: The genipin solution was added to the high viscosity chitosan aqueous solution and mixed under strong stirring; then, the mixture was degassed, poured into a mold, and reacted in an incubator at 50°C, and then the obtained hydrogel was immersed in a NaOH solution for deprotonation; the hydrogel was immersed in distilled water and gradient ethanol aqueous solution in turn to remove NaOH and perform solvent replacement; the obtained hydrogel was dried with supercritical carbon dioxide to obtain a dry G-CS hydrogel; Step 2: Preparation of polyacrylamide precursor solution mixing an acrylamide solution, an N,N-methylenebisacrylamide solution and an ammonium persulfate solution to prepare a polyacrylamide precursor solution; Step 3: Preparation of blank hydrogel The G-CS hydrogel was rehydrated in a gradient ethanol-water solution to avoid structural collapse due to the surface tension of water; The hydrated mesh structure was immersed in a polyacrylamide precursor solution to allow polymer penetration and grafting reaction, and then incubated at 60 °C for polymerization; The unreacted monomers were removed by washing with distilled water, and the obtained composite material was a light yellow hydrogel; The gradient ethanol aqueous solution concentration ranges from 100% to 0%; Step 4: Drug loading The blank hydrogel was collected and soaked in an IZP-2 aqueous solution at room temperature to obtain an oral wound hydrogel dressing with IZP-2 as an active ingredient.

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