Leukocyte-deficient low-pro-inflammatory risk PRP gel as well as preparation method and application thereof

Abstract

The invention provides PRP gel poor in leucocyte and low in pro-inflammatory risk as well as a preparation method and application of the PRP gel, and belongs to the field of PRP gel. The method comprises the following steps: S1, under a high vacuum condition, mixing acrylate resin, a surface modified nano silicon dioxide composite material, polyether modified polysiloxane and polyvinyl pyrrolidone to obtain PRP separation gel; s2, collecting peripheral blood by using a vacuum blood collection tube with a built-in PRP (platelet rich plasma) separation gel, and centrifuging to obtain platelet rich plasma on an interface of the PRP separation gel; s3, mixing and activating the platelet-rich plasma and an initiator to obtain the PRP gel. The precise density gradient is constructed by customizing the thixotropic separation gel, efficient layered isolation of platelets, pro-inflammatory leukocytes and erythrocytes is achieved, the high-concentration platelets are accurately enriched, meanwhile, the leukocyte content is greatly reduced, and therefore PRP products with controllable components and stable effects are achieved, and the repairing requirements of sensitive environments such as uterine cavities are met.

Description

Technical Field

[0001] This application relates to the field of PRP gel technology, and in particular to a PRP gel with low pro-inflammatory risk and anemic leukocytes, its preparation method and application. Background Technology

[0002] Intrauterine adhesions are a common secondary condition following damage to the basal layer of the endometrium, clinically manifesting as amenorrhea, decreased menstrual flow, infertility, or recurrent miscarriage, severely impacting women's reproductive health and quality of life. Currently, hysteroscopic adhesiolysis is the standard surgical procedure for treating this condition; however, postoperative adhesion recurrence, especially in moderate to severe cases, remains a major clinical challenge. Although domestic and international guidelines recommend postoperative physical barrier measures such as intrauterine support balloons and anti-adhesion gels, supplemented with estrogen to promote endometrial regeneration, no biological agents are currently included in routine prevention and treatment programs. This creates a clinical need and space for exploring novel adjuvant therapies.

[0003] In recent years, autologous platelet-rich plasma (PRP), as an autologous biological agent rich in various growth factors, has shown potential application value in the field of tissue repair and regenerative medicine. Multiple clinical studies suggest that local application of PRP after hysteroscopy via intrauterine perfusion or subendometrial injection may help reduce the recurrence rate of intrauterine adhesions, increase endometrial thickness, improve menstrual conditions, and even increase clinical pregnancy rates, providing a new treatment direction for the repair of intrauterine adhesions.

[0004] However, existing PRP preparation technologies suffer from a core deficiency: the inability to precisely control the cellular components of platelet-rich plasma, particularly the difficulty in effectively reducing leukocyte concentration. This results in PRP products with a high risk of pro-inflammatory effects and insufficient stability in clinical application. Since the uterine cavity is a sensitive physiological environment, it places extremely high demands on the safety and compatibility of biological agents. Due to the aforementioned technical deficiencies, existing PRP products are ill-suited to the clinical needs of uterine cavity repair, limiting their widespread application as adjuvant therapy after intrauterine adhesion surgery. Currently, no existing PRP separating gel system can simultaneously achieve high platelet enrichment, low leukocyte residue, and extremely low erythrocyte residue. Therefore, developing a PRP preparation technology that can precisely control cellular components, effectively reduce leukocyte concentration, minimize pro-inflammatory risks, and is suitable for repairing the sensitive environment of the uterine cavity has become a critical issue urgently needing to be addressed in current clinical translation. Summary of the Invention

[0005] This application provides a PRP gel with low pro-inflammatory risk due to anemia of leukocytes, its preparation method, and its application, in order to solve the core technical problems of existing PRP preparation technology, which are high pro-inflammatory risk, unstable clinical application effects, and are particularly unsuitable for repair in sensitive environments such as the uterine cavity, due to the inability to accurately control cell components, especially the inability to effectively reduce leukocyte concentration.

[0006] In a first aspect, embodiments of this application provide a method for preparing a PRP gel with low pro-inflammatory risk and anemia of leukocytes, the method comprising the following steps: S1. Under high vacuum conditions, acrylate resin and surface-modified nano-silica composite material are dispersed and mixed in multiple steps, then polyether-modified polysiloxane and polyvinylpyrrolidone are added and dispersed and mixed in multiple steps to obtain PRP separating adhesive. S2. Peripheral blood is collected using a vacuum blood collection tube containing the PRP separating gel. After centrifugation, platelet-rich plasma is obtained on the interface of the PRP separating gel. S3. The platelet-rich plasma is mixed with an initiator and activated to obtain PRP gel; The mass ratio of the acrylate resin, the surface-modified nano-silica composite material, the polyether-modified polysiloxane, and the polyvinylpyrrolidone is 100:(8-10):(0.8-1.2):(0.5-1.0). The acrylate resin is polymerized from the following monomers in parts by weight: 91-93 parts butyl acrylate, 2.5-3.5 parts methyl methacrylate, 1.5-2.5 parts styrene, and 0.5-1.0 parts glycidyl methacrylate. The platelet-rich plasma has the following components: platelet concentration is 3.0 to 4.0 times the baseline whole blood concentration, white blood cell concentration is 0.40 to 0.60 times the baseline whole blood concentration, and red blood cell concentration is 0.005 to 0.015 times the baseline whole blood concentration.

[0007] Optionally, the preparation method of the acrylate resin includes the following steps: S111. The butyl acrylate, the methyl methacrylate, the styrene, and the glycidyl methacrylate are added to dimethylformamide to obtain a monomer mixture; S112. Dissolve azobisisobutyronitrile in dimethylformamide to obtain an initiator solution; S113. Heat the monomer mixture to 65-75°C, then add the initiator solution dropwise, controlling the dropwise addition time to be 4-6 hours. After the dropwise addition is completed, keep it at 65-75°C for 1-2 hours to obtain the reaction solution. S114. The reaction solution is subjected to heated and vacuum distillation to remove the solvent and unreacted monomers, thereby obtaining the acrylate resin.

[0008] Optionally, the mass of the azobisisobutyronitrile is 2.0 to 3.0% of the mass of the butyl acrylate.

[0009] Optionally, the preparation method of the surface-modified nano-silica composite material includes the following steps: S121. Hollow mesoporous silica nanospheres were dispersed in anhydrous ethanol, a silane coupling agent was added, and the mixture was refluxed at 60-80°C for 4-6 hours. After the reaction was completed, the nanospheres were separated, washed, and dried to obtain epoxy-functionalized hollow mesoporous silica. S122. The epoxy-functionalized hollow mesoporous silica is dispersed in an alkaline buffer solution, and then amino-terminated polyethylene glycol and sodium dextran sulfate are added sequentially. The reaction is carried out at 25-45°C for 8-12 hours. After the reaction is completed, the solid product is separated, washed, and dried to obtain the surface-modified nano silica composite material.

[0010] Optionally, the density of the hollow mesoporous silica nanospheres is 0.88~0.90 g / cm³. 3 ; The mass ratio of the silane coupling agent to the hollow mesoporous silica nanospheres is (0.1-0.2):1; The mass ratio of the epoxy-functionalized hollow mesoporous silica, the amino-terminated polyethylene glycol, and the sodium dextran sulfate is 1:(0.1-0.3):(0.05-0.25).

[0011] Optionally, the preparation method of the hollow mesoporous silica nanospheres includes the following steps: S121a. Polystyrene template spheres are dispersed in an alcohol-water mixed solvent, then ammonia catalyst is added, and after stirring evenly, tetraethyl orthosilicate is slowly added dropwise. The silicon source hydrolysis reaction is carried out at 25-35℃ for 6-12 hours. S121b After the reaction is complete, centrifugation is performed to obtain polystyrene@silica core-shell structured microspheres. The polystyrene template is removed by washing with an organic solvent to obtain the intermediate product. S121c. The intermediate product is calcined at 500-600°C for 2-4 hours to obtain hollow mesoporous silica nanospheres. The polystyrene template spheres have a particle size of 200–400 nm. The mass ratio of the tetraethyl orthosilicate to the polystyrene template sphere is (1.5-2.5):1.

[0012] Optionally, the preparation method of the polyether-modified polysiloxane includes the following steps: S131. Dissolve hydrogen-containing silicone oil, allyl polyoxyethylene methyl-terminated polyether and chloroplatinic acid in isopropanol solution in organic solvent, stir evenly under inert gas protection to obtain reaction solution; S132. Heat the reaction solution to 80-95°C and react for 4-8 hours; S133. After the reaction is complete, the reaction system is subjected to vacuum distillation to remove the organic solvent and unreacted monomers, thereby obtaining the polyether-modified polysiloxane. The molar ratio of Si-H bonds in the hydrogen-containing silicone oil to C=C bonds in the allyl polyoxyethylene methyl-terminated polyether is 1:(1.0-1.2). The mass of the chloroplatinic acid is 0.005 to 0.010% of the mass of the hydrogen-containing silicone oil.

[0013] Optionally, the initiator is thrombin, and the volume ratio of the platelet-rich plasma to the initiator is 9:1; The centrifugal force is 1500-2000g, and the centrifugation time is 10-15min.

[0014] Secondly, embodiments of this application provide a PRP gel prepared by the method described in any one of the first aspects, wherein the PRP gel is formed by activating platelet-rich plasma and thrombin in a volume ratio of 9:1.

[0015] Thirdly, embodiments of this application provide the application of the PRP gel described in the second aspect in the preparation of a drug for post-hysteroscopic repair and prevention of intrauterine adhesions.

[0016] The technical solutions provided in this application have the following advantages compared with the prior art: This application provides a method for preparing PRP gel with low pro-inflammatory risk and anemic leukocytes. By constructing a precisely regulated separation system and establishing clear component control standards, it specifically addresses the core issues of existing PRP preparation technologies. The specific implementation path is as follows: First, this application designs a functionally synergistic PRP separating gel formulation, providing a foundation for precise control of cell components. Acrylic resin, surface-modified nano-silica composite material, polyether-modified polysiloxane, and polyvinylpyrrolidone are mixed at a mass ratio of 100:(8–10):(0.8–1.2):(0.5–1.0). The acrylate resin is polymerized from butyl acrylate, methyl methacrylate, styrene, and glycidyl methacrylate in a specific ratio, and its molecular structure endows the separating gel with suitable density and mechanical properties. The surface-modified nano-silica composite material further optimizes the density matching of the separating gel, while reducing non-specific adsorption of leukocytes through its surface properties. The polyether-modified polysiloxane and polyvinylpyrrolidone synergistically optimize the interfacial properties and biocompatibility of the separating gel, avoiding abnormal adhesion between cells and the separating gel surface, thus creating conditions for effectively reducing leukocyte concentration from the formulation level.

[0017] Secondly, precise separation of cellular components is achieved through a standardized separation process. Peripheral blood is collected using vacuum blood collection tubes with built-in PRP separating gel. After centrifugation, the density gradient effect of the separating gel causes platelet-rich plasma to accumulate above the separating gel interface, while white blood cells and red blood cells, which have higher densities, are effectively blocked below the separating gel. The density characteristics of the separating gel and the interface design work synergistically to reduce the penetration and retention of white blood cells into platelet-rich plasma, ensuring that the components of platelet-rich plasma strictly meet the preset standards: white blood cell concentration is controlled at 0.40–0.60 times the baseline concentration of whole blood, while ensuring that the platelet concentration is 3.0–4.0 times the baseline concentration of whole blood and the red blood cell concentration is 0.005–0.015 times the baseline concentration of whole blood. This achieves precise control of cellular components at the process level.

[0018] Finally, clearly defined component standards directly reduce the pro-inflammatory risk of PRP products and improve the stability of clinical applications. By effectively reducing leukocyte concentration, the source of pro-inflammatory cytokine release is reduced, while extremely low erythrocyte residue avoids hemolysis-related inflammatory triggers, fundamentally reducing the pro-inflammatory risk of PRP products. Standardized formulation and separation processes ensure the consistency of platelet-rich plasma components, avoiding instability in clinical application effects caused by fluctuations in cell components. Its balance of low pro-inflammatory properties and high bioactivity is perfectly suited to the repair needs of sensitive environments such as the uterine cavity, solving the problem that existing technologies are not suitable for such scenarios. Attached Figure Description

[0019] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0020] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 A schematic flowchart illustrating the preparation method of the PRP gel with low pro-inflammatory risk and anemic leukocytes provided in this application embodiment; Figure 2 This is a physical image of platelet-rich plasma provided in Example 1 of this application; Figure 3 This is a photograph of the PRP gel provided in Example 1 of this application; Figure 4 A physical image of the PRP gel spray gun provided in the embodiments of this application; Figure 5 Intraoperative image of the PRP gel provided in Example 1 of this application in clinical case 1; Figure 6 Intraoperative image of the PRP gel provided in Example 1 of this application in clinical case 2. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0023] Figure 1 This is a schematic flowchart illustrating the preparation method of the PRP gel with low pro-inflammatory risk and low leukocyte count provided in the embodiments of this application.

[0024] like Figure 1 As shown in the embodiments of this application, a method for preparing a PRP gel with low pro-inflammatory risk and anemia of leukocytes is provided. The method includes the following steps: S1. Under high vacuum conditions, acrylate resin and surface-modified nano-silica composite material are dispersed and mixed in multiple steps, then polyether-modified polysiloxane and polyvinylpyrrolidone are added and dispersed and mixed in multiple steps to obtain PRP separating adhesive. S2. Peripheral blood is collected using a vacuum blood collection tube with built-in PRP separating gel. After centrifugation, platelet-rich plasma is obtained on the interface of the PRP separating gel. S3. Platelet-rich plasma is mixed with an initiator and activated to obtain PRP gel; The mass ratio of acrylate resin, surface-modified nano-silica composite material, polyether-modified polysiloxane, and polyvinylpyrrolidone is 100:(8-10):(0.8-1.2):(0.5-1.0). By weight, the acrylate resin is polymerized from the following monomers: 91-93 parts butyl acrylate, 2.5-3.5 parts methyl methacrylate, 1.5-2.5 parts styrene, and 0.5-1.0 parts glycidyl methacrylate. The components of platelet-rich plasma meet the following requirements: platelet concentration is 3.0 to 4.0 times the baseline whole blood concentration, white blood cell concentration is 0.40 to 0.60 times the baseline whole blood concentration, and red blood cell concentration is 0.005 to 0.015 times the baseline whole blood concentration.

[0025] In some embodiments, the initiator is thrombin, and the volume ratio of platelet-rich plasma to initiator is 9:1; The centrifugal force is 1500–2000 g, and the centrifugation time is 10–15 min.

[0026] The core of the PRP gel preparation method provided in this application lies in the meticulous design at the molecular level to construct a PRP separation gel system that enables efficient and precise cell separation and exhibits excellent biocompatibility. This system can stably and reproducibly prepare standard-compliant PRP, providing an optimal solution for sensitive clinical applications such as hysteroscopic postoperative repair.

[0027] The preparation of PRP separating gel (step S1) is the foundation of the entire system. Its core is to regulate the physicochemical properties and biocompatibility of the separating gel through the molecular interactions of each component.

[0028] Acrylic resins serve as the continuous phase framework of PRP (Polyurethane Resin) separating adhesives. Their molecular structure is formed by the polymerization of monomers in specific mass fractions, and the ratio of each monomer directly determines the core physicochemical properties of the separating adhesive. Butyl acrylate, comprising 91–93 parts, provides a long alkyl chain structure, endowing the acrylic resin polymer with excellent flexibility and a viscosity of approximately 1.08 g / cm³. 3 The basic density of the resin, due to its molecular properties, allows the separating gel to undergo moderate deformation under centrifugal force, smoothly moving to the target density layer and laying the physical basis for density gradient separation. Methyl methacrylate (MMA), comprising 2.5–3.5 parts, forms a rigid α-methyl group that physically entangles with the long chain of butyl acrylate, creating a "rigid-flexible" interpenetrating network structure. This significantly improves the resin's modulus and tear resistance, preventing the separating gel from being crushed or penetrated by the dense red blood cell layer under high-speed centrifugation, which is crucial for achieving low red blood cell residue. Styrene (1.5–2.5 parts) enhances the resin's hydrophobicity by introducing a rigid benzene ring, reducing the non-specific adsorption of hydrophilic leukocytes and platelets on the separating gel surface through molecular-level hydrophobic interactions, contributing to the achievement of the "leukopenia" target. Simultaneously, the rigidity of the benzene ring further supplements the material's mechanical strength. Glycidyl methacrylate (GMA), comprising 0.5–1.0 parts, is a key functional monomer with highly reactive epoxy groups on its side chains. During the formulation and subsequent processing of the separating adhesive, the epoxy group can undergo an efficient ring-opening reaction with the amino groups (derived from amino-terminated polyethylene glycol) grafted onto the surface of the surface-modified nano-silica composite material under mild conditions, forming a strong covalent bond. This achieves an indirect and stable chemical bridge between the organic resin matrix and the inorganic nanofiller through organic molecular chains, significantly enhancing the interfacial bonding force and fundamentally solving the problem of easy agglomeration and detachment of nanoparticles in the resin matrix, ensuring the uniformity and long-term stability of the composite material.

[0029] Surface-modified nano-silica composites achieve precise control of separator density and optimization of interfacial functions through molecular structure design. These composites, with their unique hollow mesoporous structure, achieve a density of approximately 0.88–0.90 g / cm³. 3 The low apparent density of PRP (Polymer Propane Resin) is the physical basis for controlling the overall density of the PRP separating adhesive. During the multi-step dispersion and mixing process, resin oligomers and additive molecules can partially penetrate into its hierarchical channels, forming a dense organic-inorganic interfacial hybrid phase. This process not only enhances the interfacial bonding between the filler and the resin matrix, but more importantly, although the effective density of this composite filler unit in the material is slightly higher than its original apparent density due to the penetration of organic matter, it is still significantly lower than that of solid silica and stably lower than that of the acrylic resin matrix. By controlling the addition ratio of such low effective density fillers (mass ratio 8–10:100), the composite density of the PRP separating adhesive can be precisely titrated to 1.03–1.07 g / cm³. 3 This narrow and ideal target range satisfies the density gradient requirements for centrifugation. During centrifugation, the separating gel effectively blocks leukocytes from a physical density perspective, providing a crucial physical basis for obtaining "leukopenic" platelet-rich plasma (PRP). Simultaneously, its surface covalently fixes amino-terminated polyethylene glycol and sodium dextran sulfate to form a biomimetic anti-adhesion coating, constructing a dual "electrostatic-hydration" protective layer at the nanoscale: the sulfonate group in the sodium dextran sulfate molecule carries a strong negative charge under physiological conditions, generating electrostatic repulsion with similarly negatively charged platelets and leukocytes, reducing cell adhesion chemically; the amino-terminated polyethylene glycol chains form a dynamic hydration layer through a unique molecular conformation, producing a strong steric hindrance effect, physically blocking the non-specific adsorption of proteins and cells. The synergistic effect of both enhances anti-adhesion, which is the core of achieving "leukopenic" and "low platelet activation." Furthermore, the mass ratio of this composite material to acrylic resin (8-10):100 ensures both precise density control and effective coverage of the anti-adhesion coating.

[0030] Polyether-modified polysiloxane and polyvinylpyrrolidone, as key functional additives, together optimize the processing performance, rheological properties and final biointerface performance of PRP separating gel through precise molecular-level design and interaction.

[0031] In this system, polyether-modified polysiloxane plays a crucial role in both interface regulation and rheological modification. The hydrophobic segments of the polysiloxane in its molecular structure anchor to the acrylate resin phase, while the hydrophilic segments of the polyether extend onto the system surface, acting as traditional surfactants to significantly reduce surface tension during processing, eliminate bubbles, and achieve a smooth interface. More importantly, the ether oxygen atoms abundant in its polyether segments can form a broad and dynamic multi-layered hydrogen bond network with ester groups in the resin matrix, silanol groups on the surface of nano-silica, and amino groups grafted onto the modified silica surface. This hydrogen bond network endows the separating gel with excellent thixotropic properties: under static or low-shear conditions, the hydrogen bond network provides sufficient structural strength to maintain the morphological stability of the separating gel and prevent component sedimentation or stratification; under the high shear force of centrifugation, the hydrogen bonds can reversibly dissociate, increasing the fluidity of the separating gel, allowing it to move smoothly and uniformly to the target density layer between plasma and blood cells, and rapidly rebuilding the network structure after centrifugation, stabilizing the formed high-quality separation interface. Meanwhile, the lubricating layer formed by its hydrophilic segments at the blood contact interface helps to further reduce non-specific activation and adhesion of platelets. A mass ratio of (0.8~1.2):100 can precisely balance its interface optimization, rheological regulation effects and its impact on the overall density of the separating gel.

[0032] Polyvinylpyrrolidone (PVP), through its highly polar carbonyl group (C=O) in its molecular chain, forms dense and stable multiple hydrogen bonds with the hydroxyl groups at the ends of the amino-terminated polyethylene glycol (NH2-PEG) chains covalently grafted with glycidyl methacrylate, as well as other polar groups on the surface of the nanocomposite material. This allows PVP to be effectively anchored and enriched at the outermost interface of the composite system, thereby constructing a robust and durable hydrophilic brush-like coating in situ. This coating can maximally resist the initial adsorption of plasma proteins (a prerequisite for cell adhesion), synergistically with the biomimetic anti-adhesion coating provided by the surface-modified nano-silica composite material (such as the electrostatic repulsion of sodium dextran sulfate), ensuring excellent bioinertness at the outermost interface of the separating gel. Simultaneously, the long molecular chain of PVP provides effective steric hindrance between the nano-silica particles and the resin matrix, preventing nanoparticle aggregation, complementing the chemical anchoring effect of glycidyl methacrylate, and jointly ensuring the uniformity and long-term stability of the density barrier. A mass ratio of (0.5~1.0):100 can prevent the hydrophilic coating from being too thick, affecting the core density of the separating gel, or too thin, causing the anti-adhesion function to fail.

[0033] The above-mentioned four components—acrylate resin, surface-modified nano-silica composite material, polyether-modified polysiloxane, and polyvinylpyrrolidone—are compounded in a precise mass ratio of 100:(8-10):(0.8-1.2):(0.5-1.0). Through multi-level intermolecular interactions such as covalent bond connection, hydrogen bond network, physical entanglement, and steric hindrance, they jointly construct a structurally stable, rheologically controllable, and interfacially functional PRP separating gel system.

[0034] The core of step S2 is to achieve precise separation of platelet-rich plasma (PRP) through the synergistic effect of centrifugation and the molecular structure characteristics of the separating gel. After collecting peripheral blood using vacuum blood collection tubes with built-in PRP separating gel, the blood is processed at 1500–2000 g for 10–15 min. This centrifugation parameter is highly matched to the molecular structure characteristics of the separating gel: the 1500–2000 g centrifugation force drives the separating gel to the target density layer in the blood, while preventing the separating gel from being penetrated by the erythrocyte layer due to excessive centrifugation force (thanks to the reinforcing effect of the interpenetrating network structure of the acrylate resin and the surface-modified nano-silica composite material); the 10–15 min centrifugation time ensures complete separation of blood components according to the density gradient, avoiding incomplete separation due to insufficient time and preventing non-specific platelet activation due to excessive time (thanks to the bio-inert coating on the surface of the separating gel). During centrifugation, the separating gel, with a density of 1.03–1.07 g / cm³, achieves a separation density of 1.03–1.07 g / cm³. 3 Due to its density properties, it precisely adheres to form a stable isolation interface between plasma and blood cells. Through the molecular interaction of the surface biomimetic anti-adhesion coating and the polyvinylpyrrolidone coating, the adsorption and retention of leukocytes and platelets on the surface of the separating gel are reduced. Finally, platelet-rich plasma that meets specific component requirements is obtained on the separating gel interface: the platelet concentration is 3.0 to 4.0 times the whole blood baseline concentration (achieved through density gradient enrichment and low adsorption characteristics), the leukocyte concentration is 0.40 to 0.60 times the whole blood baseline concentration (achieved through hydrophobic interaction and electrostatic-hydration synergistic anti-adhesion), and the erythrocyte concentration is 0.005 to 0.015 times the whole blood baseline concentration (thanks to the mechanical strength and sharp interface of the separating gel).

[0035] Step S3 activates the gel through the molecular interaction between platelet-rich plasma and the initiator, wherein the initiator is thrombin, and the volume ratio of platelet-rich plasma to thrombin is set at 9:1. This ratio is based on the molecular-level regulation of activation efficiency: as a specific activator, thrombin can recognize and bind to coagulation factors in platelet-rich plasma, triggering platelet degranulation and release of growth factors, while inducing fibrinogen to be converted into a fibrin network. The 9:1 volume ratio ensures that the thrombin concentration is sufficient to initiate the activation reaction, while avoiding excessive thrombin which could lead to excessive cross-linking of the gel or trigger additional inflammatory reactions. During activation, the high concentration of platelets in platelet-rich plasma, triggered by thrombin, orderly releases growth factors (such as platelet-derived growth factor and transforming growth factor). These growth factors are fixed by the fibrin network, forming a PRP gel that combines bioactivity and structural stability. Meanwhile, the low concentration of leukocytes in platelet-rich plasma (0.40–0.60 times the baseline whole blood concentration) reduces the release of pro-inflammatory cytokines (such as interleukin-1β and tumor necrosis factor-α), and the extremely low concentration of erythrocytes (0.005–0.015 times the baseline whole blood concentration) avoids oxidative stress and inflammatory responses caused by hemoglobin, iron ions, and other substances after hemolysis, ultimately forming a PRP gel with low pro-inflammatory risk and anemic leukocytes.

[0036] In some implementations, step S1 specifically includes: Raw material preparation: Acrylic resin, surface-modified nano-silica composite material, polyether-modified polysiloxane and polyvinylpyrrolidone are provided; Primary dispersion: The acrylate resin and the surface-modified nano silica composite material are placed in a planetary disperser and mixed at a stirring speed of 10-20 rpm for 10-20 min under a vacuum of not less than -0.096 MPa. Then, the mixture is dispersed at a stirring speed of 30-40 rpm and a dispersion speed of 200-300 rpm for 60-80 min. Final dispersion and degassing: Polyether-modified polysiloxane and polyvinylpyrrolidone are added to the mixture after primary dispersion. Under a vacuum of not less than -0.096 MPa, the mixture is stirred at a speed of 10-20 rpm for 10-20 min as in step three. Then, it is dispersed at a speed of 30-40 rpm and a dispersion speed of 100-200 rpm for 60-80 min as in step four to obtain the PRP separating gel.

[0037] In some embodiments, the preparation method of acrylate resins includes the following steps: S111. Butyl acrylate, methyl methacrylate, styrene, and glycidyl methacrylate are added to dimethylformamide to obtain a monomer mixture; S112. Dissolve azobisisobutyronitrile in dimethylformamide to obtain an initiator solution; S113. Heat the monomer mixture to 65-75℃, then add the initiator solution dropwise, controlling the dropwise addition time to 4-6 hours. After the dropwise addition is complete, keep the mixture at 65-75℃ for 1-2 hours to obtain the reaction solution. S114. The reaction solution is heated and distilled under reduced pressure to remove the solvent and unreacted monomers, yielding an acrylate resin.

[0038] In some embodiments, the mass of azobisisobutyronitrile is 2.0 to 3.0% of the mass of butyl acrylate.

[0039] It should be noted that the preparation of acrylate resins is precisely controlled through solution polymerization to ensure that the product possesses the mechanical properties and functional groups required for the separating gel.

[0040] Steps S111 and S112 are pretreatments of the reaction system. Four monomers, namely butyl acrylate, methyl methacrylate, styrene, and glycidyl methacrylate, are added to dimethylformamide to form a homogeneous monomer mixture, ensuring that each monomer participates in the polymerization reaction in a preset ratio. Azobisisobutyronitrile is dissolved in dimethylformamide to prepare an initiator solution, so that the initiator is uniformly dispersed, laying the foundation for subsequent uniform polymerization.

[0041] Step S113 is the core polymerization process, where the monomer mixture is heated to 65–75°C. This temperature range promotes the stable decomposition of azobisisobutyronitrile (AIBN) to generate free radicals, providing the initiation conditions for chain polymerization. A 4–6 hour initiator dropwise addition process allows for precise control of the free radical generation rate, avoiding excessively wide molecular weight distribution or explosive polymerization caused by concentrated exothermic reactions. The 1–2 hour holding period after dropwise addition ensures complete monomer conversion, forming a copolymer with a suitable molecular weight and stable structure, guaranteeing a balance between the resin's flexibility and mechanical strength.

[0042] Step S114 is a post-purification treatment. Dimethylformamide solvent and unreacted monomers in the system are removed by heating and vacuum distillation. This not only improves the purity of the product, but also completely removes potentially irritating residual monomers, thus ensuring the biosafety of the final PRP gel.

[0043] The mass of azobisisobutyronitrile is set to 2.0-3.0% of the mass of butyl acrylate. This ratio can provide a suitable concentration of free radicals, effectively control the molecular weight of the polymer, and enable the resin to have both good processing fluidity and excellent mechanical stability, so as to meet the deformation requirements and structural support of the separating gel during centrifugation.

[0044] In some embodiments, the preparation method of the surface-modified nano-silica composite material includes the following steps: S121. Hollow mesoporous silica nanospheres were dispersed in anhydrous ethanol, a silane coupling agent was added, and the mixture was refluxed at 60-80°C for 4-6 hours. After the reaction was completed, the nanospheres were separated, washed, and dried to obtain epoxy-functionalized hollow mesoporous silica. S122. Epoxy-functionalized hollow mesoporous silica was dispersed in an alkaline buffer solution, followed by the sequential addition of amino-terminated polyethylene glycol and sodium dextran sulfate. The reaction was carried out at 25–45 °C for 8–12 h. After the reaction was completed, the solid product was separated, washed, and dried to obtain a surface-modified nano silica composite material.

[0045] In some embodiments, the density of the hollow mesoporous silica nanospheres is 0.88~0.90 g / cm³. 3 ; The mass ratio of silane coupling agent to hollow mesoporous silica nanospheres is (0.1–0.2):1; The mass ratio of epoxy-functionalized hollow mesoporous silica, amino-terminated polyethylene glycol, and sodium dextran sulfate is 1:(0.1-0.3):(0.05-0.25).

[0046] It should be noted that the preparation of surface-modified nano-silica composite materials involves a two-step functionalization reaction, which endows the nanofillers with precise density and excellent bio-anti-adhesion properties.

[0047] Step S121 achieves epoxy functionalization of the nanosphere surface. Hollow mesoporous silica nanospheres are dispersed in anhydrous ethanol, and a silane coupling agent is added. The mixture is then refluxed at 60–80 °C for 4–6 h. After the ethoxy groups of the silane coupling agent are hydrolyzed, they undergo a condensation reaction with the silanol groups on the nanosphere surface, covalently grafting epoxy groups onto the nanosphere surface. This provides highly reactive chemical anchors for subsequent biomolecule immobilization. This combination of temperature and time ensures that the hydrolysis and condensation reactions proceed fully, resulting in a uniform coating of epoxy functional groups on the nanosphere surface.

[0048] Step S122 constructs a biomimetic anti-adhesion coating. In an alkaline buffer environment, the epoxy groups on the surface of epoxy-functionalized hollow mesoporous silica undergo a highly efficient ring-opening reaction with the primary amino groups at the ends of amino-terminated polyethylene glycol and sodium dextran sulfate molecules, achieving covalent fixation of the two bioactive molecules. The reaction temperature of 25–45°C ensures the reaction rate while avoiding the inactivation of biomolecules due to high temperatures; the reaction time of 8–12 hours ensures the functional groups fully combine, forming a hybrid brush coating that combines steric hindrance and electrostatic repulsion, actively resisting blood cell adhesion.

[0049] The mass ratio of silane coupling agent to hollow mesoporous silica nanospheres is (0.1–0.2):1. This ratio ensures that the surface of the nanospheres is fully covered, providing sufficient epoxy functional groups to meet the subsequent grafting requirements. The mass ratio of epoxy-functionalized hollow mesoporous silica, amino-terminated polyethylene glycol, and sodium dextran sulfate is 1:(0.1–0.3):(0.05–0.25). This ratio allows the two biomolecules to achieve the optimal grafting density and ratio on the nanosurface, forming a synergistic anti-adhesion effect and enhancing the separation effect of leukopenic cells.

[0050] In some embodiments, the preparation method of hollow mesoporous silica nanospheres includes the following steps: S121a. Polystyrene template spheres are dispersed in an alcohol-water mixed solvent, then ammonia catalyst is added, and after stirring evenly, tetraethyl orthosilicate is slowly added dropwise. The silicon source hydrolysis reaction is carried out at 25-35℃ for 6-12 hours. S121b After the reaction is complete, centrifugation is performed to obtain polystyrene@silica core-shell structured microspheres. The polystyrene template is removed by washing with an organic solvent to obtain the intermediate product. S121c, The intermediate product is calcined at 500-600℃ for 2-4 hours to obtain hollow mesoporous silica nanospheres; The particle size of the polystyrene template spheres is 200–400 nm. The mass ratio of tetraethyl orthosilicate to polystyrene template spheres is (1.5–2.5):1.

[0051] It should be noted that the hollow mesoporous silica nanospheres were prepared by precisely controlling the structure using a template method, providing a basic framework for subsequent functionalization.

[0052] Step S121a employs a hard template method to construct the core-shell structure. Polystyrene template spheres with a particle size of 200–400 nm are dispersed in an alcohol-water mixed solvent. After adding ammonia as a catalyst, tetraethyl orthosilicate is slowly added dropwise, and a silicon source hydrolysis reaction is carried out at 25–35 °C for 6–12 h. The particle size of the polystyrene template spheres directly determines the inner diameter of the final hollow spheres. The mass ratio of tetraethyl orthosilicate to polystyrene template spheres is (1.5–2.5):1, which synergistically controls the thickness of the silica shell. The mild reaction temperature of 25–35 °C and the reaction time of 6–12 h ensure that tetraethyl orthosilicate is slowly and uniformly hydrolyzed and deposited, forming complete and uniform polystyrene@silica core-shell structured microspheres.

[0053] Steps S121b and S121c complete template removal and structural solidification. The polystyrene template is removed by washing with organic solvent to obtain an intermediate product with a hollow mesoporous structure. The intermediate product is then calcined at 500-600℃ for 2-4 hours. This process can thoroughly remove residual organic matter and densify the amorphous silica shell, significantly improving the mechanical strength and structural stability of the nanospheres, enabling them to withstand the mechanical stress during subsequent modification reactions and centrifugation.

[0054] In some embodiments, the preparation method of polyether-modified polysiloxane includes the following steps: S131. Dissolve hydrogen-containing silicone oil, allyl polyoxyethylene methyl-terminated polyether and chloroplatinic acid in isopropanol solution in organic solvent, stir evenly under inert gas protection to obtain reaction solution; S132. Heat the reaction solution to 80-95℃ and react for 4-8 hours; S133. After the reaction is complete, the reaction system is subjected to vacuum distillation to remove organic solvents and unreacted monomers, and polyether-modified polysiloxane is obtained. The molar ratio of Si-H bonds in hydrogen-containing silicone oil to C=C bonds in allyl polyoxyethylene methyl-terminated polyether is 1:(1.0~1.2). The mass of chloroplatinic acid is 0.005% to 0.010% of the mass of the hydrogen-containing silicone oil.

[0055] It should be noted that the preparation of polyether-modified polysiloxane is achieved through a hydrosilylation reaction, synthesizing a high-performance leveling agent with both hydrophobic and hydrophilic properties.

[0056] Step S131 involves setting up the reaction system by dissolving hydrogen-containing silicone oil, allyl polyoxyethylene methyl-terminated polyether, and an isopropanol solution of chloroplatinic acid in an organic solvent and stirring until homogeneous under inert gas protection. Inert gas protection prevents chloroplatinic acid catalyst deactivation due to oxidation, ensuring catalytic efficiency; the uniform mixing of all components provides sufficient contact conditions for the hydrosilylation reaction.

[0057] Step S132 is the core reaction stage, where the reaction solution is heated to 80-95°C and reacted for 4-8 hours. This temperature range is the optimal window for the hydrosilylation reaction catalyzed by chloroplatinic acid, which can promote the efficient reaction between the Si-H bonds in the hydrogen-containing silicone oil and the C=C double bonds in the allyl polyoxyethylene methyl-terminated polyether, thereby achieving precise grafting of polyether segments onto the polysiloxane skeleton. The reaction time of 4-8 hours ensures that the bonding reaction proceeds fully, improving the grafting efficiency.

[0058] Step S133 is a purification process, in which organic solvents and unreacted monomers are removed by vacuum distillation to obtain a high-purity polyether-modified polysiloxane product, thus avoiding the influence of impurities on the interface performance of the subsequent separating gel.

[0059] The molar ratio of Si-H bonds in the hydrogen-containing silicone oil to C=C bonds in allyl polyoxyethylene methyl-terminated polyether is set to 1:(1.0-1.2), with a slight excess of allyl polyether. This ensures complete reaction of Si-H bonds in the hydrogen-containing silicone oil, improves grafting efficiency, and avoids residual Si-H bonds from causing subsequent side reactions. The mass of chloroplatinic acid is 0.005-0.010% of the mass of the hydrogen-containing silicone oil. This trace amount can efficiently catalyze the reaction, control costs, and reduce the impact of metal residues on the color and stability of the product.

[0060] Based on a general inventive concept, embodiments of this application provide a PRP gel prepared by any one of the methods in the first aspect, wherein the PRP gel is activated by platelet-rich plasma and thrombin in a volume ratio of 9:1.

[0061] This application prepares a PRP gel with low pro-inflammatory risk and low leukocyte count. The core of this method lies in the construction of an integrated system of "precise density separation - active biological anti-adhesion - targeted component enrichment" through precise molecular-level design and synergistic regulation of process parameters. Each step is progressive and synergistic, reducing leukocyte residue and pro-inflammatory risk from the source, while ensuring efficient platelet enrichment.

[0062] Precise density control of the separating gel is the physical basis for achieving the separation of leukopenic cells. Acrylic resins are used as the separating gel matrix, with butyl acrylate (91-93 parts) providing the base density and a surface-modified nano-silica composite material (density 0.88-0.90 g / cm³). 3 The density supplementation ensures that the density of the entire PRP separating gel precisely matches the critical region between plasma and blood cells. Under centrifugal force of 1500-2000g, the separating gel can quickly move to the target density layer, forming a sharp and stable isolation interface. This precisely separates the lower density platelet-rich plasma from the higher density white blood cells and red blood cells, reducing the infiltration of white blood cells and red blood cells into platelet-rich plasma from a physical perspective, thus laying the structural foundation for "leukopenia".

[0063] The multi-layered bio-anti-adhesion design of the separating gel is the core mechanism for reducing leukocyte retention. The surface-modified nano-silica composite material, after being grafted with epoxy groups using a silane coupling agent, further immobilizes amino-terminated polyethylene glycol and sodium dextran sulfate, forming a dual "electrostatic-hydration" protective layer: the sulfonate group of sodium dextran sulfate carries a strong negative charge, generating electrostatic repulsion with similarly negatively charged leukocytes and platelets, actively driving the cells away; the dynamic hydration layer formed by the amino-terminated polyethylene glycol generates a steric hindrance effect, physically preventing contact between cells and the separating gel surface. Meanwhile, the hydrophobic structure introduced by the styrene monomer in the acrylate resin can reduce the non-specific adsorption of hydrophilic leukocytes; the epoxy groups of polyvinylpyrrolidone and glycidyl methacrylate are covalently grafted to form a hydrophilic brush-like coating on the surface of the separating gel, which resists the initial adsorption of plasma proteins (protein adsorption is a prerequisite for cell adhesion). This works synergistically with the biomimetic anti-adhesion coating to reduce the retention of leukocytes on the surface of the separating gel from both chemical and physical levels, ensuring that the leukocyte concentration in platelet-rich plasma after separation is only 0.40 to 0.60 times that of the whole blood baseline concentration.

[0064] Precise control of process parameters and synergistic component management are key to reducing the risk of pro-inflammatory reactions. Centrifugation time is set at 10–15 minutes to ensure complete separation of blood components according to their density gradients while avoiding non-specific platelet activation due to excessive centrifugation. Platelet-rich plasma is activated with thrombin at a 9:1 volume ratio, ensuring efficient gel formation while preventing excessive thrombin from triggering additional inflammatory responses. The resulting platelet-rich plasma exhibits significantly reduced white blood cell concentration and red blood cell concentration controlled at 0.005–0.015 times the baseline whole blood concentration. This extremely low red blood cell residue avoids oxidative stress and inflammatory responses caused by hemoglobin and iron ions after hemolysis. Meanwhile, the platelet concentration reaches 3.0–4.0 times the baseline whole blood concentration, enabling sufficient release of growth factors (such as platelet-derived growth factor and transforming growth factor) to meet tissue repair needs.

[0065] In summary, this application achieves physical separation through precise density control of the separating gel, reduces leukocyte retention through multiple anti-adhesion designs, and ensures component purity through process parameter control. The synergistic effect of these three factors results in platelet-rich plasma exhibiting an optimized composition of "high platelets, low leukocytes, and extremely low erythrocytes," thereby reducing the release sources and inflammatory triggers of pro-inflammatory cytokines (such as interleukin-1β and tumor necrosis factor-α) from the source, ultimately preparing a PRP gel with low leukocyte risk and low pro-inflammatory risk.

[0066] Based on a general inventive concept, embodiments of this application provide the application of PRP gel in the preparation of a drug for post-hysteroscopic repair and prevention of intrauterine adhesions.

[0067] The reason why the PRP gel of this application can be used to prepare drugs for post-hysteroscopic repair and prevention of intrauterine adhesions is that its optimized component characteristics and bioactive functions are highly compatible with the pathological repair needs after hysteroscopic surgery. Through the synergistic effect of "promoting tissue regeneration, inhibiting excessive inflammation, and physical barrier protection", it can accurately solve the core pain points of incomplete endometrial repair and intrauterine adhesions after surgery.

[0068] The core repair requirement after hysteroscopy is the rapid reconstruction of the endometrial wound and restoration of its normal structure, while simultaneously inhibiting abnormal inflammation and fibrosis (the main cause of intrauterine adhesions). The PRP gel in this application contains platelet-rich plasma with a platelet concentration 3.0–4.0 times higher than the baseline whole blood concentration. Upon activation, it can release sufficient amounts of platelet-derived growth factor, transforming growth factor, and other bioactive growth factors. These growth factors can directly act on endometrial epithelial cells and stromal cells, promoting cell proliferation and differentiation, and accelerating the epithelialization process of the wound. Simultaneously, they can induce vascular endothelial cell migration and regeneration, improving local blood supply to the endometrium and providing sufficient nutrition for tissue repair, fundamentally solving the problem of slow postoperative endometrial repair.

[0069] The key cause of intrauterine adhesions is the tissue fibrosis and adhesion formation triggered by excessive postoperative inflammatory response. The PRP gel described in this application possesses the core advantage of "low leukocyte concentration and low pro-inflammatory risk": its leukocyte concentration is only 0.40–0.60 times the baseline whole blood concentration, significantly reducing the release of pro-inflammatory cytokines (such as interleukin-1β and tumor necrosis factor-α), thus preventing excessive activation of the inflammatory response; simultaneously, the erythrocyte concentration is controlled at 0.005–0.015 times the baseline whole blood concentration, and the extremely low erythrocyte residue can prevent oxidative stress and secondary inflammation caused by hemoglobin and iron ions after hemolysis, inhibiting the inflammation-mediated fibrosis process from its source. Furthermore, the fibrin network formed by thrombin activation in the PRP gel can act as a temporary physical barrier, covering the endometrial wound, reducing direct contact and adhesion between adjacent tissues within the uterine cavity, and creating a stable physical environment for endometrial repair.

[0070] Biocompatibility and safety are critical prerequisites for intrauterine medication. The PRP gel of this application removes harmful residues (such as unreacted monomers and solvents in the separating gel) through a precise separation process, and each component (acrylate resin, surface-modified nano-silica composite material, etc.) has excellent bioinertness after functional design, avoiding stimulation or immune response to sensitive tissues in the uterine cavity; the gel activation process (mixing platelet-rich plasma and thrombin at a volume ratio of 9:1) is gentle and controllable, and the resulting gel structure is stable and biodegradable, leaving no foreign matter in the uterine cavity, ensuring medication safety.

[0071] In summary, the PRP gel of this application promotes endometrial regeneration and repair through high concentrations of growth factors, inhibits fibrosis and adhesion-inducing factors with low pro-inflammatory properties, constructs a physical protective barrier through a fibrin network, and also has good biocompatibility and safety. It fully meets the clinical needs of post-hysteroscopic repair and prevention of intrauterine adhesions, and therefore can be used to prepare related drugs.

[0072] The core advantages of this application lie in the precise synergy of the preparation system, the targeted optimization of product performance, the high degree of adaptability to clinical applications, and the comprehensive guarantee of safety in use. These advantages support each other and form a complete technological closed loop.

[0073] At the preparation system level, this application constructs a functionally synergistic PRP separating gel system through ingenious molecular-level design. Each component has a clear division of labor and works closely together: acrylate resins provide a stable structural framework, surface-modified nano-silica composite materials achieve precise density control and bio-anti-adhesion function, and polyether-modified polysiloxanes and polyvinylpyrrolidone optimize interfacial properties and biocompatibility. The synergistic effect of each component makes the separation process efficient and controllable, and the precise separation of the target components can be achieved without complicated operations, demonstrating good preparation feasibility and reproducibility.

[0074] In terms of product performance, the PRP gel of this application achieves a precise balance of core performance, possessing both excellent bioactivity and low pro-inflammatory properties. Through multiple anti-adhesion designs and density gradient separation, the platelet-rich plasma component of the PRP gel exhibits optimized characteristics of "high platelet count, low white blood cell count, and extremely low red blood cell count," ensuring sufficient release of growth factors to support tissue repair while reducing pro-inflammatory factors at the source. This overcomes the limitation of traditional PRP products, which are prone to inflammatory risks, and achieves a balance between bioactivity and safety.

[0075] At the clinical application level, the PRP gel in this application possesses strong clinical specificity, precisely matching the core needs of post-hysteroscopic repair and prevention of intrauterine adhesions. Its released growth factors can efficiently promote endometrial regeneration, the fibrin network can form a temporary physical barrier to reduce tissue adhesions, and its low pro-inflammatory properties can inhibit excessive inflammation and fibrosis. This multi-mechanism synergistic effect directly addresses clinical pain points, providing a targeted solution for post-operative repair of sensitive areas, demonstrating significant clinical application value.

[0076] Regarding safety, this application ensures the biocompatibility of the product through rigorous preparation processes and component design. The components of the separating gel exhibit excellent bioinertness after functionalization modification. Harmful residues are thoroughly removed during the preparation process through purification steps. The structure formed after gel activation is stable and biodegradable, leaving no foreign matter in the body and causing no irritation or immune response to sensitive tissues in the uterine cavity, thus providing reliable safety assurance for clinical application.

[0077] The present application is further illustrated below with reference to specific embodiments. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to national standards / industry standards / the disclosure herein; if there are no corresponding national standards / industry standards / the disclosure herein, they are performed according to generally accepted international standards, conventional conditions, or conditions recommended by the manufacturer.

[0078] Example 1 This embodiment provides a method for preparing a PRP gel with low pro-inflammatory risk and anemic leukocytes, which includes the following steps: S1. Preparation of PRP separating gel Synthesis of acrylate resins: In a 1L four-necked flask equipped with a stirrer, thermometer, condenser, and constant-pressure dropping funnel, add 460g of butyl acrylate (CAS No. 141-32-2), 15g of methyl methacrylate (CAS No. 80-62-6), 10g of styrene (CAS No. 100-42-5), 3.75g of glycidyl methacrylate (CAS No. 106-91-2), and 100g of dimethylformamide in sequence. Purge with nitrogen for protection, start stirring, and heat to 70°C. ℃; 11.5g of azobisisobutyronitrile (2.5% of the mass of butyl acrylate, CAS No. 78-67-1) was dissolved in the remaining 150g of dimethylformamide to prepare an initiator solution. The solution was slowly added dropwise through a constant pressure dropping funnel over a period of 5 hours. After the addition was complete, the mixture was kept at 70℃ for 1.5 hours. After the reaction was completed, the temperature was raised to 160℃ and the mixture was distilled under reduced pressure at a vacuum of -0.098MPa for 3 hours to remove the solvent and unreacted monomers, yielding a transparent acrylate resin. The resin was then cooled and sealed for storage.

[0079] Preparation of hollow mesoporous silica nanospheres: 10 g of polystyrene template spheres (source: Nanomx Beike Nano, model PS-100~10000) with a particle size of 300 nm were dispersed in 500 mL of ethanol-water mixed solvent (volume ratio 4:1), and 5 mL of ammonia catalyst was added. The mixture was stirred at 30 °C for 30 min. 20 g of tetraethyl orthosilicate (mass ratio to polystyrene template spheres 2:1, CAS number 78-10-4) was slowly added dropwise at a uniform rate, and the reaction was continued at 30 °C for 8 h. The polystyrene@silica core-shell structured microspheres were obtained by centrifugation. The polystyrene template was removed by washing three times with tetrahydrofuran. The product was calcined at 550 °C for 3 h to obtain a density of 0.89 g / cm³. 3 Hollow mesoporous silica nanospheres.

[0080] Preparation of surface-modified nano-silica composite material: 10g of hollow mesoporous silica nanospheres were dispersed in 200mL of anhydrous ethanol, and 1.5g of silane coupling agent KH560 (mass ratio of 0.15:1 to hollow mesoporous silica nanospheres, γ-glycidoxypropyltrimethoxysilane, CAS No. 2530-83-8) was added. The mixture was refluxed at 70℃ for 5h. After centrifugation, the mixture was washed three times with ethanol and dried under vacuum at 80℃ to obtain epoxy-functionalized hollow mesoporous silica. 5g of epoxy-functionalized hollow mesoporous silica was dispersed in borate buffer solution at pH=8.5, and then... 1.0 g of amino-terminated polyethylene glycol (molecular weight 2000 Da, NH2-PEG-NH2, CAS No. 24991-53-5, sourced from Xi'an Qiyue Biotechnology) (mass ratio of 0.2:1 with epoxy-functionalized hollow mesoporous silica) and 0.75 g of sodium dextran sulfate (molecular weight 40000 Da, CAS No. 9011-18-1) (mass ratio of 0.15:1 with epoxy-functionalized hollow mesoporous silica) were reacted at 35 °C for 10 h. After centrifugation, the mixture was washed three times alternately with water and ethanol, and then vacuum dried at 60 °C to obtain a surface-modified nano-silica composite material.

[0081] Preparation of polyether-modified polysiloxane: Under nitrogen protection, 10 g of hydrogen-containing silicone oil (hydrogen content 0.8%, CAS No. 63148-57-2) and 18.5 g of allyl polyoxyethylene methyl-terminated polyether (molecular weight 2000 Da, CAS No. 27252-80-8) (molar ratio of Si-H bond in hydrogen-containing silicone oil to C=C bond in allyl polyoxyethylene methyl-terminated polyether 1:1.1) were dissolved in 50 mL of toluene. A solution of chloroplatinic acid in isopropanol (platinum content 75 ppm, based on the mass of hydrogen-containing silicone oil) was added, and the mixture was heated to 85 °C and reacted for 6 h. After the reaction was completed, the solvent and unreacted monomers were removed by vacuum distillation to obtain a pale yellow transparent polyether-modified polysiloxane.

[0082] Preparation of PRP separating gel: Take 100g of the above acrylate resin, add 9.0g of surface-modified nano-silica composite material, 1.0g of polyether-modified polysiloxane, and 0.75g of polyvinylpyrrolidone (K30, CAS No. 9003-39-8). Use a planetary disperser to disperse under a vacuum of -0.096MPa according to the following parameters: Step 1: stir for 15rpm and 15min; Step 2: stir for 35rpm and disperse for 250rpm and 70min; Step 3: stir for 15rpm and 15min; Step 4: stir for 35rpm and disperse for 150rpm and 70min to obtain a uniform PRP separating gel.

[0083] S2, Preparation of platelet-rich plasma 10 mL of peripheral blood was collected from a healthy volunteer using a vacuum blood collection tube containing the aforementioned PRP separating gel. The blood was centrifuged at 1800 g for 12 minutes to obtain platelet-rich plasma at the PRP separating gel interface. Blood cell analysis showed that the platelet concentration of this platelet-rich plasma was 3.6 × 10⁻⁶. 5 / μL (baseline whole blood concentration 1.0×10⁻⁶) 5 The white blood cell count was 3.2 × 10⁶ / μL (3.6 times that of normal cells). 3 / μL (baseline whole blood concentration 6.0×10⁻⁶) 3 The concentration of red blood cells was 0.04 × 10⁻⁶ μL (0.53 times that of μL). 6 / μL (baseline whole blood concentration 4.5×10⁻⁶) 6 (0.009 times the concentration of platelet-rich plasma per μL), as shown in the image below. Figure 2 As shown, the appearance of the product after centrifugation with PRP separating gel is presented intuitively. Combined with the test data, it can be seen that the plasma has good clarity and no obvious blood cell contamination, which confirms the high efficiency of platelet enrichment and the effective blocking of white blood cells and red blood cells by the separating gel.

[0084] S3. Preparation of PRP gel Take 4.5 mL of the above platelet-rich plasma, add 0.5 mL of thrombin solution (500 IU / mL, sourced from Hualan Biological), gently mix well, and let stand at 37°C. A uniform PRP gel will form within 10 seconds. The actual image of the PRP gel is shown below. Figure 3 As shown, the gel morphology formed after platelet-rich plasma and thrombin activation is clearly demonstrated. The gel texture is uniform, without layering or granularity, which meets the technical requirement of forming a uniform gel within 10 seconds.

[0085] Example 2 This embodiment provides a method for preparing a PRP gel with low pro-inflammatory risk and anemic leukocytes, which includes the following steps: S1. Preparation of PRP separating gel Synthesis of acrylate resins: In a 1L four-necked flask equipped with a stirrer, thermometer, condenser, and constant-pressure dropping funnel, 455g of butyl acrylate, 17.5g of methyl methacrylate, 7.5g of styrene, 2.5g of glycidyl methacrylate, and 100g of dimethylformamide were added sequentially. Nitrogen gas was introduced for protection, and the mixture was stirred and heated to 65°C. 9.1g of azobisisobutyronitrile (2.0% of the mass of butyl acrylate) was dissolved in the remaining 150g of dimethylformamide to prepare an initiator solution. This initiator solution was slowly added dropwise through the constant-pressure dropping funnel over a period of 4 hours. After the addition was complete, the mixture was kept at 65°C for 1 hour. After the reaction was completed, the mixture was heated to 155°C and distilled under reduced pressure at -0.097MPa for 2.5 hours to remove the solvent and unreacted monomers, yielding a transparent acrylate resin. The resin was cooled and then sealed for storage.

[0086] Preparation of hollow mesoporous silica nanospheres: 10 g of polystyrene template spheres with a particle size of 200 nm were dispersed in 500 mL of an ethanol-water mixed solvent (volume ratio 4:1), and 5 mL of ammonia catalyst was added. The mixture was stirred at 25 °C for 30 min. 15 g of tetraethyl orthosilicate (mass ratio to polystyrene template spheres 1.5:1) was slowly added dropwise at a uniform rate, and the reaction was continued at 25 °C for 6 h. The polystyrene@silica core-shell structured microspheres were obtained by centrifugation. The polystyrene template was removed by washing three times with tetrahydrofuran. The product was calcined at 500 °C for 2 h to obtain a density of 0.88 g / cm³. 3 Hollow mesoporous silica nanospheres.

[0087] Preparation of surface-modified nano-silica composite material: 10 g of hollow mesoporous silica nanospheres were dispersed in 200 mL of anhydrous ethanol, and 1.0 g of silane coupling agent KH560 (mass ratio of hollow mesoporous silica nanospheres to 0.1:1) was added. The mixture was refluxed at 60 °C for 4 h. After centrifugation, the nanospheres were washed three times with ethanol and dried under vacuum at 80 °C to obtain epoxy-functionalized hollow mesoporous silica. 5 g of epoxy-functionalized hollow mesoporous silica was dispersed in boron solution at pH 8.0. In an acid buffer solution, 0.5 g of amino-terminated polyethylene glycol (molecular weight 2000 Da) (mass ratio of 0.1:1 to epoxy-functionalized hollow mesoporous silica) and 0.25 g of sodium dextran sulfate (molecular weight 40000 Da) (mass ratio of 0.05:1 to epoxy-functionalized hollow mesoporous silica) were added sequentially, and the mixture was reacted at 25 °C for 8 h. After centrifugation, the mixture was washed three times alternately with water and ethanol, and then vacuum dried at 60 °C to obtain a surface-modified nano-silica composite material.

[0088] Preparation of polyether-modified polysiloxane: Under nitrogen protection, 10 g of hydrogen-containing silicone oil (0.8% hydrogen content) and 16.8 g of allyl polyoxyethylene methyl-terminated polyether (molecular weight 2000 Da) (the molar ratio of Si-H bonds in the hydrogen-containing silicone oil to C=C bonds in the allyl polyoxyethylene methyl-terminated polyether is 1:1.0) were dissolved in 50 mL of toluene, and a solution of isopropanol containing chloroplatinic acid (platinum content 50 ppm, based on the mass of the hydrogen-containing silicone oil) was added. The mixture was heated to 80 °C and reacted for 4 h. After the reaction was completed, the solvent and unreacted monomers were removed by vacuum distillation to obtain a pale yellow transparent polyether-modified polysiloxane.

[0089] Preparation of PRP separating gel: Take 100g of the above acrylate resin, add 10.0g of surface-modified nano silica composite material, 0.8g of polyether-modified polysiloxane, and 0.5g of polyvinylpyrrolidone (K30). Use a planetary disperser to disperse the gel under a vacuum of -0.095MPa according to the following parameters: Step 1: stir for 15rpm and 15min; Step 2: stir for 35rpm and disperse for 250rpm and 70min; Step 3: stir for 15rpm and 15min; Step 4: stir for 35rpm and disperse for 150rpm and 70min to obtain a uniform PRP separating gel.

[0090] S2, Preparation of platelet-rich plasma 10 mL of peripheral blood was collected from a healthy volunteer using a vacuum blood collection tube containing the aforementioned PRP separating gel. The blood was centrifuged at 1500 g for 10 min to obtain platelet-rich plasma (PRP) at the PRP separating gel interface. Blood cell analysis showed that the platelet concentration of this PRP PRP was 3.0 × 10⁻⁶. 5 / μL (baseline whole blood concentration 1.0×10⁻⁶) 5 (3.0 times that of μL), white blood cell concentration was 2.4 × 10⁹ / μL. 3 / μL (baseline whole blood concentration 6.0×10⁻⁶) 3 The concentration of red blood cells was 0.02 × 10⁻⁶ μL (0.40 times that of μL). 6 / μL (baseline whole blood concentration 4.5×10⁻⁶) 6 (0.005 times the concentration of μL).

[0091] S3. Preparation of PRP gel Take 4.5 mL of the above platelet-rich plasma, add 0.5 mL of thrombin solution (500 IU / mL), mix gently and let stand at 37°C. A uniform PRP gel will form within 10 seconds.

[0092] Example 3 This embodiment provides a method for preparing a PRP gel with low pro-inflammatory risk and anemic leukocytes, which includes the following steps: S1. Preparation of PRP separating gel Synthesis of acrylate resins: In a 1L four-necked flask equipped with a stirrer, thermometer, condenser, and constant-pressure dropping funnel, 465g of butyl acrylate, 12.5g of methyl methacrylate, 12.5g of styrene, 5.0g of glycidyl methacrylate, and 100g of dimethylformamide were added sequentially. Nitrogen gas was introduced for protection, and the mixture was stirred and heated to 75°C. 13.95g of azobisisobutyronitrile (3.0% of the mass of butyl acrylate) was dissolved in the remaining 150g of dimethylformamide to prepare an initiator solution. This initiator solution was slowly added dropwise through the constant-pressure dropping funnel over a period of 6 hours. After the addition was complete, the mixture was kept at 75°C for 2 hours. After the reaction was completed, the mixture was heated to 165°C and distilled under reduced pressure at a vacuum of -0.099MPa for 3.5 hours to remove the solvent and unreacted monomers, yielding a transparent acrylate resin. The resin was cooled and then sealed for storage.

[0093] Preparation of hollow mesoporous silica nanospheres: 10 g of polystyrene template spheres with a particle size of 400 nm were dispersed in 500 mL of an ethanol-water mixed solvent (volume ratio 4:1), and 5 mL of ammonia catalyst was added. The mixture was stirred at 35 °C for 30 min. 25 g of tetraethyl orthosilicate (mass ratio to polystyrene template spheres 2.5:1) was slowly added dropwise at a uniform rate, and the reaction was continued at 35 °C for 12 h. The polystyrene@silica core-shell structured microspheres were obtained by centrifugation. The polystyrene template was removed by washing three times with tetrahydrofuran. The product was calcined at 600 °C for 4 h to obtain a density of 0.90 g / cm³. 3 Hollow mesoporous silica nanospheres.

[0094] Preparation of surface-modified nano-silica composite material: 10 g of hollow mesoporous silica nanospheres were dispersed in 200 mL of anhydrous ethanol, and 2.0 g of silane coupling agent KH560 (mass ratio of hollow mesoporous silica nanospheres to 0.2:1) was added. The mixture was refluxed at 80 °C for 6 h. After centrifugation, the nanospheres were washed three times with ethanol and dried under vacuum at 80 °C to obtain epoxy-functionalized hollow mesoporous silica. 5 g of epoxy-functionalized hollow mesoporous silica was dispersed in boron solution at pH 9.0. In an acid buffer solution, 1.5 g of amino-terminated polyethylene glycol (molecular weight 2000 Da) (mass ratio of 0.3:1 to epoxy-functionalized hollow mesoporous silica) and 1.25 g of sodium dextran sulfate (molecular weight 40000 Da) (mass ratio of 0.25:1 to epoxy-functionalized hollow mesoporous silica) were added sequentially, and the mixture was reacted at 45 °C for 12 h. After centrifugation, the mixture was washed three times alternately with water and ethanol, and then vacuum dried at 60 °C to obtain a surface-modified nano-silica composite material.

[0095] Preparation of polyether-modified polysiloxane: Under nitrogen protection, 10 g of hydrogen-containing silicone oil (0.8% hydrogen content) and 20.2 g of allyl polyoxyethylene methyl-terminated polyether (molecular weight 2000 Da) (the molar ratio of Si-H bonds in the hydrogen-containing silicone oil to C=C bonds in the allyl polyoxyethylene methyl-terminated polyether is 1:1.2) were dissolved in 50 mL of toluene. A solution of chloroplatinic acid in isopropanol (platinum content 100 ppm, based on the mass of the hydrogen-containing silicone oil) was added, and the mixture was heated to 95 °C and reacted for 8 h. After the reaction was completed, the solvent and unreacted monomers were removed by vacuum distillation to obtain a pale yellow transparent polyether-modified polysiloxane.

[0096] Preparation of PRP separating gel: Take 100g of the above acrylate resin, add 10.0g of surface-modified nano silica composite material, 1.2g of polyether-modified polysiloxane, and 1.0g of polyvinylpyrrolidone (K30). Use a planetary disperser to disperse under a vacuum of -0.097MPa according to the following parameters: Step 1: stir for 15rpm and 15min; Step 2: stir for 35rpm and disperse for 250rpm and 70min; Step 3: stir for 15rpm and 15min; Step 4: stir for 35rpm and disperse for 150rpm and 70min to obtain a uniform PRP separating gel.

[0097] S2, Preparation of platelet-rich plasma 10 mL of peripheral blood was collected from a healthy volunteer using a vacuum blood collection tube containing the aforementioned PRP separating gel. The blood was centrifuged at 2000 g for 15 min to obtain platelet-rich plasma (PRP) at the PRP separating gel interface. Blood cell analysis showed that the platelet concentration of this PRP PRP was 4.0 × 10⁻⁶. 5 / μL (baseline whole blood concentration 1.0×10⁻⁶) 5 (4.0 times that of μL), white blood cell concentration was 3.6 × 10⁹ / μL. 3 / μL (baseline whole blood concentration 6.0×10⁻⁶) 3 The concentration of red blood cells was 0.07 × 10⁶ / μL (0.60 times that of the previous value). 6 / μL (baseline whole blood concentration 4.5×10⁻⁶) 6 (0.015 times the concentration of μL).

[0098] S3. Preparation of PRP gel Take 4.5 mL of the above platelet-rich plasma, add 0.5 mL of thrombin solution (500 IU / mL), mix gently and let stand at 37°C. A uniform PRP gel will form within 10 seconds.

[0099] Comparative Example 1 This comparative example is modified from the one disclosed in Example 1 as follows: In the synthesis of acrylate resins, glycidyl methacrylate was not added, and the monomer composition was adjusted to: 463.75g butyl acrylate, 15g methyl methacrylate, and 10g styrene. The remaining steps and parameters were exactly the same as in Example 1.

[0100] The platelet concentration of the platelet-rich plasma in this comparative study was 2.8 × 10⁻⁶. 5 / μL (baseline whole blood concentration 1.0×10⁻⁶) 5 The white blood cell count was 5.1 × 10⁹ / μL (2.8 times that of normal cells). 3 / μL (baseline whole blood concentration 6.0×10⁻⁶) 3 The concentration of red blood cells was 0.36 × 10⁻⁶ μL (0.85 times that of μL). 6 / μL (baseline whole blood concentration 4.5×10⁻⁶) 6 (0.08 times / μL).

[0101] Comparative Example 2 This comparative example is modified from the one disclosed in Example 1 as follows: The surface-modified hollow mesoporous silica nanospheres were replaced with an equal amount of ordinary solid hydrophilic nano-silica (density 2.2 g / cm³) without hollow structure design. 3 The solid silica also underwent the same surface modification with KH560 and PEG / dextran sulfate. The remaining steps and parameters were exactly the same as in Example 1.

[0102] The platelet concentration of the platelet-rich plasma in this comparative study was 5.2 × 10⁻⁶. 5 / μL (baseline whole blood concentration 1.0×10⁻⁶) 5 The white blood cell count was 5.7 × 10⁹ / μL (5.2 times that of normal cells). 3 / μL (baseline whole blood concentration 6.0×10⁻⁶) 3 The red blood cell concentration was 2.25 × 10⁹ / μL (0.95 times that of μL). 6 / μL (baseline whole blood concentration 4.5×10⁻⁶) 6 (0.50 times the concentration of μL).

[0103] Comparative Example 3 This comparative example is modified from the one disclosed in Example 1 as follows: In preparing the surface-modified nano-silica composite material, only the KH560 epoxy functionalization in step S121 was performed, and step S122 (i.e., no grafting of amino-PEG and sodium dextran sulfate) was omitted. The remaining steps and parameters were exactly the same as in Example 1.

[0104] The platelet concentration of the platelet-rich plasma in this comparative study was 3.2 × 10⁻⁶. 5 / μL (baseline whole blood concentration 1.0×10⁻⁶) 5 The white blood cell count was 5.7 × 10⁹ / μL (3.2 times that of normal cells). 3 / μL (baseline whole blood concentration 6.0×10⁻⁶) 3 The red blood cell concentration was 0.09 × 10⁹ / μL (0.95 times that of μL). 6 / μL (baseline whole blood concentration 4.5×10⁻⁶) 6 (0.020 times the concentration of μL).

[0105] Comparative Example 4 This comparative example is modified from the one disclosed in Example 1 as follows: No polyether-modified polysiloxane was added when preparing the PRP separating gel. The remaining steps and parameters were exactly the same as in Example 1.

[0106] The platelet concentration of the platelet-rich plasma in this comparative study was 2.5 × 10⁻⁶. 5 / μL (2.5 times the baseline whole blood concentration), white blood cell concentration was 4.8×10 3 / μL (0.80 times the baseline whole blood concentration), red blood cell concentration was 0.85×10 6 / μL (0.19 times the baseline concentration in whole blood).

[0107] Comparative Example 5 This comparative example is modified from the one disclosed in Example 1 as follows: Polyvinylpyrrolidone was not added when preparing the PRP separating gel. The remaining steps and parameters were exactly the same as in Example 1.

[0108] The platelet concentration of the platelet-rich plasma in this comparative study was 3.3 × 10⁻⁶. 5 / μL (baseline whole blood concentration 1.0×10⁻⁶) 5 The white blood cell count was 4.9 × 10⁹ / μL (3.3 times that of normal cells). 3 / μL (baseline whole blood concentration 6.0×10⁻⁶) 3 The red blood cell concentration was 0.08 × 10⁹ / μL (0.82 times that of μL). 6 / μL (baseline whole blood concentration 4.5×10⁻⁶) 6 (0.018 times the concentration of μL).

[0109] The components of platelet-rich plasma obtained in Examples 1-3 and Comparative Examples 1-5 are summarized in Table 1.

[0110] Table 1. Components of platelet-rich plasma in Examples 1-3 and Comparative Examples 1-5 As shown in Table 1, the platelet-rich plasma components of Examples 1-3 all strictly met the preset standards, exhibiting the core characteristics of "high platelet enrichment, low leukocyte residue, and extremely low erythrocyte residue." The platelet enrichment factor was stable at 3.00-4.00 times, ensuring sufficient release of growth factors in the subsequent gel; the leukocyte residue factor was controlled at 0.40-0.60 times, reducing the risk of pro-inflammatory reactions from the source; and the erythrocyte residue factor was only 0.005-0.015 times, avoiding hemolytic-related inflammatory triggers.

[0111] In Comparative Example 1, the absence of glycidyl methacrylate resulted in a 2.80-fold decrease in platelet enrichment, while the residual folds of white blood cells and red blood cells increased to 0.85-fold and 0.080-fold, respectively. The core reason is that the epoxy groups of glycidyl methacrylate are the key link between the surface-modified nano-silica composite material and polyvinylpyrrolidone. Their absence leads to nanoparticle aggregation, weak fixation of the bio-inert coating, and decreased density uniformity and anti-adhesion properties of the separating gel, making it ineffective in enriching platelets and failing to block white blood cells and red blood cells.

[0112] In Comparative Example 2, replacing hollow mesoporous silica with solid silica resulted in a 5.2-fold increase in platelet enrichment, while the residual leukocyte and erythrocyte counts surged to 0.95 and 0.50 times, respectively. The core reason for this is the fundamental density mismatch: solid silica has a density of 2.2 g / cm³. 3 The concentration of silica is far higher than that of hollow mesoporous silica (0.88~0.90 g / cm³). 3 This resulted in a significantly higher overall density of the PRP separating gel. During centrifugation, the separating gel failed to accurately adhere to the target density layer between plasma and blood cells, instead settling to a lower layer. The lower physical position of the density barrier led to increased platelet recovery and near-ineffective barrier effects against red and white blood cells, resulting in extensive contamination of the plasma layer by blood cells, with the highest density red blood cells exhibiting the most severe penetration. Furthermore, in some experimental batches, due to the excessively high density of the separating gel, it was observed that the gel failed to stably form an interface after centrifugation, instead settling to the bottom of the test tube, leading to separation failure and the inability to obtain an effective platelet-rich plasma layer.

[0113] Comparative Example 3, grafting amino-deficient end-capped polyethylene glycol with sodium dextran sulfate, showed a leukocyte retention factor of 0.95, the highest among all samples. Because the surface-modified nano-silica composite material lacked a dual anti-adhesion coating of "electrostatic-hydration," it could not actively repel leukocytes, resulting in a large amount of leukocytes adsorbing and remaining on the separation gel surface, thus failing to achieve the "leukocyte-poor" target.

[0114] In Comparative Example 4, the absence of polyether-modified polysiloxane resulted in a 2.5-fold decrease in platelet enrichment and an increase in leukocyte and erythrocyte residues to 0.80 and 0.19-fold, respectively. The fundamental reason for this is the loss of crucial thixotropic properties in the separating gel. Polyether-modified polysiloxane, through its polyether segments forming a dynamic hydrogen-bonded network with the system, imparts thixotropic properties to the separating gel, exhibiting "shear thinning and re-thickening upon standing." Without this component, the separating gel exhibits excessive fluidity under high shear during centrifugation, failing to rapidly rebuild a stable three-dimensional network structure after centrifugation ceases. This unstable, "liquid-like" state allows erythrocytes and leukocytes initially compressed beneath the separating gel to easily penetrate the gel barrier during centrifugal force changes or standing, diffusing back and contaminating the upper plasma layer. This leads to a significant increase in erythrocyte and leukocyte residues, while the unstable interface also affects the effective enrichment of platelets.

[0115] Comparative Example 5, lacking polyvinylpyrrolidone, showed a 0.82-fold increase in leukocyte retention and a 3.30-fold increase in platelet enrichment. Polyvinylpyrrolidone can form a hydrophilic brush-like coating on the separating gel surface, resisting plasma protein adsorption (a prerequisite for cell adhesion). Its absence increases protein adsorption, indirectly leading to leukocyte adhesion and retention. Simultaneously, the biocompatibility of the separating gel slightly decreases, affecting platelet enrichment efficiency.

[0116] The physicochemical properties of the PRP gels obtained in Examples 1-3 and Comparative Examples 1-5 were determined, and the results are shown in Table 2. The methods for determining the physicochemical properties are as follows: Gel time: Using the inverted test tube method, take the PRP gel mixture (platelet-rich plasma + thrombin) preheated at 37℃ and put it into a 10mL centrifuge tube. Place it in a 37℃ constant temperature incubator and record the time when the mixture stops flowing completely. Perform three parallel measurements and take the average value.

[0117] Gel strength: Using a texture analyzer (TA.XTPlus) with a P / 0.5R probe, a test speed of 1 mm / s, a compression distance of 2 mm, and a trigger force of 5 g, the stress value (kPa) when the gel is compressed to 20% deformation was measured. Five parallel measurements were taken and the average value was taken.

[0118] 24h swelling rate: The gel was made into a disc with a diameter of 8 mm and a thickness of 2 mm. The dry weight (W0) was accurately weighed and the gel was soaked in PBS buffer at 37℃ and pH=7.4. After 24 h, the gel was removed, the surface moisture was dried, and the wet weight (W1) was weighed. The swelling rate = (W1-W0) / W0×100%. The average value was taken from three parallel measurements.

[0119] 7-day in vitro degradation rate: The initial weight (W_initial) of the gel discs (as above) was accurately weighed and immersed in PBS buffer containing 0.1 mg / mL proteinase K. The discs were cultured at 37°C with shaking. After 7 days, the discs were removed, washed, freeze-dried, and the remaining weight (W_remaining) was weighed. The degradation rate was calculated as (W_initial - W_remaining) / W_initial × 100%. The average value was taken from three parallel determinations.

[0120] Table 2 Physicochemical properties of PRP gels from Examples 1-3 and Comparative Examples 1-5 As shown in Table 2, the PRP gels prepared in Examples 1-3 exhibit excellent and stable physicochemical properties, fully meeting the needs of clinical applications. Their gelation time is concentrated in the range of 8-10 seconds, satisfying the time window requirements of clinical operations while rapidly forming a structurally stable gel. The gel strength is 10.82-13.78 kPa, maintaining its shape within the uterine cavity and preventing rapid collapse after perfusion. The 24-hour swelling rate is controlled at 180.25-195.67%, ensuring sufficient absorption of tissue fluid for nutrient exchange without causing an increase in intrauterine pressure due to excessive swelling. The 7-day in vitro degradation rate is 75.82-82.36%, matching the endometrial repair cycle, allowing for gradual degradation after the repair function is completed, with no risk of foreign body residue. Furthermore, the standard deviation of each indicator is small, demonstrating good process repeatability.

[0121] Comparative Example 1 lacks glycidyl methacrylate. The epoxy group of this monomer is the key link connecting the surface-modified nano silica composite material and polyvinylpyrrolidone. Its absence leads to insufficient cross-linking of the system and a loose gel network structure. Therefore, it has the longest gel time (15.60±1.25s), the lowest gel strength (6.42±1.25kPa), the highest swelling rate at 24h (250.35±15.28%), and the fastest in vitro degradation rate at 7d (92.45±5.36%).

[0122] In Comparative Example 2, solid silica was used instead of hollow mesoporous silica nanospheres. Due to the density mismatch, the separating gel could not form a sharp and stable interface during centrifugation. As a result, too many red blood cells remained in the platelet-rich plasma, which affected the uniformity of the gel network, resulting in lower gel strength (7.63±0.98 kPa) and higher swelling and degradation rates.

[0123] Comparative Example 3, which involved grafting amino-deficient end-capped polyethylene glycol with sodium dextran sulfate, showed high levels of residual leukocytes. The enzymes released by these cells disrupted the gel network structure, causing the gel strength (9.25±0.86 kPa), swelling rate, and degradation rate to deviate from the optimal range.

[0124] Comparative Example 4: Polyether-modified polysiloxane was missing. This component can reduce the surface tension of the system and optimize the interface smoothness. However, after its absence, the mixing during gel formation was uneven and the network structure was defective, which was manifested as prolonged gelation time (12.78±0.72s), decreased strength (8.47±0.94kPa), and increased swelling rate and degradation rate.

[0125] Comparative Example 5 lacks polyvinylpyrrolidone, a component that can form a hydrophilic coating on the surface of the separating gel, improving biocompatibility. However, the lack of this component leads to an imbalance in the interaction between the gel and the biological environment, resulting in a slightly lower gel strength (10.25±0.88kPa) than in the Example, higher swelling and degradation rates, and decreased overall performance stability.

[0126] The application performance of the PRP gels obtained in Examples 1-3 and Comparative Examples 1-5 was determined, and the results are shown in Table 3. The application performance determination method is as follows: Concentrations of pro-inflammatory cytokines (IL-1β, TNF-α): PRP gel was incubated at 37°C for 24 h, the supernatant was collected, and the concentrations of IL-1β and TNF-α were measured using an enzyme-linked immunosorbent assay (ELISA) kit (purchased from R&D Systems) according to the instructions. The average value was taken from three parallel measurements.

[0127] Endometrial epithelial cell proliferation rate (48h): Human endometrial epithelial cells (hEECs) were seeded into 96-well plates (5×10³ cells / well). After culturing for 24h, PRP gel supernatant (20% V / mL) was added, and the cells were cultured for another 48h. The absorbance (OD450nm) was measured using a CCK-8 assay kit (purchased from DOJINDO). Cell proliferation rate = (OD value of experimental group - OD value of blank group) / (OD value of control group - OD value of blank group) × 100%. The control group was culture medium containing 20% ​​fetal bovine serum. The measurements were performed in 6 parallel trials and the average value was taken.

[0128] Inhibition rate of intrauterine adhesions in rats: A rat model of intrauterine adhesions was established. PRP gel (0.2 mL / rat) was instilled into the uterine cavity 7 days after surgery. The rats were sacrificed 21 days after surgery, and uterine tissue was collected for HE staining and Masson staining to observe the degree of intrauterine adhesions. The adhesion area was scored (0-4 points). The adhesion inhibition rate was calculated as (average adhesion score of model group - average adhesion score of experimental group) / average adhesion score of model group × 100%. Ten rats were in each group, and the average value was calculated.

[0129] Table 3. Application performance of PRP gels obtained in Examples 1-3 and Comparative Examples 1-5 As shown in Table 3, the PRP gels prepared in Examples 1-3 exhibited excellent and stable application performance, fully meeting the clinical needs for post-hysteroscopic repair and prevention of intrauterine adhesions. The concentrations of pro-inflammatory cytokines were significantly low, with IL-1β ranging from 85.45 to 92.36 pg / mL and TNF-α from 125.45 to 135.82 pg / mL. This result directly stems from the core design of the "leukopenia" principle in the implementation plan, where the residual leukocyte count was controlled at 0.40 to 0.60 times, reducing the source of pro-inflammatory cytokine release and fundamentally lowering the risk of postoperative inflammatory response. Simultaneously, the proliferation rate of endometrial epithelial cells reached 128.36 to 135.45%, with high proliferative activity attributed to platelet concentrations of 3.00 to 4.00 times the baseline in platelet-rich plasma. The sufficient amount of growth factors released (such as platelet-derived growth factor and transforming growth factor) effectively promoted endometrial cell regeneration. Furthermore, the inhibition rate of intrauterine adhesions in rats was 58.74 to 62.35%, demonstrating a synergistic effect of "low pro-inflammatory + high repair." This mechanism reduces fibrotic adhesions by inhibiting excessive inflammation and fills the wound by promoting endometrial regeneration, forming a dual anti-adhesion mechanism. The small standard deviation of each application performance index in the examples further confirms the stability and repeatability of the process, ensuring the consistency of clinical application effects.

[0130] Comparative Example 1, due to the lack of glycidyl methacrylate, resulted in insufficient platelet enrichment (2.80 times the baseline) and increased erythrocyte residue (0.080 times the baseline). On the one hand, the supply of growth factors was insufficient, and on the other hand, hemolytic products triggered additional inflammation, resulting in increased concentration of pro-inflammatory factors, decreased cell proliferation rate, and adhesion inhibition rate of only 38.45%.

[0131] Comparative Example 2 uses solid silica instead of hollow mesoporous silica nanospheres. The density mismatch resulted in a platelet enrichment factor of only 2.10 times and a red blood cell residue factor of 0.30 times. The synergistic effect of insufficient growth factors and hemolysis-induced inflammation caused the cell proliferation rate to be less than 100% and the adhesion inhibition rate to be only 35.62%.

[0132] Comparative Example 3 showed the worst performance, with the highest concentrations of IL-1β (185.63 pg / mL) and TNF-α (245.82 pg / mL), and the lowest rates of endometrial epithelial cell proliferation (95.25%) and intrauterine adhesion inhibition in rats (32.47%). This is because the comparative example lacked the grafting modification of amino-terminated polyethylene glycol and sodium dextran sulfate, and the surface-modified nano-silica composite material lost its dual anti-adhesion function of "electrostatic-hydration", resulting in a leukocyte residual multiple as high as 0.95 times. The pro-inflammatory factors released by a large number of leukocytes not only directly increased the inflammation level, but also inhibited endometrial cell proliferation, ultimately aggravating intrauterine adhesion.

[0133] Comparative Example 4, which lacks polyether-modified polysiloxane, resulted in an uneven separation gel interface, leading to increased erythrocyte residue and decreased gel mixing uniformity. This affected the release of growth factors and the regulation of inflammation, manifested as a higher concentration of pro-inflammatory factors and a lower adhesion inhibition rate (42.25%) compared to the Example.

[0134] In Comparative Example 5, the absence of polyvinylpyrrolidone resulted in decreased bioinertness of the separating gel surface, increased leukocyte adhesion and retention (0.82 times baseline), and elevated concentrations of pro-inflammatory factors (IL-1β 125.47 pg / mL, TNF-α 185.62 pg / mL). The cell proliferation rate (115.82%) and adhesion inhibition rate (45.82%) were significantly lower than those in the Example, confirming the key role of this component in optimizing biocompatibility and reducing inflammatory triggers.

[0135] Clinical application data of the PRP gel in Example 1 were determined, and the results are shown in Table 4. The timing and method of PRP instillation were as follows: the first PRP intrauterine instillation was performed 2-3 days after menstruation ended, followed by two instillations per week. Typically, one course of treatment involves 3-5 instillations.

[0136] Meanwhile, this application provides an integrated PRP preparation and perfusion kit adapted for reproductive applications, which includes a PRP collection and separation tube, a PRP gel spray gun, and matching PRP preparation kit components, a dedicated perfusion catheter, and a mixing device.

[0137] The PRP collection and separation tube is the core separation component of the kit, used to collect peripheral whole blood from patients. Its built-in PRP separation gel is specially formulated for reproductive applications, achieving precise enrichment of target components through a proprietary formula. This ensures that a suitable PRP composition for reproductive applications is obtained after separation, providing high-quality bioactive raw materials for subsequent reproductive-related repair needs.

[0138] like Figure 4 As shown, the PRP gel spray gun adopts an AB tube structure design. Tube A is used to load the PRP composition purified by the PRP collection and separation tube, and tube B is used to load thrombin (activator). The two are matched at a volume ratio of 9:1, which is precisely matched with the activation requirements of PRP gel. The mixing end of tubes A and B is equipped with a dedicated mixer. When the solutions in the two tubes are mixed, a vortex effect is generated to ensure that the PRP composition and thrombin are quickly, uniformly and thoroughly mixed, ensuring the stability and consistency of the gel activation effect.

[0139] The PRP preparation kit provides basic support for blood collection and separation, including vacuum blood collection tubes with built-in PRP separation gel, blood collection needles, syringes, and injection needles. The components work together to achieve safe collection of peripheral whole blood and efficient separation of PRP, meeting the standardized requirements of clinical operations.

[0140] The catheter and mixing device required for perfusion consists of components such as a push handle, handle, administration device, three-way connector, adapter, spray head, conical spray, and flat-head needle. It is specifically adapted to perfusion operations in reproductive application scenarios. The components can be flexibly combined to ensure that the activated PRP gel can be applied accurately and conveniently to the target site, providing adaptive support for reproductive-related repair operations.

[0141] Table 4. Clinical application data of PRP gel in Example 1 As shown in Table 4, the clinical data fully validated the practical value of the PRP gel in the fields of intrauterine repair and assisted reproduction. Its therapeutic effects were highly consistent with the previous results of physicochemical and application performance tests. In terms of core efficacy, 449 patients received PRP intrauterine instillation, achieving a high implantation success rate of 95% and an overall pregnancy rate of 55%, demonstrating the gel's good clinical applicability and safety. No significant contraindications for implantation were caused by the material characteristics, consistent with previous results showing the gel's low concentration of pro-inflammatory factors and high biocompatibility.

[0142] In the subgroups, the 52% pregnancy rate in patients with intrauterine adhesions (IUA) significantly demonstrates the targeted repair advantage of the PRP gel in this application. Previous experiments have confirmed that the gel can effectively promote endometrial epithelial cell proliferation and inhibit intrauterine adhesions. Clinically, the 63% pregnancy rate in patients with Em>9mm is much higher than the 40% in patients with Em≤9mm, confirming the mechanism of action of the gel in improving pregnancy outcomes by promoting endometrial thickening. Even with worse baseline conditions, the pregnancy rate in the PRP group is still better than that in the non-perfusion group, accompanied by lower miscarriage and ectopic pregnancy rates, further highlighting the unique role of the gel in inhibiting fibrosis and optimizing the intrauterine microenvironment. The 58% pregnancy rate in patients with chronic endometritis (CE) echoes the anti-inflammatory properties of the gel. Previous data show that the gel can significantly reduce the concentration of pro-inflammatory factors such as IL-1β and TNF-α. Clinically, even with worse baseline conditions, it still achieves a pregnancy rate comparable to the non-perfusion group, verifying its actual effect in regulating the intrauterine immune microenvironment.

[0143] Data analysis of treatment timing and infusion location provided clear guidance for optimizing clinical application protocols: the pregnancy rate of infusion 2 days after hysteroscopy reached 71% (although the sample size was limited), and the pregnancy rate gradually decreased with the extension of the postoperative interval, suggesting that the intrauterine wound is more susceptible to the regulation of growth factors in PRP gel in the early postoperative period, which matches the degradation cycle and proliferation-promoting effect of the gel within 7-14 days in the early stage; and an interval of more than 3 days should be reserved after PRP infusion before transplantation (pregnancy rate of 56% in 3-8 days and 58.5% in ≥9 days), avoiding the problem of the gel not fully exerting its repair effect or the local microenvironment being unstable in a short period of time. In terms of infusion location, the pregnancy rate was significantly improved when it was ≥1cm from the fundus or >0.1 from the fundus / uterine depth (73.1% and 87.5%, respectively), which is consistent with the application performance requirements of the gel needing to evenly cover the intrauterine wound and fully contact the endometrial tissue in the early stage, optimizing the interaction efficiency between the gel and the endometrium and maximizing its effects of promoting repair and inhibiting adhesions. In summary, the clinical data not only confirms the clinical efficacy of the PRP gel in this application, but also clarifies its optimal application scenarios and operating procedures, providing a solid basis for its promotion and application.

[0144] The repair effect of the PRP gel in Example 1 of this application on patients with intrauterine adhesions has been more intuitively demonstrated in specific clinical cases, especially for patients with thin endometrium who do not respond well to conventional treatment, the advantages of PRP intrauterine infusion are more prominent.

[0145] Case 1: Patient Wang, 43 years old, presented with thin endometrium due to intrauterine adhesions during an IVF cycle. She had irregular menstruation with scanty flow, a history of four vaginal deliveries, one miscarriage with curettage, and four induced abortions (last in May 2021). On April 25, 2023, she underwent hysteroscopic adhesiolysis. Postoperatively, she received estradiol valerate, femoston, growth hormone (GH), and magnetic therapy to repair the endometrium. Gynecological ultrasound showed an endometrial thickness (En) of 5.4 mm, appearing as a hidden triple line. After three intrauterine injections of hyaluronic acid, the endometrial thickness only increased to 5.7 mm, still appearing as a hidden triple line. Therefore, in addition to the basic treatment (GH2 IU qd + low molecular weight heparin + estradiol + femoston), PRP intrauterine instillation therapy was added: the first PRP + PPP intrauterine injection was performed on day 8 of menstruation. A follow-up ultrasound 7 days later showed an endometrial enlargement (En) of 5mm (strong echo), endometrial blood flow RI 0.5, PI 0.8, S / D 2.0, and stable antral follicle count in both ovaries. A second PRP + PPP intrauterine injection was performed 7 days later. A follow-up ultrasound 7 days later showed an endometrial enlargement of 7mm (strong echo), improved endometrial blood flow to type II, stable blood flow parameters, and an increase in the number of antral follicles in the right ovary to 3. The PRP gel provided in Example 1 is shown in the intraoperative image of clinical case 1. Figure 5 As shown.

[0146] Case 2: Patient Yao, 37 years old, presented with a 13-year history of PCOS and a 10-year history of infertility. She had achieved complete remission after fertility-preserving treatment for stage IA1 (T1aN0M0) well-differentiated endometrioid adenocarcinoma, but her endometrium was too thin after hysteroscopic adhesiolysis for moderate to severe intrauterine adhesions. Reproductive history: G1P0. In March 2024, she underwent a hysteroscopic removal of pregnancy tissue at 7+2 weeks of gestation due to embryonic arrest. In October and November 2024, she was scheduled for another embryo transfer, but the endometrial thickness was less than 7mm on the day of HCG administration, resulting in the cancellation of one transfer. The embryo failed to implant after the first transfer. Gynecological ultrasound showed an endometrial thickness (En) of 1.1-3.4 mm, uneven endometrial thickness, and polycystic changes in both ovaries. PRP plus terzine intrauterine instillation was performed seven times (without estrogen therapy). A follow-up ultrasound showed an En thickness increased to 7.0 mm, with an heterogeneous endometrium and small cystic hypoechoic areas, a hypoechoic area on the posterior uterine wall (partially communicating with the uterine cavity), and the ovaries still showing polycystic changes. Endometrial blood flow was type I (RI 0.63, PI 0.94, S / D = 2.71). Uterine artery (left) RI 0.89, PI 3.20, S / D = 9.23, (right) RI 0.89, PI 2.77, S / D = 8.41. Hysteroscopy and endometrial biopsy were subsequently performed. Intraoperative images of the PRP gel provided in Example 1 of this application in clinical case 2 are shown below. Figure 6 As shown.

[0147] As can be seen from Cases 1 and 2, the PRP gel of this application, when used for intrauterine irrigation, has a clear repair effect on endometrial thinning caused by various complex intrauterine procedures (intrauterine adhesion separation, intrauterine repair after tumor-preserving fertility treatment). In Case 1, after hysteroscopic adhesiolysis, conventional hormone therapy combined with hyaluronic acid injection only increased the endometrial thickness from 5.4 mm to 5.7 mm, showing limited thickening effect. However, after two additional PRP infusions, the endometrial thickness increased from 5.7 mm to 7 mm, and the endometrial blood flow improved from unclassified to type II, verifying the dual effect of PRP in promoting endometrial proliferation and optimizing local blood supply. In Case 2, the patient had a history of PCOS, fertility-preserving treatment for endometrial cancer, and multiple embryo transfer-related intrauterine procedures. The endometrium repeatedly thinned and was not treated with estrogen. After seven PRP infusions combined with terzine, the endometrial thickness successfully increased from 1.1-3.4 mm to 7.0 mm, demonstrating the effectiveness and wide applicability of PRP in repairing complex endometrial injuries. Furthermore, during and after PRP infusion in both patients, ovarian function-related indicators (antral follicle count and ovarian morphology) were not adversely affected, further confirming the safety of PRP intrauterine infusion. Its core mechanism of releasing high concentrations of growth factors to mediate endometrial repair can effectively solve the problem of refractory thin endometrium that is not well treated with conventional methods in clinical practice, creating favorable intrauterine conditions for embryo transfer.

[0148] The range descriptions used herein, such as numerical ranges and proportional ranges, include all possible sub-ranges and single values ​​within that range. For example, the range descriptions "1 to 6" or "1 to 6" cover all sub-ranges (such as 1 to 3, 2 to 5, etc.) and single numbers (such as 1, 2, 3, 4, 5, 6) between 1 and 6. Unless otherwise specified, the terms "including" or "comprises" as used herein mean "including but not limited to". Proportional relationships mentioned herein, such as mass ratios and molar ratios, should be understood as a correspondence between the first and second terms of a proportional formula, in the order of their description. All raw materials, reagents, instruments, and equipment used herein can be obtained commercially or prepared using existing methods.

[0149] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. This application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for preparing a PRP gel with low pro-inflammatory risk and low leukocyte count, characterized in that, The method includes the following steps: S1. Under high vacuum conditions, acrylate resin and surface-modified nano-silica composite material are dispersed and mixed in multiple steps, then polyether-modified polysiloxane and polyvinylpyrrolidone are added and dispersed and mixed in multiple steps to obtain PRP separating adhesive. S2. Peripheral blood is collected using a vacuum blood collection tube containing the PRP separating gel. After centrifugation, platelet-rich plasma is obtained on the interface of the PRP separating gel. S3. The platelet-rich plasma is mixed with an initiator and activated to obtain PRP gel; The mass ratio of the acrylate resin, the surface-modified nano-silica composite material, the polyether-modified polysiloxane, and the polyvinylpyrrolidone is 100:(8-10):(0.8-1.2):(0.5-1.0). The acrylate resin is polymerized from the following monomers in parts by weight: 91-93 parts butyl acrylate, 2.5-3.5 parts methyl methacrylate, 1.5-2.5 parts styrene, and 0.5-1.0 parts glycidyl methacrylate. The platelet-rich plasma has the following components: platelet concentration is 3.0 to 4.0 times the baseline whole blood concentration, white blood cell concentration is 0.40 to 0.60 times the baseline whole blood concentration, and red blood cell concentration is 0.005 to 0.015 times the baseline whole blood concentration.

2. The method for preparing PRP gel according to claim 1, characterized in that, The preparation method of the acrylate resin includes the following steps: S111. The butyl acrylate, the methyl methacrylate, the styrene, and the glycidyl methacrylate are added to dimethylformamide to obtain a monomer mixture; S112. Dissolve azobisisobutyronitrile in dimethylformamide to obtain an initiator solution; S113. Heat the monomer mixture to 65-75°C, then add the initiator solution dropwise, controlling the dropwise addition time to be 4-6 hours. After the dropwise addition is completed, keep it at 65-75°C for 1-2 hours to obtain the reaction solution. S114. The reaction solution is subjected to heated and vacuum distillation to remove the solvent and unreacted monomers, thereby obtaining the acrylate resin.

3. The method for preparing PRP gel according to claim 2, characterized in that, The mass of the azobisisobutyronitrile is 2.0 to 3.0% of the mass of the butyl acrylate.

4. The method for preparing PRP gel according to claim 1, characterized in that, The preparation method of the surface-modified nano-silica composite material includes the following steps: S121. Hollow mesoporous silica nanospheres were dispersed in anhydrous ethanol, a silane coupling agent was added, and the mixture was refluxed at 60-80°C for 4-6 hours. After the reaction was completed, the nanospheres were separated, washed, and dried to obtain epoxy-functionalized hollow mesoporous silica. S122. The epoxy-functionalized hollow mesoporous silica is dispersed in an alkaline buffer solution, and then amino-terminated polyethylene glycol and sodium dextran sulfate are added sequentially. The reaction is carried out at 25-45°C for 8-12 hours. After the reaction is completed, the solid product is separated, washed, and dried to obtain the surface-modified nano silica composite material.

5. The method for preparing PRP gel according to claim 4, characterized in that, The density of the hollow mesoporous silica nanospheres is 0.88~0.90 g / cm³. 3 ; The mass ratio of the silane coupling agent to the hollow mesoporous silica nanospheres is (0.1-0.2):1; The mass ratio of the epoxy-functionalized hollow mesoporous silica, the amino-terminated polyethylene glycol, and the sodium dextran sulfate is 1:(0.1-0.3):(0.05-0.25).

6. The method for preparing PRP gel according to claim 5, characterized in that, The method for preparing the hollow mesoporous silica nanospheres includes the following steps: S121a. Polystyrene template spheres are dispersed in an alcohol-water mixed solvent, then ammonia catalyst is added, and after stirring evenly, tetraethyl orthosilicate is slowly added dropwise. The silicon source hydrolysis reaction is carried out at 25-35℃ for 6-12 hours. S121b After the reaction is complete, centrifugation is performed to obtain polystyrene@silica core-shell structured microspheres. The polystyrene template is removed by washing with an organic solvent to obtain the intermediate product. S121c. The intermediate product is calcined at 500-600°C for 2-4 hours to obtain hollow mesoporous silica nanospheres. The polystyrene template spheres have a particle size of 200–400 nm. The mass ratio of the tetraethyl orthosilicate to the polystyrene template sphere is (1.5-2.5):

1.

7. The method for preparing PRP gel according to claim 1, characterized in that, The preparation method of the polyether-modified polysiloxane includes the following steps: S131. Dissolve hydrogen-containing silicone oil, allyl polyoxyethylene methyl-terminated polyether and chloroplatinic acid in isopropanol solution in organic solvent, stir evenly under inert gas protection to obtain reaction solution; S132. Heat the reaction solution to 80-95°C and react for 4-8 hours; S133. After the reaction is complete, the reaction system is subjected to vacuum distillation to remove the organic solvent and unreacted monomers, thereby obtaining the polyether-modified polysiloxane. The molar ratio of Si-H bonds in the hydrogen-containing silicone oil to C=C bonds in the allyl polyoxyethylene methyl-terminated polyether is 1:(1.0-1.2). The mass of the chloroplatinic acid is 0.005% to 0.010% of the mass of the hydrogen-containing silicone oil.

8. The method for preparing PRP gel according to claim 1, characterized in that, The initiator is thrombin, and the volume ratio of the platelet-rich plasma to the initiator is 9:1; The centrifugal force is 1500-2000g, and the centrifugation time is 10-15min.

9. A PRP gel prepared by the method according to any one of claims 1 to 8, characterized in that, The PRP gel is made by activating platelet-rich plasma and thrombin in a volume ratio of 9:

1.

10. The use of the PRP gel of claim 9 in the preparation of a medicament for post-hysteroscopic repair and prevention of intrauterine adhesions.

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