Post-operative endometrial protective and anti-adhesion repair dressing

Abstract

This application discloses a postoperative endometrial protective anti-adhesion repair dressing for uterine cavity surgery. The dressing is a sterile hydrogel preparation comprising gradient cross-linked sodium hyaluronate, recombinant type III humanized collagen, and carboxymethyl chitosan. Therefore, this application uses medical-grade natural genipin to replace toxic chemical cross-linking agents such as BDDE to construct a gradient cross-linked sodium hyaluronate system, which is non-irritating to the uterine cavity mucosa, ensuring the safety of postoperative recovery. By precisely compounding high-molecular-weight and low-molecular-weight sodium hyaluronate and accurately controlling the cross-linking time, the anti-adhesion effect and postoperative repair quality are significantly improved. The gel rheological properties are optimized, resulting in a long retention time in the uterine cavity, excellent uterine cavity adaptability, and a stable and reliable physical barrier function. It integrates anti-adhesion, wound protection, and lubrication protection functions, and adopts a pre-filled uterine cavity-specific pusher design, allowing for immediate use without the need for additional intraoperative configuration, effectively reducing the risk of cross-contamination.

Description

Technical Field

[0001] This application relates to the technical field of dressings, and more particularly to anti-adhesion repair dressings for endometrial protection after uterine cavity surgery. Background Technology

[0002] Intrauterine adhesions are the most common complication after gynecological intrauterine procedures. In severe cases, they can lead to amenorrhea, infertility, recurrent miscarriages, and other adverse consequences, seriously damaging women's reproductive health, placing a great burden on patients' physical and mental well-being, and increasing the difficulty of clinical diagnosis and treatment. Currently, intrauterine anti-adhesion gel is the first-line consumable for the clinical prevention of intrauterine adhesions and plays an important role in postoperative adhesion prevention treatment. However, related products have many shortcomings.

[0003] First, existing products generally use BDDE as a chemical cross-linking agent. This substance has strong cytotoxicity and is prone to remaining in the human uterine cavity, which can lead to local inflammatory reactions in the uterine cavity, inhibit the endometrial repair process, and may even aggravate wound adhesions. This does not meet the requirements for safe use and poses potential clinical risks.

[0004] Secondly, most products degrade completely within 2 weeks after the operation, failing to cover the 28-day physiological repair window of the endometrium. This results in the loss of the physical barrier function before the wound has healed, significantly reducing the anti-adhesion effect. A few products have a degradation cycle of more than 8 weeks, and long-term retention in the uterine cavity can easily cause foreign body reactions, interfere with the normal physiological repair of the endometrium, and hinder the patient's postoperative recovery.

[0005] Meanwhile, some products have excessively high viscosity, making them difficult to inject during surgery and unable to evenly cover areas prone to adhesions, such as the uterine horn and fallopian tube openings, creating blind spots in protection. Other products have excessively low viscosity, making them prone to leakage from the cervix after surgery, with less than 24 hours of retention time in the uterine cavity. This makes it difficult to form a continuous and complete physical isolation barrier, failing to effectively prevent contact with the wound and resulting in poor anti-adhesion effects.

[0006] In addition, existing products only have a single physical isolation and anti-adhesion function, which lacks targeted protection for the damaged endometrial wound after uterine cavity operation. They cannot help reduce postoperative inflammatory response, nor can they help improve mild adhesions that have already formed. Their functions are quite limited and cannot meet the comprehensive clinical needs for postoperative wound repair and anti-adhesion. Finally, most products are packaged in vials, which need to be extracted and prepared during the operation, increasing the risk of cross-contamination. Moreover, there is no dedicated uterine cavity push device, which cannot achieve precise and uniform application, making the operation cumbersome.

[0007] Application content

[0008] This application aims to address, at least to some extent, the technical problems in the related art.

[0009] To achieve the above objectives, this application proposes a post-operative endometrial protective anti-adhesion repair dressing. The dressing is a sterile hydrogel formulation comprising gradient-crosslinked sodium hyaluronate, recombinant type III humanized collagen, and carboxymethyl chitosan. The gradient-crosslinked sodium hyaluronate is prepared by crosslinking high-molecular-weight sodium hyaluronate and low-molecular-weight sodium hyaluronate using the natural crosslinking agent genipin to form a three-dimensional network hydrogel. This three-dimensional network hydrogel can form a physical barrier on the uterine cavity wall, preventing contact between the damaged endometrial anterior and posterior walls, uterine horns, and fallopian tube openings. The recombinant type III humanized collagen and the carboxymethyl chitosan work synergistically to form a physical moisturizing protective film on the damaged endometrial wound, isolating it from inflammatory factors and reducing postoperative bleeding and exudation. The gradient-crosslinked sodium hyaluronate achieves controllable degradation by adjusting the ratio of high-molecular-weight sodium hyaluronate to low-molecular-weight sodium hyaluronate and the degree of crosslinking of genipin, with the degradation cycle matching the physiological repair cycle of the endometrium.

[0010] In addition, the application may also include the following additional technical features:

[0011] Specifically, the three-dimensional network structure of the gradient crosslinked sodium hyaluronate is porous and is used to load drugs or bioactive factors. The pore size of the porous structure ranges from 10 to 100 μm. The drugs or bioactive factors are loaded inside the porous structure by physical adsorption or encapsulation, and the loading amount accounts for 0.1% to 5.0% of the total mass of the hydrogel.

[0012] Specifically, the mass ratio of high molecular weight sodium hyaluronate to low molecular weight sodium hyaluronate is 1:1 to 5:1.

[0013] Specifically, the recombinant type III humanized collagen and carboxymethyl chitosan are bound together through electrostatic interaction or hydrogen bonding to form a physical moisturizing protective film on the wound surface.

[0014] Specifically, the hydrogel formulation of the dressing is in an injectable fluid state to accommodate different uterine cavity shapes.

[0015] Specifically, the dressing further includes at least one of a hemostatic component or an anti-inflammatory drug, wherein the hemostatic component or anti-inflammatory drug is dispersed in the three-dimensional mesh hydrogel.

[0016] Specifically, the drug includes at least one of antibiotics, anti-inflammatory drugs, and hemostatic drugs, and the bioactive factor includes at least one of epidermal growth factor, fibroblast growth factor, and vascular endothelial growth factor.

[0017] Specifically, the hemostatic component is at least one of thrombin and chitosan quaternary ammonium salt, and the anti-inflammatory drug is a nonsteroidal anti-inflammatory drug or an antibiotic, which is evenly dispersed and does not damage the three-dimensional network structure of the hydrogel.

[0018] Specifically, the mass ratio of the recombinant type III humanized collagen to the carboxymethyl chitosan is 2:1-4:1, and the total mass of the two accounts for 0.5%-2.0% of the total mass of the sterile hydrogel preparation.

[0019] In summary, the beneficial effects of the post-operative endometrial protective and anti-adhesion repair dressing of this application are as follows:

[0020] 1. Medical-grade natural genipin is used to replace toxic chemical cross-linking agents such as BDDE to construct a gradient cross-linked sodium hyaluronate system. The residual amount of cross-linking agent is relatively low, the cytotoxicity reaches level 0, it is non-irritating to the uterine mucosa, will not cause local inflammatory reactions, and will not hinder endometrial repair due to the residue of cross-linking agent, thus ensuring the safety of patients' postoperative recovery.

[0021] 2. By precisely blending high-molecular-weight and low-molecular-weight sodium hyaluronate and controlling the cross-linking time, the gel achieves customized and controllable degradation over 4-6 weeks, precisely matching the 28-day physiological repair cycle of the endometrium, significantly improving the anti-adhesion effect and postoperative repair quality.

[0022] 3. Optimize the rheological properties of the gel and precisely control the dynamic viscosity and adhesion force to ensure smooth injection during the procedure and uniformly cover the uterine cavity wall, uterine horn, fallopian tube opening and other high-incidence adhesion sites. It also has excellent anti-erosion and anti-loss capabilities, long retention time in the uterine cavity, excellent uterine cavity adaptability and stable and reliable physical barrier function.

[0023] 4. It integrates anti-adhesion, wound protection and lubrication protection functions, fully covering the diverse clinical needs after intrauterine procedures. It adopts a pre-filled intrauterine thruster design, which can be used immediately without the need for additional configuration during the operation, effectively reducing the risk of cross-contamination. Detailed Implementation

[0024] To make the technical means, inventive features, objectives, and effects of this application readily understandable, this application is further described below. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0025] The endometrial protective and anti-adhesion repair dressing for post-hysteroscopic surgery in this application uses gradient cross-linked sodium hyaluronate, prepared by cross-linking high molecular weight sodium hyaluronate and low molecular weight sodium hyaluronate with the natural cross-linking agent genipin, forming a stable three-dimensional network hydrogel structure. Genipin, as a natural cross-linking agent, has advantages over chemical cross-linking agents, such as good biocompatibility, no cytotoxicity, and biodegradability, effectively preventing harmful substances generated during the cross-linking process from causing secondary irritation to the damaged endometrial wound.

[0026] This three-dimensional mesh hydrogel possesses excellent biocompatibility and tissue adhesion. After injection into the uterine cavity post-surgery, it rapidly forms a dense and soft physical barrier on key areas such as the uterine cavity wall, the anterior and posterior walls of the damaged endometrium, the uterine horns, and the fallopian tube openings. This barrier effectively prevents direct contact between wound tissues, reduces the probability of wound adhesions, and creates a stable and undisturbed environment for the physiological repair of the endometrium.

[0027] Meanwhile, the gradient cross-linking structure achieves controllable degradation of the hydrogel by precisely adjusting the compounding ratio of high molecular weight sodium hyaluronate and low molecular weight sodium hyaluronate, as well as the degree of cross-linking of genipin. Its degradation cycle strictly matches the physiological repair cycle of the endometrium, which can not only play a protective role during the repair period, but also gradually degrade after the endometrium is repaired, without the need for a second surgery to remove it, reducing patient pain and the risk of postoperative infection.

[0028] Recombinant type III humanized collagen and carboxymethyl chitosan are used as auxiliary repair components in dressings. Their synergistic effect further enhances the repair of endometrial wounds. Recombinant type III humanized collagen has a structure highly homologous to human collagen, exhibiting excellent biocompatibility. It can quickly adhere to damaged endometrial wounds, providing scaffold support for cell proliferation and migration. Carboxymethyl chitosan possesses good moisturizing, antibacterial, and anti-inflammatory properties, reducing wound moisture loss and maintaining a moist environment, thus providing suitable conditions for cell repair.

[0029] The two are tightly bound together through electrostatic interaction or hydrogen bonds, forming a uniform physical moisturizing protective film on the damaged endometrial wound. This protective film can not only lock in the wound moisture, but also effectively isolate the wound from the stimulation of intra-abdominal inflammatory factors and foreign bodies, reduce postoperative wound bleeding and tissue exudation, relieve wound edema and inflammatory response, accelerate the wound healing process, and promote the recovery of endometrial function.

[0030] Specifically, the three-dimensional network structure of gradient cross-linked sodium hyaluronate is porous and can be used to load drugs or bioactive factors. The pore size of the porous structure ranges from 10 to 100 μm. Drugs or bioactive factors are loaded inside the porous structure through physical adsorption or encapsulation, and the loading amount accounts for 0.1% to 5.0% of the total mass of the hydrogel.

[0031] It should be noted that the three-dimensional network structure formed by gradient cross-linking of sodium hyaluronate exhibits uniform porosity. This structural design not only enhances the hydrogel's permeability and tissue compatibility but also endows it with excellent drug or bioactive factor loading capacity. The pore size of the porous structure is strictly controlled within 10-100 μm. This pore size range ensures successful loading of drugs or bioactive factors while preventing rapid leakage and achieving slow release. Drugs or bioactive factors are loaded into the porous structure through physical adsorption or encapsulation, with the loading amount strictly controlled between 0.1% and 5.0% of the total hydrogel mass. This loading ratio ensures an effective drug concentration for therapeutic effect without compromising the three-dimensional network structure of the hydrogel due to excessive loading, thus ensuring its physical isolation and controllable degradation functions remain unaffected.

[0032] Specifically, the mass ratio of high molecular weight sodium hyaluronate to low molecular weight sodium hyaluronate is 1:1 to 5:1.

[0033] It should be noted that high molecular weight sodium hyaluronate is primarily responsible for constructing the framework structure of the three-dimensional network hydrogel, enhancing its mechanical strength and physical barrier properties, ensuring stable adhesion within the uterine cavity, and effectively preventing contact with the wound surface. Low molecular weight sodium hyaluronate, on the other hand, has better permeability and degradability, promoting the proliferation and repair of wound cells while regulating the overall degradation rate of the hydrogel, ensuring a precise match between the degradation cycle and the endometrial repair cycle. Depending on the size of the postoperative wound and the specific repair needs, this ratio can be flexibly adjusted within a certain range to achieve personalized protection and repair.

[0034] Specifically, recombinant type III humanized collagen and carboxymethyl chitosan are bound together by electrostatic interaction or hydrogen bonding to form a physical moisturizing protective film on the wound surface. The mass ratio of recombinant type III humanized collagen to carboxymethyl chitosan is 2:1-4:1, and the total mass of the two accounts for 0.5%-2.0% of the total mass of the sterile hydrogel preparation.

[0035] It should be noted that the mass ratio of recombinant type III humanized collagen to carboxymethyl chitosan is 2:1-4:1, and their total mass accounts for 0.5%-2.0% of the total mass of the sterile hydrogel formulation. This ratio is designed to maximize their synergistic repair effects: a higher proportion of collagen enhances the wound scaffold support and accelerates cell proliferation; a higher proportion of carboxymethyl chitosan improves moisturizing and antibacterial effects and alleviates wound inflammation. Controlling the total mass percentage avoids excessive components that could lead to abnormal hydrogel viscosity, ensuring injectability and tissue adhesion, while also preventing adverse effects on endometrial repair.

[0036] Specifically, the hydrogel formulation of the dressing is in an injectable fluid state to accommodate different uterine cavity shapes.

[0037] It should be noted that, due to the differences in uterine cavity morphology among different patients, the uterine cavity may appear irregular after surgery. The injectable fluid state allows the dressing to automatically fill according to the actual shape of the uterine cavity after injection, ensuring that the dressing can evenly cover the inner wall of the uterine cavity and all damaged wounds, including hidden areas such as the uterine horns and fallopian tube openings. This avoids poor anti-adhesion effect and incomplete repair caused by the dressing not being able to adhere to the wound.

[0038] Specifically, the drug includes at least one of antibiotics, anti-inflammatory drugs, and hemostatic drugs, and the bioactive factor includes at least one of epidermal growth factor, fibroblast growth factor, and vascular endothelial growth factor.

[0039] It should be noted that antibiotics such as cephalosporins and penicillins, which are commonly used in clinical practice, can be selected to prevent or treat postoperative intrauterine infections; anti-inflammatory drugs, in addition to steroidal anti-inflammatory drugs, can also be glucocorticoids, which are suitable for patients with severe wound inflammation; hemostatic drugs, in addition to thrombin and chitosan quaternary ammonium salts, can also be tranexamic acid, etc., to further improve the hemostatic effect.

[0040] Bioactive factors mainly include at least one of epidermal growth factor, fibroblast growth factor, and vascular endothelial growth factor. Epidermal growth factor can promote the proliferation and differentiation of epidermal cells and accelerate wound healing; fibroblast growth factor can promote fibroblast proliferation, synthesize collagen, and enhance wound repair ability; vascular endothelial growth factor can promote angiogenesis, improve blood circulation in the wound, provide sufficient nutrition for wound repair, further shorten the repair cycle, and improve the quality of endometrial repair.

[0041] Specifically, the dressing also includes at least one of a hemostatic component or an anti-inflammatory drug, which is dispersed in a three-dimensional network hydrogel. The hemostatic component is at least one of thrombin or chitosan quaternary ammonium salt, and the anti-inflammatory drug is a nonsteroidal anti-inflammatory drug or an antibiotic. The dispersion is uniform and does not damage the three-dimensional network structure of the hydrogel.

[0042] It should be noted that the hemostatic components mainly consist of at least one of thrombin and chitosan quaternary ammonium salt. Thrombin can rapidly promote blood clotting and reduce postoperative wound bleeding; chitosan quaternary ammonium salt not only has a hemostatic effect but also enhances the antibacterial properties of the dressing. Anti-inflammatory drugs can be nonsteroidal anti-inflammatory drugs (NSAIDs) or antibiotics. NSAIDs can effectively relieve wound inflammation and reduce patient pain; antibiotics can prevent postoperative wound infection and reduce the risk of complications. All added ingredients have undergone rigorous screening, have good biocompatibility, and can synergize with the hydrogel without affecting the dressing's anti-adhesion, repair, and controllable degradation functions.

[0043] Example 1: Medium-crosslinked general-purpose crosslinked sodium hyaluronate intrauterine anti-adhesion gel

[0044] 1. Prescription Composition

[0045] 32g of graded cross-linked sodium hyaluronate, comprising 22.4g of high molecular weight sodium hyaluronate (1300kDa) and 9.6g of low molecular weight sodium hyaluronate (400kDa) in a mass ratio of 7:3; 10g of recombinant type III humanized collagen; 7g of high degree of deacetylation medical carboxymethyl chitosan; 15g of pharmaceutical grade glycerol; 0.5g of medical grade EDTA-2Na; 0.2g of medical grade natural genipin; and isotonic PBS buffer at pH 7.2, to a final volume of 1000mL.

[0046] 2. Preparation steps

[0047] (1) Preparation of graded crosslinked sodium hyaluronate hydrogel: High molecular weight sodium hyaluronate (1300kDa, 22.4g) and low molecular weight sodium hyaluronate (400kDa, 9.6g) were dissolved in 500mL PBS buffer and stirred until completely dissolved. 0.2g of genipin was added, the pH was adjusted to 7.2, and the mixture was stirred at 30℃ for 30 minutes. The mixture was then allowed to stand for crosslinking for 18 hours to form a three-dimensional network hydrogel with a medium degree of crosslinking. By controlling the crosslinking time and stirring speed, a porous structure with a pore size of 10-100μm was formed inside the hydrogel. Purification: The hydrogel was washed 5 times with sterile PBS for 2 hours each time to remove unreacted genipin.

[0048] (2) Preparation of collagen-chitosan complex solution: Dissolve 10g of recombinant type III humanized collagen and 7g of carboxymethyl chitosan in 200mL PBS, add 15g of glycerol and 0.5g of EDTA-2Na, stir until completely dissolved, and stir at 10℃ for 45 minutes to allow the two to bind through electrostatic interaction or hydrogen bonding.

[0049] (3) Mixing and Shaping: Cut the hydrogel obtained in step (1) into gel microparticles with a particle size of 200-400 μm, and add them to the composite solution in step (2). The volume ratio of hydrogel microparticles to composite solution is 2:1. Gently stir at 15°C for 20 minutes to allow the composite solution to be fully adsorbed into the porous structure and surface of the hydrogel. Add PBS to a total volume of 1000 mL and adjust the viscosity to an injectable fluid state.

[0050] (4) Sterilization and packaging: Sterilize by irradiation (15kGy), dispense into pre-filled syringes under sterile conditions, and store at 2-8℃ away from light.

[0051] 3. Results of full-item testing of finished products

[0052] The product is a colorless, transparent, homogeneous, and fine gel, free of foreign matter and without stratification; its pH value is 7.2; its dynamic viscosity is 45000 mPa·s; it passes sterility testing and has a cytotoxicity level of 0; it is non-sensitizing; it causes no irritation to the uterine mucosa; the residual cross-linking agent is 0.08 μg / g; the complete degradation cycle is 5 weeks; the intrauterine retention time is 86 hours; and the effective rate for preventing intrauterine adhesions is 95.8%. All indicators meet the technical requirements for registered products.

[0053] Example 2: Low-crosslinking degree, fast-release crosslinked sodium hyaluronate intrauterine anti-adhesion gel

[0054] (Suitable for minimally invasive intrauterine procedures such as IUD removal and diagnostic curettage)

[0055] 1. Prescription Composition

[0056] 25g of graded cross-linked sodium hyaluronate, including 17.5g of high molecular weight sodium hyaluronate (1200kDa) and 7.5g of low molecular weight sodium hyaluronate (300kDa); 6g of recombinant type III humanized collagen; 5g of high degree of deacetylation medical carboxymethyl chitosan; 12g of pharmaceutical grade glycerol; 0.5g of medical grade EDTA-2Na; 0.1g of medical grade natural genipin; and isotonic PBS buffer at pH 7.0, to a final volume of 1000mL.

[0057] 2. Preparation steps

[0058] The only difference between the preparation steps and those in Example 1 is in the crosslinking step: the genipin crosslinking standing time is 12 hours, resulting in a low-crosslinking gel matrix. All other preparation steps and process parameters (including mixing, purification, sterilization, etc.) are completely consistent with those in Example 1.

[0059] 3. Finished product testing results

[0060] The complete degradation cycle is 4 weeks; the dynamic viscosity is 32000 mPa·s; the intrauterine retention time is 74 h; the cytotoxicity is grade 0; all indicators meet the technical requirements of the registered product and are suitable for the anti-adhesion needs after minimally invasive intrauterine procedures such as IUD removal and diagnostic curettage.

[0061] Example 3: Highly cross-linked sustained-release cross-linked sodium hyaluronate intrauterine anti-adhesion gel

[0062] (Suitable for large-incision intrauterine procedures such as hysteroscopic electrosurgical resection and separation of severe adhesions)

[0063] 1. Prescription Composition

[0064] 42g of graded cross-linked sodium hyaluronate, including 29.4g of high molecular weight sodium hyaluronate (1500kDa) and 12.6g of low molecular weight sodium hyaluronate (500kDa); 14g of recombinant type III humanized collagen; 9g of high degree of deacetylation medical carboxymethyl chitosan; 18g of pharmaceutical grade glycerol; 0.5g of medical grade EDTA-2Na; 0.3g of medical grade natural genipin; and isotonic PBS buffer at pH 7.4, to a final volume of 1000mL.

[0065] 2. Preparation steps

[0066] The only difference between the preparation steps and those in Example 1 is in the crosslinking step: the genipin crosslinking standing time is 24 hours, resulting in a highly crosslinked gel matrix. All other preparation steps and process parameters are completely consistent with those in Example 1.

[0067] 3. Finished product testing results

[0068] The complete degradation cycle is 6 weeks; the dynamic viscosity is 58000 mPa·s; the intrauterine retention time is 92 hours; it has excellent anti-erosion ability; the cytotoxicity is grade 0; all indicators meet the technical requirements of the registered product and are suitable for the anti-adhesion needs after large-area intrauterine procedures such as hysteroscopic electrocautery and severe adhesion separation.

[0069] By adjusting the ratio of high-molecular-weight to low-molecular-weight sodium hyaluronate (fixed at 7:3, but with different molecular weights) and the degree of cross-linking of genipin (low cross-linking: genipin 0.1g / 1000mL, cross-linking for 12h; medium cross-linking: 0.2g / 1000mL, cross-linking for 18h; high cross-linking: 0.3g / 1000mL, cross-linking for 24h), the degradation cycle can be controlled within the range of 4-6 weeks, matching the physiological repair cycle of the endometrium (approximately 4-6 weeks).

[0070] It should be noted that, in this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0071] The present application and its embodiments have been described above. Such description is not restrictive. In short, if a person skilled in the art is inspired by it and designs a similar structure and embodiment without departing from the spirit of the present application, such design should fall within the protection scope of the present application.

Claims

1. A postoperative endometrial protective and anti-adhesion repair dressing, characterized in that, The dressing is a sterile hydrogel formulation, which comprises graded cross-linked sodium hyaluronate, recombinant type III humanized collagen, and carboxymethyl chitosan. The gradient cross-linked sodium hyaluronate is prepared by cross-linking high molecular weight sodium hyaluronate and low molecular weight sodium hyaluronate with the natural cross-linking agent genipin to form a three-dimensional network hydrogel. The three-dimensional network hydrogel can form a physical isolation barrier on the inner wall of the uterine cavity to prevent the wound surface of the damaged endometrium from contacting the anterior and posterior walls, uterine horns and fallopian tube openings. The recombinant type III humanized collagen and the carboxymethyl chitosan work synergistically to form a physical moisturizing protective film on the damaged endometrial wound, which is used to isolate inflammatory factors and reduce postoperative bleeding and exudation. The gradient cross-linked sodium hyaluronate achieves controllable degradation by adjusting the compounding ratio of high molecular weight sodium hyaluronate and low molecular weight sodium hyaluronate and the degree of cross-linking of genipin. The degradation cycle matches the physiological repair cycle of the endometrium.

2. The postoperative endometrial protection and anti-adhesion repair dressing according to claim 1, characterized in that, The three-dimensional network structure of the gradient crosslinked sodium hyaluronate is porous and is used to load drugs or bioactive factors. The pore size of the porous structure ranges from 10 to 100 μm. The drugs or bioactive factors are loaded inside the porous structure by physical adsorption or encapsulation, and the loading amount accounts for 0.1% to 5.0% of the total mass of the hydrogel.

3. The postoperative endometrial protection and anti-adhesion repair dressing according to claim 1, characterized in that, The mass ratio of high molecular weight sodium hyaluronate to low molecular weight sodium hyaluronate is 1:1 to 5:

1.

4. The postoperative endometrial protection and anti-adhesion repair dressing according to claim 1, characterized in that, The recombinant type III humanized collagen and carboxymethyl chitosan are bound together through electrostatic interaction or hydrogen bonding to form a physical moisturizing protective film on the wound surface.

5. The postoperative endometrial protection and anti-adhesion repair dressing according to claim 1, characterized in that, The hydrogel formulation of the dressing is in an injectable fluid state to accommodate different uterine cavity shapes.

6. The postoperative endometrial protection and anti-adhesion repair dressing according to claim 1, characterized in that, The dressing also includes at least one of a hemostatic component or an anti-inflammatory drug, wherein the hemostatic component or anti-inflammatory drug is dispersed in the three-dimensional mesh hydrogel.

7. The postoperative endometrial protection and anti-adhesion repair dressing according to claim 2, characterized in that, The drug includes at least one of antibiotics, anti-inflammatory drugs, and hemostatic drugs, and the bioactive factor includes at least one of epidermal growth factor, fibroblast growth factor, and vascular endothelial growth factor.

8. The postoperative endometrial protection and anti-adhesion repair dressing according to claim 6, characterized in that, The hemostatic component is at least one of thrombin and chitosan quaternary ammonium salt, and the anti-inflammatory drug is a nonsteroidal anti-inflammatory drug or an antibiotic, which is evenly dispersed and does not damage the three-dimensional network structure of the hydrogel.

9. The postoperative endometrial protection and anti-adhesion repair dressing according to claim 1, characterized in that, The mass ratio of the recombinant type III humanized collagen to the carboxymethyl chitosan is 2:1-4:1, and the total mass of the two accounts for 0.5%-2.0% of the total mass of the sterile hydrogel preparation.