Bone repair material, preparation method therefor, and use thereof

Abstract

Provided are a bone repair material, a preparation method therefor, and use thereof. The bone repair material is prepared by printing with a material slurry by means of a photocuring 3D printing method and then sintering. The material slurry comprises the following components: 55-65% by mass of bioactive glass, 30-40% by mass of photosensitive resin, 1-5% by mass of a dispersing agent, and 0.1-1% by mass of a photoinitiator. The bone repair material has excellent biocompatibility and relatively high porosity, with the hemolysis rate lower than 5% and the cytotoxicity less than 30%. In addition, the bone repair material has relatively good morphology and relatively superior mechanical properties, and thus can be used as a bone repair scaffold material.

Description

Bone repair material and its preparation method and application Technical Field

[0001] The present invention relates to the field of materials, and in particular to a bone repair material and a preparation method and application thereof. Background Art

[0002] Bone repair procedures such as bone transplantation and bone fusion are among the most commonly used surgical methods in orthopedics to promote bone regeneration. In all clinical transplants, the primary sources of bone repair materials are autologous bone, allogeneic bone, animal-derived allogeneic bone, and various bone repair substitutes. Autologous bone is the gold standard and offers the best repair results, but its availability is limited and can cause secondary damage. Allogeneic and animal-derived allogeneic bone offer inferior repair results compared to autologous bone and carry the risk of rejection and disease transmission. Therefore, bone repair substitutes have become a research hotspot. In 1969, Hench et al. discovered that bioglass, as a bone repair material, can directly chemically bond with bone. This is the first artificial bioactive bone repair material, later known as 45S5 bioglass. The essential characteristic of bioactive materials is that they contain bioactive components that elicit favorable biological responses in physiological environments. Once implanted in the body, these materials can induce specific biological responses at the material-tissue interface, forming a close bond with tissue. Consequently, these materials have been extensively studied. Bioglass is a type of "bioactive material" with excellent biocompatibility and biodegradability. However, its practical application still faces many limitations. For example, when forming bioglass into bone scaffold structures, the traditional mold method can produce the desired bone shape, but it cannot produce scaffolds with complex structures, such as those with numerous small internal pores. Furthermore, the mold manufacturing process used in the traditional mold method is cumbersome, and a single mold can only produce scaffolds with specific structures. Changing the scaffold structure requires replacing or modifying the mold, which greatly limits the application of bone scaffolds produced using the traditional mold method.

[0003] Summary of the Invention

[0004] In order to overcome the problems existing in the prior art, one of the objectives of the present invention is to provide a bone repair material.

[0005] A second object of the present invention is to provide a method for preparing a bone repair material.

[0006] A third object of the present invention is to provide an application of a bone repair material in the preparation of a bone transplant material.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is:

[0008] The first aspect of the present invention provides a bone repair material, which is made by sintering a material slurry after printing using a photocuring 3D printing method. The material slurry includes the following components in mass percentage: 55-65% bioactive glass; 30-40% photosensitive resin; 1-5% dispersant; 0.1-1% photoinitiator. The various components in the material slurry of the present invention interact with each other to achieve an appropriate degree of solidification of the bone repair material, thereby ensuring that the bone repair scaffold has a high porosity on the one hand and good mechanical strength on the other. In addition, the amount and type of photosensitive resin in the present invention can enable the bone repair scaffold blank to be better degreased and sintered during the sintering process, thereby obtaining a bone repair material with excellent mechanical properties.

[0009] Preferably, based on the total mass percentage of the material slurry as 100%, the mass percentage of the bioactive glass is 56-64%; further preferably, the mass percentage of the bioactive glass is 57-63%; still further preferably, the mass percentage of the bioactive glass is 58-62%; and even further preferably, the mass percentage of the bioactive glass is 59-61%.

[0010] Preferably, the bioactive glass comprises the following components: 5-7 mol% Na2O, 7-9 mol% K2O, 7-9 mol% MgO, 15-17 mol% CaO, 5-7 mol% SrO, 26-28 mol% SiO2, 26-28 mol% B2O3, and 1-3 mol% P2O5.

[0011] In the present invention, bioactive glass (BAG) refers to a material capable of repairing, replacing, and regenerating the body, and capable of forming bonds between tissues and materials. Discovered by Hench in 1969, BAG is a silicate glass composed of SiO2, Na2O, CaO, and P2O5. The degradation products of bioactive glass can promote the production of growth factors, promote cell proliferation, enhance gene expression in osteoblasts, and increase bone tissue growth. It is the only artificial biomaterial to date that can simultaneously bond with bone tissue and connect with soft tissue. The main components of bioactive glass are SiO2, Na2O, CaO, and P2O5. Furthermore, trace elements can be added to bioactive glass to achieve different functions. For example, the addition of strontium to bioactive glass, i.e., strontium-doped bioactive glass, can promote macrophage polarization toward M2, regulate macrophage secretion, and promote osteogenesis, further enhancing the bone repair efficacy of bioactive glass.

[0012] Preferably, based on the total mass percentage of the material slurry as 100%, the mass percentage of the photosensitive resin is 32-40%; further preferably, the mass percentage of the photosensitive resin is 32-38%; further preferably, the mass percentage of the photosensitive resin is 34-38%; further preferably, the mass percentage of the photosensitive resin is 36-38%.

[0013] In the present invention, photosensitive resin refers to a material used in photocurable rapid prototyping. It is a liquid photocurable resin, also known as liquid photosensitive resin, primarily composed of an oligomer, a photoinitiator, and a diluent. Photosensitive resin is a colloidal substance composed of macromolecules. These macromolecules resemble scattered, chain-like, cross-linked fragments of a fence net. Under ultraviolet light, these macromolecules combine to form long, cross-linked polymers. During this bonding, the polymer transforms from a colloidal resin into a hard substance.

[0014] Preferably, the mass percentage of the dispersant is 1-4% based on the total mass percentage of the material slurry as 100%; more preferably, the mass percentage of the dispersant is 1-3%; and even more preferably, the mass percentage of the dispersant is 2-3%. The function of the dispersant is to evenly disperse the photosensitive resin, bioactive glass, and photoinitiator components, thereby achieving higher uniformity, more uniform surface morphology, more uniform cross-linking, and more uniform strength and hardness of the prepared bone repair material.

[0015] Preferably, based on the total mass percentage of the material slurry as 100%, the mass percentage of the photoinitiator is 0.2-0.1%; more preferably, the mass percentage of the photoinitiator is 0.2-0.8%; even more preferably, the mass percentage of the photoinitiator is 0.2-0.6%; and even more preferably, the mass percentage of the photoinitiator is 0.4-0.6%. Photoinitiators, also known as photosensitizers or photocuring agents, are compounds that can absorb energy of a certain wavelength in the ultraviolet region (250-420nm) or visible light region (400-800nm), generating free radicals, cations, etc., thereby initiating polymerization, cross-linking, and curing of monomers.

[0016] Preferably, the cytotoxicity of the bone repair material is less than 30%.

[0017] Preferably, the hemolysis rate of the bone repair material is less than 5%.

[0018] Preferably, the surface of the bone repair material has a honeycomb porous structure. The internal connectivity of the pores in the bone repair material of the present invention is not less than 95% to meet the exchange of substances between cells and the external environment. The internal connectivity in the present invention refers to the internal through-hole structure of the printed bone repair material with a certain distribution pattern according to the design of the printing model. The connectivity between the through-holes in the bone repair material is the internal connectivity. If the internal connectivity of the bone repair material is 100%, it means that all through-holes in the material are connected and no blockage occurs.

[0019] Preferably, the surface of the bone repair material is distributed with pores with a pore size of 450 to 550 μm. If the pore size of the bone repair material is less than 450 μm, the pores on the surface of the bone repair material are easily blocked during sintering, making the sintered bone repair material unusable.

[0020] The second aspect of the present invention provides a method for preparing the bone repair material provided by the first aspect of the present invention, comprising the following steps:

[0021] S1: Printing the material slurry into a bone repair material blank according to the designed structural model using a light-curing 3D printing method;

[0022] S2: sintering the bone repair material green body to obtain the bone repair material.

[0023] Preferably, the material slurry is prepared by mixing bioactive glass, photosensitive resin, dispersant and photoinitiator and ball milling the mixture.

[0024] Preferably, the light-curing 3D printing method comprises the following steps: adding the material slurry to the resin tank of a light-curing printer, inserting the designed structural model into the printer, adjusting the position of the printer scraper and moving the scraper, and then lowering the printing platform and printing. The light-curing 3D printing method of the present invention can ensure both printing accuracy and mechanical strength of the printed bone repair material by adjusting the printing parameters. During printing, various printing parameters need to be adjusted to improve printing accuracy, such as the printing current, exposure time, and number of printing layers.

[0025] Further preferably, the photocuring 3D printing method is specifically as follows: placing the material slurry into the resin tank of the photocuring printer, importing the designed structural model into the printer, setting the printer parameters, then adjusting the position of the printer scraper and moving the scraper, and then lowering the printing platform and performing layered printing.

[0026] Preferably, the step of setting the printer parameters specifically includes setting the x-axis accuracy to 0.05-0.07mm, the y-axis accuracy to 0.04-0.06mm, the exposure time to 9-11s, and the scraper displacement speed to 90-110mm / s. If the exposure time is less than 9s, the curing thickness is insufficient, a gap is generated between the forming plate and the material trough, and printing is interrupted. If the exposure time is greater than 11s, the long exposure time causes overexposure, the curing thickness is too thick, and the printed sample is too high.

[0027] Preferably, the preparation method further comprises the step of clearing the holes on the bone repair material blank, which step is located after step S1 and before step S2.

[0028] Preferably, the preparation method further comprises the step of removing the material slurry on the bone repair material blank, which step is located after step S1 and before step S2.

[0029] Preferably, the cleaning step uses alcohol cleaning.

[0030] Preferably, the sintering step is: first sintering the bone repair material body once, and then sintering it twice; further preferably, the sintering step is: first sintering the bone repair material body once, then letting it stand for 5 to 24 hours, and then sintering it twice.

[0031] Preferably, the primary sintering step is: first heating to 480-520°C at a heating rate of 1-3°C / min and holding for 160-240 min, then heating to 530-570°C and holding for 70-120 min; then cooling to 280-320°C at a cooling rate of 1-3°C / min, and then naturally cooling; further preferably, the primary sintering step is: first heating to 490-510°C at a heating rate of 1-3°C / min and holding for 170-200 min, then heating to 540-560°C and holding for 80-100 min; then cooling to 290-310°C at a cooling rate of 1-3°C / min, and then naturally cooling.

[0032] Preferably, the heating rate in the primary sintering step is 1.5-2.5° C. / min.

[0033] Preferably, the secondary sintering step is: first heating to 530-570°C at a heating rate of 1-3°C / min and holding for 60-100 min, then heating to 580-620°C and holding for 70-120 min, then cooling to 280-320°C at a cooling rate of 1-3°C / min, and then naturally cooling; further preferably, the secondary sintering step is: first heating to 540-560°C at a heating rate of 1-3°C / min and holding for 70-90 min, then heating to 590-610°C and holding for 80-100 min, then cooling to 290-310°C at a cooling rate of 1-3°C / min, and then naturally cooling.

[0034] Preferably, the heating rate in the secondary sintering step is 1.5-2.5° C. / min.

[0035] Preferably, the volume shrinkage rate of the bone repair material after sintering is 40-50% compared with the volume of the bone repair material body; further preferably, the volume shrinkage rate of the bone repair material after sintering is 43-47% compared with the volume of the bone repair material body; even further preferably, the volume shrinkage rate of the bone repair material after sintering is 44-46% compared with the volume of the bone repair material body.

[0036] The third aspect of the present invention provides use of the bone repair material provided in the first aspect of the present invention in preparing a bone transplant material.

[0037] The present invention has the following beneficial effects: the bone repair material is made of bioactive glass, which exhibits bioactivity that promotes bone repair growth and has good biocompatibility. Furthermore, the light-curing 3D printing method allows for the printing of bone repair materials with high porosity, thereby promoting the growth of blood vessels, cells, and new bone on the bone repair material. Furthermore, the bone repair material has been tested to have a hemolysis rate of less than 5% and a cytotoxicity of less than 30%. It also exhibits a relatively uniform surface morphology and a high degree of cross-linking. Consequently, the bone repair material possesses excellent mechanical properties and can be used as a bone repair scaffold material.

[0038] The bone repair material described in this invention utilizes a light-curing 3D printing method to directly print a material slurry. This simple and easy-to-use process allows for the printing of multiple bone repair materials in a single batch, resulting in high production efficiency, high printing efficiency and precision, and a high yield rate for finished products. Furthermore, the method enables rapid and precise customization of bone repair materials, allowing for efficient tailoring to individual patient needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] FIG1 is a physical picture and SEM picture of the bone repair scaffold in Example 1.

[0040] FIG2 is a graph showing the CCK-8 cytotoxicity test of the bone repair scaffold in Example 1.

[0041] FIG3 is a graph showing the compressive strength test of the bone repair scaffolds after sintering in Example 1 and Comparative Example 1.

[0042] FIG4 is a light transmittance test diagram of the bone repair scaffold in Example 1 at two different test angles. DETAILED DESCRIPTION

[0043] The specific implementation of the present invention will be further described in detail below in conjunction with the accompanying drawings and examples, but the implementation and protection of the present invention are not limited thereto. It should be noted that if there are any processes that are not particularly described in detail below, they can be implemented or understood by those skilled in the art with reference to the prior art. The reagents or instruments used that do not indicate the manufacturer are all conventional products that can be purchased commercially.

[0044] The present invention studies the use of digital light processing (DLP) solidification molding three-dimensional printing method (i.e., light-curing 3D printing method) to first print and solidify the material slurry and then sinter it at high temperature to prepare a three-dimensional porous active bone repair material, and conducts performance testing on it. Bioactive glass is selected as the raw material, and after mixing materials such as photosensitive resin, photoinitiator, and dispersant, a three-dimensional grid-shaped bone repair material blank is prepared by the light-curing 3D printing method, and then the bone repair material is prepared by an optimized sintering process. The present invention can print bone repair materials with complex structures and has very high printing accuracy, which is unattainable by traditional mold preparation methods, emerging foam replication methods, and melt / freeze extrusion methods. DLP light-curing 3D printing is a process of layer-by-layer light exposure and superposition. Since the thickness of each layer of material film is slightly thicker than the layer thickness, the light intensity is constant. Long exposure time will result in overexposure, resulting in a thicker solidification thickness and a higher printed sample. Short exposure time will result in insufficient solidification thickness, resulting in a gap between the forming plate and the material trough, causing printing interruption. At the same time, the first few layers need to be exposed more strongly to ensure that the sample sticks to the forming plate.

[0045] The information of the raw materials used in the examples of the present invention is as follows:

[0046] The bioactive glass used in the embodiment of the present invention is composed of the following components: 6 mol% Na2O, 8 mol% K2O, 8 mol% MgO, 16 mol% CaO, 6 mol% SrO, 27 mol% SiO2, 27 mol% B2O3, and 2 mol% P2O5.

[0047] TMPTA photosensitive resin was purchased from Tokyo Chemical Industry Development Co., Ltd. (Shanghai);

[0048] VOK-Disper 85000 dispersant was purchased from Guangzhou Si Tu Yuan Chemical Co., Ltd.;

[0049] 819 photoinitiator was purchased from Starwell (Beijing) Biotechnology Co., Ltd.

[0050] Example 1

[0051] The light-cured 3D printed bone repair scaffold in this example is made of the following raw materials in the following mass percentages: 60% bioglass powder (i.e., 1.5B6Sr bioactive glass), 37% TMPTA photosensitive resin, 2.5% VOK-Disper 85000 dispersant, and 0.5% 819 photoinitiator.

[0052] The light-curing 3D printed bone repair scaffold in this example was prepared using the following preparation method, which specifically includes the following steps:

[0053] (1) 3D printing steps

[0054] (a) First, bioglass powder, TMPTA photosensitive resin, VOK-Disper 85000 dispersant, and 819 photoinitiator are placed in a ball mill. Then, small ball milling beads of equal mass are added. The ball mill is then placed in a ball mill and milled for 6 hours to fully mix the raw materials. The ball mill is then removed from the ball mill and the ball milling beads are filtered through a sieve. The slurry in the material tray is poured into a black light-shielding bottle to prevent natural light from solidifying the slurry, thereby preparing the 3D printing slurry.

[0055] (b) Design the structure of the bone repair scaffold and slice and export the structure file for future use. The design process for the bone repair scaffold structure is as follows: Based on the patient's bone injury CT image, a 3D digital model of the bone repair scaffold is designed using 3D design software such as UG and Solidworks. This is converted to STL format and imported into Magics slicing software. The 3D digital model of the bone repair scaffold is supported and sliced. The support design thickness is 2-3 mm, and the slice thickness is 100-120 μm. The sliced ​​digital model is exported in STI format for future use.

[0056] (c) The 3D printing slurry is mixed thoroughly and poured into the 3D printer's tray. The sliced ​​digital model structure file is imported into the 3D printer. The set structure is selected, and the 3D printer is operated. The printing parameters of the 3D printer are set as follows: x-axis accuracy is set to 0.06mm, y-axis accuracy is set to 0.06mm, and z-axis accuracy is set to 0.05mm. Layered printing is performed, and the exposure time is set to 10s and the scraper displacement speed is set to 100mm / s. The position of the 3D printer scraper is then adjusted to ensure the appropriate thickness of the solidification area. The scraper is then moved back and forth to temporarily flatten the solidification area. Printing begins, and the printing platform gradually descends to contact the slurry. Solidification begins layer by layer, and the slurry slowly accumulates on the forming platform until the desired scaffold height is reached. Printing is complete, and a bone repair scaffold blank is produced.

[0057] (d) Remove the molding platform and carefully scrape off the bone repair scaffold blank on the molding platform with a knife. Wear gloves and wash away the residual liquid slurry on the bone repair scaffold blank with alcohol, and then blow dry the alcohol with an air pump.

[0058] (2) Sintering step

[0059] The pores blocked by slurry on the bone repair scaffold were cleared. The scaffold was then placed on a ceramic plate and placed in a muffle furnace. Pre-firing was performed: starting at room temperature, the temperature was raised at 2°C / min to 500°C, then held for 180 minutes. The temperature was then raised at 2°C / min to 550°C, held for 90 minutes, then lowered at 2°C / min to 300 minutes, and allowed to cool naturally to room temperature. After standing overnight, the scaffold was adjusted for orientation and sintering was performed: starting at room temperature, the temperature was raised at 2°C / min to 550°C, held for 80 minutes, then raised at 2°C / min to 600°C, held for 90 minutes, then lowered at 2°C / min to 300°C, and allowed to cool naturally to room temperature. This produced the light-curing 3D-printed bone repair scaffold used in this example.

[0060] Comparative Example 1

[0061] The bone repair scaffold in this example is made of the same raw materials as the bone repair scaffold in Example 1.

[0062] The preparation method of the bone repair scaffold in this example is different from that in Example 1 in that this example adopts a one-step sintering step, and the sintering step in this example is specifically as follows:

[0063] The holes blocked by slurry on the bone repair scaffold blank in this example were cleared. The scaffold blank was then placed on a ceramic plate and placed in a muffle furnace. The temperature was set: starting from room temperature, the temperature was raised at a rate of 2°C / min to 250°C, then at a rate of 1°C / min to 550°C, held at this temperature for 90 minutes, then raised at a rate of 1°C / min to 600°C, held at this temperature for 180 minutes, then lowered at a rate of 2°C / min to 300°C, and finally cooled naturally to room temperature. This produced the light-curing 3D-printed bone repair scaffold in this example.

[0064] Performance testing:

[0065] (1) Surface morphology test

[0066] The actual pictures of the light-cured 3D printed bone repair scaffold before and after sintering in Example 1 are shown in Figure 1(a), wherein cylinder A in Figure 1(a) is a actual picture of the bone repair scaffold before sintering (i.e., the bone repair scaffold blank), and the diameter of cylinder A is 10.64 mm and the height is 14 mm; cylinder B in Figure 1(a) is a actual picture of the bone repair scaffold after sintering, and the diameter of cylinder B is 8.3 mm and the height is 12.5 mm. The volume shrinkage rate of the bone repair scaffold before and after sintering is approximately 45%. In addition, as shown in Figure 1(a), the bone repair scaffold has relatively large holes, which can well guide the cells to grow into the bone repair scaffold. At the same time, the bone repair scaffold material can guide the cells and new bone to grow in. Then the SEM image of part of the area in Figure 1(a) was tested, and the test results are shown in Figure 1(b). The SEM image of part of the area in Figure 1(b) is shown in Figure 1(c). It can be seen from Figures 1(b) and 1(c) that the bone repair scaffold in Example 1 has uniform pores, a pore size of about 500μm, a smooth texture, uniform particle size, and uniform distribution.

[0067] (2) In vitro hemolysis test

[0068] The in vitro hemolysis experiment of the light-cured 3D printed bone repair scaffold in Example 1 was carried out according to the test method described in the industry standard YY / T 1651.1-2019. In order to eliminate the influence of pH value on the test results as much as possible, before adding rabbit blood cells, the pH of the solution was adjusted to 7.4±0.1 using dilute HCl, and then incubated in a 37°C water bath for 1 hour. After centrifugation, the supernatant was taken to measure the absorbance, and the hemolysis rate of the bone repair scaffold in Example 1 was calculated to be 1.7%. Its hemolysis rate is less than 5%, which meets the requirements for the hemolysis rate of materials implanted in the human body. If the hemolysis rate of the bone repair scaffold is higher than 5%, it will cause excessive red blood cell rupture after the bone repair scaffold enters the human body.

[0069] (3) In vitro cytotoxicity test

[0070] The cell proliferation experiment was conducted using human bone marrow mesenchymal stem cells. The toxicity of the light-cured 3D printed bone repair scaffold sample in Example 1 was tested by the leaching method. The specific test method was as follows: the leaching solution of the experimental group and the control group was prepared at an extraction ratio of 0.2 g / mL at 37°C, and then the leaching solution of the prepared experimental group was diluted 0 times, 2 times, 4 times, 8 times, 16 times, 32 times, 64 times, 100 times, 128 times, and 256 times respectively. The prepared density of 1×10 3 / mL of cell suspension was inoculated into a 96-well plate, with 100mL per well. A control group (C group) and an experimental group were set up, with at least 3 wells inoculated in each group. After culturing at 37°C for 24 hours under 5% carbon dioxide conditions, the culture medium was replaced. After culturing at 37°C in a 5% carbon dioxide incubator for 72 hours, CCK-8 was added and cultured for another hour. The absorbance was measured at 450nm on a microplate reader. The relative proliferation rate (RGR) was calculated using the absorbance of the control group as the standard. The cytotoxicity reaction level of the experimental and control group samples was judged based on the RGR. The test results are shown in Figure 2. As can be seen from Figure 2, the extract and its related series of dilutions showed high cell activity, with a cell activity decrease rate of <30%, which met the non-toxic standard.

[0071] (4) Compression performance mechanical test

[0072] The mechanical compression properties of the bone repair scaffolds in Example 1 and Comparative Example 1 were tested respectively, and the specific test results are shown in Figure 3. As shown in Figure 3, the compressive strength of the bone repair scaffold in Example 1 after sintering by the two-step sintering method is 23.8 MPa, while the compressive strength of the bone repair scaffold in Comparative Example 1 after sintering by one step is 17.4 MPa, that is, the compressive strength of the bone repair scaffold in Example 1 is significantly higher than that of the bone repair scaffold in Comparative Example 1 after sintering by one step. This may be because the effective sintering time of the two-step sintering method is longer, and the secondary sintering is conducive to the homogenization of the glass network structure.

[0073] (5) Hole internal connectivity test

[0074] The internal pore connectivity of the bone repair scaffold in Example 1 was tested using the following method: The bone repair scaffold in Example 1 was placed above a strong light source for observation and photographing. The light transmission test images at two different test angles are shown in Figure 4. If the pores are connected, light will be transmitted. If they are blocked or the material is deformed, resulting in disconnected pores, light will not be transmitted. The material was photographed from multiple angles, and the total number of pores that could transmit light was statistically calculated. The actual count was N1, and the total number of pores designed in the model itself was counted as N0. The internal pore connectivity C = N1 / N0. The average value of 5 samples from the same group was calculated. Calculations showed that the average internal pore connectivity of the bone repair scaffolds printed in the same batch of 3D printing was no less than 95%.

[0075] The bone repair scaffold of the present invention has a peripheral honeycomb porous structure and is a three-dimensional structural scaffold. The printed bone repair scaffold blank is sintered to produce a bone repair scaffold with excellent mechanical properties, good surface morphology, good biocompatibility, a hemolysis rate of less than 5%, and a cytotoxicity of less than 30%. The present invention attempted multiple sintering temperatures and sintering steps, ultimately determining the optimal maximum sintering temperature of 600°C. The sintered scaffold has a good morphology and a volume shrinkage rate of approximately 45%. After sintering, no significant deformation or fracture occurred, and the axial and radial through-holes were not significantly blocked, indicating good permeability.

[0076] While the embodiments of the present invention have been described in detail above, the present invention is not limited to the embodiments described above. Various modifications may be made within the scope of knowledge possessed by a person skilled in the art without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof may be combined with one another unless there is a conflict.

Claims

1. A bone repair material, characterized in that, the bone repair material is prepared by sintering after being printed by a photocuring 3D printing method from a material slurry; the material slurry comprises the following components in mass percentages: 55-65% of bioactive glass, 30-40% of photosensitive resin, 1-5% of dispersant, and 0.1-1% of photoinitiator.

2. The bone repair material according to claim 1, characterized in that, the cytotoxicity of the bone repair material is less than 30%; and / or, the hemolysis rate of the bone repair material is less than 5%.

3. The bone repair material according to claim 1, characterized in that, the surface of the bone repair material has a honeycomb-like porous structure; and / or, pores with a pore diameter of 450-550 μm are distributed on the surface of the bone repair material.

4. The bone repair material according to claim 3, characterized in that, the internal connectivity rate of the pores in the bone repair material is not less than 95%.

5. The bone repair material according to claim 1, characterized in that: The bioactive glass comprises the following components: 5-7 mol% of Na 2 O, 7-9 mol% of K 2 O, 7-9 mol% of MgO, 15-17 mol% of CaO, 5-7 mol% of SrO, 26-28 mol% of SiO 2 , 26-28 mol% of B 2 O 3 , 1-3 mol% of P 2 O 5 .

6. A preparation method of the bone repair material according to any one of claims 1-5, characterized in that, comprises the following steps: S1: Printing the material slurry into a bone repair material blank according to a designed structural model by a photocuring 3D printing method; S2: Sintering the bone repair material blank to obtain the bone repair material.

7. The preparation method of the bone repair material according to claim 6, characterized in that, the sintering step is: first performing primary sintering on the bone repair material blank, and then performing secondary sintering to obtain.

8. The preparation method of the bone repair material according to claim 7, characterized in that, the primary sintering step is: heating at a heating rate of 1-3 °C / min to 480-520 °C and holding for 160-240 min, then heating to 530-570 °C and holding for 70-120 min, and then cooling at a cooling rate of 1-3 °C / min to 280-320 °C, and then naturally cooling; and / or, the secondary sintering step is: heating at a heating rate of 1-3 °C / min to 530-570 °C and holding for 60-100 min, then heating to 580-620 °C and holding for 70-120 min, and then cooling at a cooling rate of 1-3 °C / min to 280-320 °C, and then naturally cooling.

9. The preparation method of the bone repair material according to claim 6, characterized in that, compared with the volume of the bone repair material blank, the volume shrinkage rate of the bone repair material after sintering treatment is 40-50%.

10. Application of the bone repair material according to any one of claims 1-5 in the preparation of a bone graft material.

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