Composite biological material for rapid hemostasis and bone regeneration after tooth extraction and preparation method thereof

Abstract

The invention relates to a composite biological material for rapid hemostasis and bone regeneration after tooth extraction and a preparation method thereof. The composite biological material for rapid hemostasis and bone regeneration after tooth extraction is prepared from the following raw materials: dialdehyde starch, chitosan-catechol, gelatin and a response material PEG-SS loaded with PRP. The dialdehyde starch, the chitosan-catechol and the gelatin have a synergistic effect, so that physical compression hemostasis can be quickly realized, and meanwhile, a response material PEG-SS loaded with PRP is added, so that slow release of growth factors can be realized, the hemostasis effect can be prolonged, and bone regeneration can be supported. The preparation method is further combined for optimization to prepare powder, and the powder can be directly filled for use, is good in swelling effect and quick in hemostasis, and can provide long-acting hemostasis and healing support.

Description

Technical Field

[0001] The present invention relates to the field of biomaterials, in particular to a composite biomaterial for rapid hemostasis and bone regeneration after tooth extraction and a preparation method thereof. Background Art

[0002] Hemostasis and bone regeneration after tooth extraction are particularly important in dentistry. Tooth extraction can expose and damage the alveolar bone, making postoperative bleeding, infection, and poor bone healing more likely. This is especially true for patients planning subsequent dental implants, as the health of the alveolar bone directly impacts the stability and long-term function of the implant. However, traditional hemostatic methods, such as physical compression and topical application of hemostatic drugs, typically only provide short-term hemostasis and are unable to effectively promote bone regeneration in the extraction wound.

[0003] The main products for post-extraction hemostasis and bone regeneration on the market include:

[0004] 1. Fibrin sponge: Fibrin sponge is a medical hemostatic material with excellent biocompatibility and water-swelling properties. It rapidly stops bleeding by binding to coagulation factors in the blood. However, fibrin sponge primarily provides a physical hemostatic effect and cannot promote bone regeneration.

[0005] 2. Gelatin sponge: Gelatin sponge expands to form a gel after absorbing water. It can physically compress wounds to achieve short-term hemostasis and is gradually absorbed into the body. However, its main limitation is that it can only physically stop bleeding and cannot support long-term bone regeneration.

[0006] 3. Topical application of PRP: PRP is obtained from the patient's own blood through centrifugation and is rich in growth factors (such as PDGF, TGF-β, VEGF, etc.), which has the potential to promote angiogenesis and bone regeneration. However, liquid PRP is difficult to retain in the wound for a long time and is easily lost with blood or saliva. Furthermore, the rate of growth factor release is difficult to control, making it difficult to achieve long-term bone regeneration support.

[0007] However, these existing products have short hemostatic effects. For example, some materials lack structural stability, are prone to softening or disintegrating after absorbing water and swelling, have poor mechanical strength, and cannot provide stable hemostatic support in the dynamic environment of the oral cavity for a long time. It can only provide a short-term hemostatic effect, but in complex tooth extraction operations, the hemostatic effect is not long-lasting and can easily cause secondary bleeding. Moreover, these traditional hemostatic materials tend to be hemostatic and do not provide good support for alveolar bone regeneration, especially when there is bone absorption or poor healing of the tooth extraction wound, the stability of subsequent implants may be affected. Although PRP is rich in growth factors, the release of its growth factors is not controlled, resulting in its action time not being long enough, which also affects the bone regeneration effect. Summary of the Invention

[0008] To address the shortcomings of existing technologies, the present invention proposes a composite biomaterial based on dialdehyde starch (CMS), chitosan, gelatin, PRP, and the intelligent responsive material PEG-SS. This composite material can effectively achieve rapid hemostasis after tooth extraction and promote bone tissue regeneration, with long-lasting and stable effects.

[0009] To achieve the above object, the present invention provides the following technical solutions:

[0010] The first aspect of the present invention provides a composite biomaterial for rapid hemostasis and bone regeneration after tooth extraction, the raw materials of which include: dialdehyde starch, chitosan-catechol, gelatin, and a responsive material PEG-SS loaded with PRP.

[0011] Dialdehyde starch, chitosan-catechol, and gelatin work synergistically to achieve physical compression and hemostasis. The addition of PEG-SS (polyethylene glycol-disulfide bond), a responsive material loaded with PRP, allows for the slow release of growth factors and sustained support for bone regeneration. This composite material provides long-term hemostasis and supports bone regeneration. It can be formulated into common hemostatic forms such as gels, sponges, and powders.

[0012] In some other embodiments, the PRP-loaded responsive material PEG-SS is obtained by dispersing PRP and the responsive material PEG-SS in a solvent, stirring the mixture, centrifuging, and freeze-drying. Preferably, the mass ratio of PRP to the responsive material PEG-SS is 1:4-5.

[0013] The composite bone regeneration material of the present invention can be a gel prepared from the above-mentioned materials, or a freeze-dried sponge product. Preferably, the composite biomaterial of the present invention is a powder prepared by freeze-drying the gel prepared from the above-mentioned raw materials. When used, it can be directly filled into the tooth extraction socket to swell and achieve a hemostatic effect, and is easy to produce, transport, and store.

[0014] Preferably, the gel comprises, by mass volume concentration, 1-4% dialdehyde starch, 0.5-1.25% chitosan-catechol, 2.5-5% gelatin, and 2.5-5% PEG-SS, a responsive material loaded with PRP. Further preferably, the gel comprises, by mass volume concentration, 1.25-4% dialdehyde starch, 0.8-1.25% chitosan-catechol, 3.5-5% gelatin, and 4-5% PEG-SS, a responsive material loaded with PRP.

[0015] Preferably, the composite biomaterial has a particle size of 100-200 microns and a fast swelling speed, so as to facilitate better use and filling.

[0016] The present invention also provides a method for preparing the composite biomaterial, comprising the steps of:

[0017] The gelatin solution, chitosan-catechol solution and dialdehyde starch solution were mixed, and the mixture was dropped into the responsive material PEG-SS loaded with PRP, stirred evenly, and then allowed to stand to obtain the gel.

[0018] Preferably, the gelatin solution, chitosan-catechol solution and dialdehyde starch solution are prepared by dissolving gelatin, chitosan-catechol and dialdehyde starch in pure water or PBS buffer, respectively.

[0019] Preferably, the concentration of the dialdehyde starch solution is 0.02-0.08 g / mL; the concentration of the chitosan-catechol solution is 0.02-0.05 g / mL; and the concentration of the gelatin solution is 0.1-0.2 g / mL.

[0020] Preferably, the volume ratio of gelatin solution: chitosan-catechol solution: dialdehyde starch solution is 1:1:2.

[0021] Compared with the prior art, the present invention has the following beneficial and unique effects:

[0022] The composite biomaterial for rapid hemostasis and bone regeneration after tooth extraction of the present invention comprises dialdehyde starch, chitosan-catechol, and gelatin, which work synergistically to absorb water and swell to form a gel, rapidly achieving physical compression hemostasis. Simultaneously, the addition of a PRP-loaded responsive material, PEG-SS, enables the slow release of growth factors, prolonging the hemostatic effect and supporting bone regeneration. Furthermore, the optimized preparation method allows for direct filling and use in a powder form, demonstrating excellent swelling, rapid hemostasis, and high material strength, providing long-lasting hemostasis and healing support. DETAILED DESCRIPTION

[0023] The present invention is further described below with reference to specific examples, which, however, are not intended to limit the present invention in any way. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in the art.

[0024] Unless otherwise specified, the reagents and materials used in the following examples were commercially available.

[0025] Example 1

[0026] A composite biomaterial for rapid hemostasis and bone regeneration after tooth extraction, the raw materials of which include: dialdehyde starch, chitosan-catechol, gelatin, and a responsive material PEG-SS loaded with PRP.

[0027] The preparation method comprises the following steps:

[0028] 1. Preparation of dialdehyde starch:

[0029] 2 g of dialdehyde starch was dissolved in 100 mL of PBS buffer and stirred at 60° C. for 12 hours to prepare a 2% solution.

[0030] 2. Preparation of chitosan-catechol solution:

[0031] 2 g of chitosan-catechol was dissolved in 100 mL of PBS buffer to prepare a 2% chitosan-catechol solution.

[0032] 3. Preparation of gelatin solution:

[0033] Dissolve 10 g of gelatin in 100 mL of pure water and stir at 50°C for 1 hour to prepare a 10% solution.

[0034] 4. Preparation of Responsive PRP Release Carriers:

[0035] 0.2 g PRP and 0.8 g PEG-SS were dissolved in 10 mL PBS buffer, stirred at 4 °C for 24 h, centrifuged at 8000 rpm for 10 min, and the precipitate was collected and freeze-dried to obtain PEG-SS@PRP.

[0036] 5. Preparation of powder:

[0037] 0.5 g of PEG-SS@PRP powder was placed in a beaker, and then 5 mL of gelatin solution, 5 mL of chitosan-catechol, and 10 mL of dialdehyde starch solution were dripped into the beaker at a rate of 5 mL / min, assisted by mechanical stirring at 500 rpm / min. After all the liquids were completely dripped, stirring was continued for 30 minutes to ensure that all the components were completely mixed. The stirring was removed and the mixture was left to stand at room temperature for 24 hours to form a gel.

[0038] The completely gelled colloid is freeze-dried and then crushed in a mechanical grinder. The particle size of the crushed material is controlled to be within the range of 100-200 microns. The crushed material is sieved using 100 mesh and 200 mesh screens to ensure that the powder particle size distribution is uniform and reaches the target particle size range.

[0039] Example 2

[0040] A composite biomaterial for rapid hemostasis and bone regeneration after tooth extraction, the raw materials of which include: dialdehyde starch, chitosan-catechol, gelatin, and a responsive material PEG-SS loaded with PRP.

[0041] The preparation method comprises the following steps:

[0042] 1. Preparation of dialdehyde starch:

[0043] 5 g of dialdehyde starch was dissolved in 100 mL of PBS buffer and stirred at 70° C. for 12 hours to prepare a 5% solution.

[0044] 2. Preparation of chitosan-catechol solution:

[0045] 3.5 g of chitosan-catechol was dissolved in 100 mL of PBS buffer to prepare a 3.5% chitosan-catechol solution.

[0046] 3. Preparation of gelatin solution:

[0047] Dissolve 15 g of gelatin in 100 mL of pure water and stir at 50°C for 1 hour to prepare a 15% solution.

[0048] 4. Preparation of Responsive PRP Release Carriers:

[0049] 0.2 g PRP and 1 g PEG-SS were dissolved in 10 mL PBS buffer, stirred at 4 °C for 24 h, centrifuged at 10,000 rpm for 15 min, and the precipitate was collected and freeze-dried to obtain PEG-SS@PRP.

[0050] 5. Preparation of powder:

[0051] 0.8 g of PEG-SS@PRP powder was placed in a beaker, and then 5 mL of gelatin solution, 5 mL of chitosan-catechol, and 10 mL of dialdehyde starch solution were dripped into the beaker at a rate of 5 mL / min, assisted by mechanical stirring at 500 rpm / min. After all the liquids were completely dripped, stirring was continued for 30 minutes to ensure that all the components were completely mixed. The stirring was removed and the mixture was left to stand at room temperature for 24 hours to form a gel.

[0052] The completely gelled colloid is freeze-dried and then crushed in a mechanical grinder. The particle size of the crushed material is controlled to be within the range of 100-200 microns. The crushed material is sieved using 100 mesh and 200 mesh screens to ensure that the powder particle size distribution is uniform and reaches the target particle size range.

[0053] Example 3

[0054] A composite biomaterial for rapid hemostasis and bone regeneration after tooth extraction, the raw materials of which include: dialdehyde starch, chitosan-catechol, gelatin, and a responsive material PEG-SS loaded with PRP.

[0055] The preparation method comprises the following steps:

[0056] 1. Preparation of dialdehyde starch:

[0057] 8 g of dialdehyde starch was dissolved in 100 mL of PBS buffer and stirred at 90° C. for 10 hours to prepare an 8% solution.

[0058] 2. Preparation of chitosan-catechol solution:

[0059] 5 g of chitosan-catechol was dissolved in 100 mL of PBS buffer to prepare a 5% chitosan-catechol solution.

[0060] 3. Preparation of gelatin solution:

[0061] Dissolve 20 g of gelatin in 100 mL of pure water and stir at 50°C for 1 hour to prepare a 20% solution.

[0062] 4. Preparation of Responsive PRP Release Carriers:

[0063] 0.2 g PRP and 1 g PEG-SS were dissolved in 10 mL PBS buffer, stirred at 4 °C for 24 h, centrifuged at 10,000 rpm for 15 min, and the precipitate was collected and freeze-dried to obtain PEG-SS@PRP.

[0064] 5. Preparation of powder:

[0065] 1 g of PEG-SS@PRP powder was placed in a beaker, and then 5 mL of gelatin solution, 5 mL of chitosan-catechol, and 10 mL of dialdehyde starch solution were dripped into the beaker at a rate of 5 mL / min, assisted by mechanical stirring at 500 rpm / min. After all the liquids were completely dripped, stirring was continued for 30 minutes to ensure that all the components were completely mixed. The stirring was removed and the mixture was left to stand at room temperature for 24 hours to form a gel.

[0066] The completely gelled colloid is freeze-dried and then crushed in a mechanical grinder. The particle size of the crushed material is controlled to be within the range of 100-200 microns. The crushed material is sieved using 100 mesh and 200 mesh screens to ensure that the powder particle size distribution is uniform and reaches the target particle size range.

[0067] Comparative Example 1

[0068] A composite biomaterial for rapid hemostasis and bone regeneration after tooth extraction, the raw materials of which include chitosan-catechol and gelatin.

[0069] The preparation method comprises the following steps:

[0070] 1. Preparation of chitosan-catechol solution:

[0071] 25 g of chitosan-catechol was dissolved in 100 mL of PBS buffer to prepare a 5% chitosan-catechol solution.

[0072] 2. Preparation of gelatin solution:

[0073] Dissolve 20 g of gelatin in 100 mL of pure water and stir at 50°C for 1 hour to prepare a 20% solution.

[0074] 3. Mixing and molding of hemostatic materials:

[0075] 5 mL of gelatin solution and 5 mL of chitosan-catechol were dripped into the beaker at a rate of 5 mL / min, assisted by mechanical stirring at 500 rpm / min. After all the liquid was completely dripped, stirring was continued for 30 minutes to ensure that all components were completely mixed. The stirring was removed and the mixture was allowed to stand at room temperature for 24 hours to form a gel.

[0076] The completely gelled colloid is freeze-dried and then crushed in a mechanical grinder. The particle size of the crushed material is controlled to be within the range of 100-200 microns. The crushed material is sieved using 100 mesh and 200 mesh screens to ensure that the powder particle size distribution is uniform and reaches the target particle size range.

[0077] Comparative Example 2

[0078] A composite biomaterial for rapid hemostasis and bone regeneration after tooth extraction, the raw materials of which include dialdehyde starch and chitosan-catechol.

[0079] The preparation method comprises the following steps:

[0080] 1. Preparation of dialdehyde starch:

[0081] 8 g of dialdehyde starch was dissolved in 100 mL of PBS buffer and stirred at 90° C. for 10 hours to prepare an 8% solution.

[0082] 2. Preparation of chitosan-catechol solution:

[0083] 5 g of chitosan-catechol was dissolved in 100 mL of PBS buffer to prepare a 5% chitosan-catechol solution.

[0084] 3. Preparation of powder:

[0085] 5 mL of chitosan-catechol and 10 mL of dialdehyde starch solution were dripped into the beaker at a rate of 5 mL / min, assisted by mechanical stirring at 500 rpm / min. After all the liquid was completely dripped, stirring was continued for 30 minutes to ensure that all the components were completely mixed. The stirring was removed and the mixture was allowed to stand at room temperature for 24 hours to form a gel.

[0086] The completely gelled colloid is freeze-dried and then crushed in a mechanical grinder. The particle size of the crushed material is controlled to be within the range of 100-200 microns. The crushed material is sieved using 100 mesh and 200 mesh screens to ensure that the powder particle size distribution is uniform and reaches the target particle size range.

[0087] Comparative Example 3

[0088] A composite biomaterial for rapid hemostasis and bone regeneration after tooth extraction, the raw materials of which include dialdehyde starch and gelatin.

[0089] The preparation method comprises the following steps:

[0090] 1. Preparation of dialdehyde starch:

[0091] 8 g of dialdehyde starch was dissolved in 100 mL of PBS buffer and stirred at 90° C. for 10 hours to prepare an 8% solution.

[0092] 2. Preparation of gelatin solution:

[0093] Dissolve 20 g of gelatin in 100 mL of pure water and stir at 50°C for 1 hour to prepare a 20% solution.

[0094] 3. Preparation of powder:

[0095] 5 mL of gelatin solution and 10 mL of dialdehyde starch solution were dripped into the beaker at a rate of 5 mL / min, assisted by mechanical stirring at 500 rpm / min. After all the liquids were completely dripped, stirring was continued for 30 minutes to ensure that all the ingredients were completely mixed. The stirring was removed and the mixture was allowed to stand at room temperature for 24 hours to form a gel.

[0096] The completely gelled colloid is freeze-dried and then crushed in a mechanical grinder. The particle size of the crushed material is controlled to be within the range of 100-200 microns. The crushed material is sieved using 100 mesh and 200 mesh screens to ensure that the powder particle size distribution is uniform and reaches the target particle size range.

[0097] Comparative Example 4

[0098] A composite biomaterial for rapid hemostasis and bone regeneration after tooth extraction, the raw materials of which include dialdehyde starch, chitosan-catechol, and gelatin.

[0099] The preparation method comprises the following steps:

[0100] 1. Preparation of dialdehyde starch:

[0101] 8 g of dialdehyde starch was dissolved in 100 mL of PBS buffer and stirred at 90° C. for 10 hours to prepare an 8% solution.

[0102] 2. Preparation of chitosan-catechol solution:

[0103] 5 g of chitosan-catechol was dissolved in 100 mL of PBS buffer to prepare a 5% chitosan-catechol solution.

[0104] 3. Preparation of gelatin solution:

[0105] Dissolve 20 g of gelatin in 100 mL of pure water and stir at 50°C for 1 hour to prepare a 20% solution.

[0106] 4. Preparation of powder:

[0107] 5 mL of gelatin solution, 5 mL of chitosan-catechol, and 10 mL of dialdehyde starch solution were dripped into the beaker at a rate of 5 mL / min, assisted by mechanical stirring at 500 rpm / min. After all the liquids were completely dripped, stirring was continued for 30 minutes to ensure that all the components were completely mixed. The stirring was removed and the mixture was allowed to stand at room temperature for 24 hours to form a gel.

[0108] The completely gelled colloid is freeze-dried and then crushed in a mechanical grinder. The particle size of the crushed material is controlled to be within the range of 100-200 microns. The crushed material is sieved using 100 mesh and 200 mesh screens to ensure that the powder particle size distribution is uniform and reaches the target particle size range.

[0109] Comparative Example 5

[0110] A composite biomaterial for rapid hemostasis and bone regeneration after tooth extraction, the raw materials of which include dialdehyde starch, chitosan-catechol, and gelatin.

[0111] The preparation method comprises the following steps:

[0112] 1. Preparation of dialdehyde starch:

[0113] 8 g of dialdehyde starch was dissolved in 100 mL of PBS buffer and stirred at 90° C. for 10 hours to prepare an 8% solution.

[0114] 2. Preparation of chitosan-catechol solution:

[0115] 5 g of chitosan-catechol was dissolved in 100 mL of PBS buffer to prepare a 5% chitosan-catechol solution.

[0116] 3. Preparation of gelatin solution:

[0117] Dissolve 20 g of gelatin in 100 mL of pure water and stir at 50°C for 1 hour to prepare a 20% solution.

[0118] 4. Preparation of powder:

[0119] 0.2 g of PRP solution was placed in a beaker, and then 5 mL of gelatin solution, 5 mL of chitosan-catechol, and 10 mL of dialdehyde starch solution were dripped into the beaker at a rate of 5 mL / min, assisted by mechanical stirring at 500 rpm / min. After all the liquids were completely dripped, stirring was continued for 30 minutes to ensure that all the components were completely mixed. The stirring was removed and the mixture was allowed to stand at room temperature for 24 hours to form a gel.

[0120] The completely gelled colloid is freeze-dried and then crushed in a mechanical grinder. The particle size of the crushed material is controlled to be within the range of 100-200 microns. The crushed material is sieved using 100 mesh and 200 mesh screens to ensure that the powder particle size distribution is uniform and reaches the target particle size range.

[0121] Comparative Example 6

[0122] Absorbent gelatin sponge produced by Jiangxi Xiangen Medical Technology Development Co., Ltd.

[0123] Performance testing:

[0124] 1. Determination of hemostasis time

[0125] Experimental Methods: A rat tail vein incision model was used to simulate post-tooth extraction bleeding. Hemostatic powder was applied directly to the bleeding site, and a timer was recorded to measure the time required for complete cessation of bleeding. Both the experimental and control groups underwent the same test. Multiple replicates were performed to determine statistical significance, and the average time to hemostasis was recorded.

[0126] Table 1 Hemostatic effect test results

[0127]

[0128] The test results are shown in Table 1. In Examples 1-3, as the ratio of dialdehyde starch, chitosan-catechol, and gelatin increased, the hemostatic effect was enhanced and the amount of bleeding was reduced. Furthermore, combining the results of Example 3 with those of Comparative Examples 1-3, it can be seen that dialdehyde starch, chitosan-catechol, and gelatin all have a certain promoting effect on the hemostatic effect, and the three ingredients work together to reduce the time it takes to stop bleeding and the amount of bleeding. Furthermore, compared to the commercially available gelatin sponge of Comparative Example 6, the samples of the present invention have a more rapid hemostatic effect.

[0129] 2. Material stability

[0130] Experimental Method: 200 mg of dry composite material powder was added to 100 μL of PBS buffer to allow complete gelation. The sample was placed in a container containing PBS buffer (pH 7.4) and allowed to stand in a 37°C water bath for 8 hours to simulate the human oral environment. After swelled with water, the sample was pressed with a 5g weight for 5 minutes to simulate the pressure in the oral environment and the structural integrity of the material was observed. The morphology of the material after swelled with water was visually observed, and any signs of sample disintegration, excessive softening, or surface cracks were noted.

[0131] Table 2 Material stability test results

[0132]

[0133] The test results are shown in Table 2. Examples 1-3 exhibit significant stability due to the optimal blend ratio of dialdehyde starch, chitosan-catechol, and gelatin. Comparative Example 1, lacking dialdehyde starch as a crosslinker, exhibits structural instability, rapidly disintegrating under pressure after swelling due to water absorption. Comparative Examples 2 and 3, lacking gelatin and chitosan-catechol, respectively, exhibited slight disintegration and microcracks, demonstrating that the combination of these three ingredients is essential for maintaining the stability of the hemostatic gel.

[0134] 3. Release time of growth factor PDGF in PRP

[0135] Experimental Method: 200 mg of powder was premixed with 100 μL of PBS buffer to form a gel. The gel was then placed in PBS, PBS containing 1% hydrogen peroxide (H2O2), and PBS containing 0.1% hydrogen peroxide (H2O2). The maximum release time of PDGF from PRP was recorded.

[0136] Table 3 Release time of growth factor PDGF in PRP

[0137] Example 3 Comparative Example 5 PBS 28 days 5 days <![CDATA[PBS(1%H2O2)]]> 5 days 2 days <![CDATA[PBS(0.1%H2O2)]]> 12 days 3 days

[0138] The test results, shown in Table 3, show that PEG-SS-encapsulated PRP can achieve long-term sustained release in a PBS environment. In a hydrogen peroxide environment, the release rate is accelerated due to the generation of ROS; the higher the ROS, the faster the release rate. This demonstrates that PEG-SS@PRP can achieve controlled release in response to ROS after injury.

[0139] 4. Bone regeneration effect (Micro-CT bone volume)

[0140] Experimental Methods: 200 mg of powder was premixed with 100 μL of PBS buffer to form an implantable gel. Rats were anesthetized with an intraperitoneal injection of sodium pentobarbital. After ensuring adequate anesthesia, the back hair was shaved and disinfected. A small subcutaneous incision was made at the designated location, and the subcutaneous tissue was separated to form an implant cavity. The material was placed within the cavity and the incision was sutured. Postoperatively, the rats were placed on a warming pad to recover from anesthesia and closely observed. Antibiotics were administered as needed to prevent infection. Eight weeks after implantation, samples containing the osteogenic material and surrounding tissue were removed and fixed in 4% paraformaldehyde solution. The fixed samples were then placed in a Micro-CT sample tube to ensure sample stability and scanned 360° at a resolution of 10-20 μm. After scanning, the image data was reconstructed three-dimensionally. The newly formed bone area was segmented on the reconstructed images, and bone density, newly formed bone volume (BV), and total scan volume (TV) were measured. Finally, the BV / TV ratio was used to quantify the effect of ectopic osteogenesis.

[0141] Table 4 Bone regeneration effect test results

[0142]

[0143]

[0144] The test results are shown in Table 4. The data show that the osteogenic effect of Example 3 with sustained release of PRP is significantly better than that of Comparative Example 5 with sudden release of PRP, and is even better than the commercially available gelatin sponge in the comparative example.

[0145] 5. Biocompatibility (cell viability)

[0146] Experimental Methods: Cytotoxicity experiments were conducted using mouse fibroblasts (L929). The cells were incubated with the material extract. After 24 hours of incubation, cell viability was assessed using CCK-8 reagent. The experiment was repeated three times, and the results were averaged. The cell viability of the experimental group was compared with that of the control group to assess the biocompatibility of the material.

[0147] Table 5 Cell viability test results

[0148]

[0149] The test results are shown in Table 5. Examples 1-3 and Comparative Examples 1 and 5 all exhibited high cell viability (>90%), demonstrating good biocompatibility and suitability for biomedical applications. Comparative Examples 2-6 showed slightly lower cell viability. This may be due to the protective effect of gelatin and PRP on cell survival.

[0150] 6. Antibacterial properties

[0151] Experimental method: The material is placed on a culture medium containing bacteria (such as Escherichia coli and Staphylococcus aureus). After incubation for 24 hours, the inhibition zone around the material is observed. The antibacterial performance of the material is quantitatively evaluated by measuring the diameter of the inhibition zone.

[0152] Table 6 Antibacterial performance test results

[0153]

[0154] The test results are shown in Table 6. As the dosage of dialdehyde starch, chitosan-catechol and gelatin increases, the area of ​​the inhibition zone increases. Chitosan-catechol has the greatest antibacterial effect, and other components such as gelatin and dialdehyde starch also contribute to a certain extent.

[0155] From the above, it can be seen that the composite material prepared by compounding dialdehyde starch, chitosan-catechol and gelatin in the embodiment of the present invention has good gel properties after swelling and has excellent hemostatic effect. In addition, it is combined with the introduced PRP-loaded smart response material PEG-SS, which has a sustained release effect and can promote bone regeneration. The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the various technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present invention, several variations and improvements can be made, which all belong to the scope of protection of the present invention. Therefore, the scope of protection of the patent of the present invention shall be based on the attached claims.

Claims

1. A composite biomaterial for rapid hemostasis and bone regeneration after tooth extraction, characterized in that: The raw materials include: dialdehyde starch, chitosan-catechol, gelatin, and a response material PEG-SS loaded with PRP.

2. The composite biomaterial according to claim 1, characterized in that The PRP-loaded response material PEG-SS is obtained by dispersing PRP and the response material PEG-SS in a solvent, stirring the dispersion uniformly, and then centrifuging and freeze-drying.

3. The composite biomaterial according to claim 2, characterized in that The mass ratio of PRP to the response material PEG-SS is 1:4~5.

4. The composite biomaterial according to claim 1, characterized in that The composite biomaterial is a powder prepared by freeze-drying the gel prepared from the raw materials.

5. The composite biomaterial according to claim 4, characterized in that The gel contains, according to mass volume concentration, 1-4% dialdehyde starch, 0.5-1.25% chitosan-catechol, 2.5-5% gelatin, and 2.5-5% PEG-SS, a response material loaded with PRP.

6. The composite biomaterial according to claim 4, characterized in that The particle size of the composite biomaterial is 100-200 microns.

7. The method for preparing a composite biomaterial according to any one of claims 1 to 6, characterized in that: Including steps: The gelatin solution, chitosan-catechol solution and dialdehyde starch solution were mixed, and the mixture was dropped into the responsive material PEG-SS loaded with PRP, stirred evenly, and then allowed to stand to obtain the gel.

8. The preparation method according to claim 7, characterized in that The gelatin solution, chitosan-catechol solution and dialdehyde starch solution are prepared by dissolving gelatin, chitosan-catechol and dialdehyde starch in pure water or PBS buffer respectively.

9. The preparation method according to claim 7, characterized in that The concentration of the dialdehyde starch solution is 0.02-0.08 g / mL; the concentration of the chitosan-catechol solution is 0.02-0.05 g / mL; and the concentration of the gelatin solution is 0.1-0.2 g / mL.

10. The preparation method according to claim 7, characterized in that: According to the volume ratio, gelatin solution: chitosan-catechol solution: dialdehyde starch solution = 1:1:2.

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