Biological ceramic scaffold as well as preparation method and application thereof

Abstract

The invention provides a biological ceramic scaffold as well as a preparation method and application thereof, and belongs to the technical field of tissue repair materials. According to the invention, through a DLP photocuring 3D printing technology, akermanite with compressive strength similar to that of human bones and moderate degradation rate is designed into the biological ceramic scaffold for improving bone tissue repair, and the mechanical strength, porosity and scaffold structure meet the requirements of bone repair scaffolds. The novel porous biological ceramic scaffold is prepared by using a DLP photocuring 3D printing technology, the influence of scaffold form, solid content and sintering parameters on the mechanical property of the bone repair scaffold is explored, and the biological ceramic scaffold with high mechanical property and excellent bone repair effect is finally prepared.

Description

Technical Field

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

[0002] Bone defects are a medical problem caused by trauma and correction of congenital deformities. Especially in plastic surgery and dental surgery, there is a huge demand for bone substitutes in clinical practice. Autologous bone transplantation is regarded as the gold standard for clinical bone transplantation, but its donor source is limited and may cause complications such as persistent pain at the donor site. Therefore, inorganic bioceramics that mimic the formation process of calcium phosphate minerals in bone tissue have become one of the most promising options in the field of bone repair in recent years. Calcium phosphate ceramics such as hydroxyapatite (HA), biphasic calcium phosphate (BCP) and β-tricalcium phosphate (β-TCP) were introduced into clinical application more than 30 years ago because of their similar chemical properties to bone minerals. Whether in block, coating or porous form, calcium phosphate ceramics can effectively support the attachment, proliferation and differentiation of osteoblasts. However, their inherent poor degradability, unsatisfactory mechanical properties and lack of osteoinductivity limit their long-term application in the repair of load-bearing bone defects.

[0003] As a ternary ceramic containing calcium (Ca), silicon (Si) and magnesium (Mg), magnesia chalcedony (Ca2MgSi2O7) has become a calcium-silicon-based bioceramic with great potential for bone regeneration due to its superior mechanical properties and controllable degradation rate. In terms of cell bioactivity, studies have found that compared with β-TCP, magnesia chalcedony can more effectively promote the osteogenic differentiation of bone marrow-derived stromal cells and adipose-derived stem cells in vitro and increase the gene expression of osteogenic markers. In vivo animal experiments also showed that in a rabbit model, the foam-templated magnesia chalcedony porous implant can accelerate new bone formation and promote more bone regeneration compared with β-TCP. Although magnesia chalcedony as a bioceramic material for bone repair has the advantages of good biocompatibility, bone regeneration promotion and bioactivity, it also has some disadvantages, mainly insufficient mechanical properties, including low fracture toughness and brittleness, which makes magnesia chalcedony materials prone to sudden fracture when impacted or overloaded, especially in load-bearing applications, they may not be able to withstand the required mechanical load. Processing difficulty and cost issues also affect the economic feasibility of magnesia chalcedony in clinical applications. In short, in the field of bone repair materials, helping patients fill bone defects is an important task. At present, the effect of filling bone defects is not ideal, mainly because the existing reconstruction materials cannot fully meet clinical needs, such as personalized shape design, promoting new tissue growth, and the need for reconstruction materials to have certain mechanical properties to replace bone tissue before new tissue is formed. Summary of the invention

[0004] The purpose of the present invention is to provide a bioceramic scaffold and its preparation method and application. The bioceramic scaffold prepared by the method provided by the present invention has high mechanical properties and porosity, and excellent bone repair effect. In addition, the process is simple, the production cost is low, and it is suitable for large-scale production and application.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a method for preparing a bioceramic scaffold, comprising the following steps:

[0007] (1) mixing magnesia chalcedony powder and bio-based photosensitive resin, and then ball milling to obtain printing ink;

[0008] (2) The printing ink obtained in step (2) is transferred to the slurry tank of the light-curing 3D printer, and DLP 3D printing is performed according to the 3D bracket model to obtain a printed ceramic bracket.

[0009] (3) The printed ceramic scaffold obtained in step (2) is cleaned, dried and sintered in sequence to obtain a bioceramic scaffold.

[0010] Preferably, the particle size of the magnesia stone powder in step (1) is 4 to 20 μm.

[0011] Preferably, the rotation speed of the ball mill in step (1) is 500-600 rpm, and the ball milling time is 4-6 hours.

[0012] Preferably, the mass percentage of magnesia quartz powder in the printing ink in step (1) is 40% to 60%.

[0013] Preferably, the parameters of DLP 3D printing in step (2) are as follows: when printing the support body, the layer thickness of the scraper is 75-200 μm; the single layer thickness is 25-50 μm; the illumination time is 3.5-9 s; the illumination intensity is 6-9 mW / cm 2 .

[0014] Preferably, the 3D support model in step (2) is one of a 6*6 90° grid model, a 6*6 45° grid model, and a 6*6 round hole honeycomb briquette model;

[0015] The method for making the 6*6 90° grid model comprises: creating a rectangular parallelepiped model with a width of 0.4-0.5 mm, a height of 0.2-0.3 mm, and a length of 8 mm in MaterialiseMagics23.0 software, and placing the above 6 rectangular parallelepipeds with the same length, width, and height in parallel along the x-axis on the xy plane at a spacing of 0.45-0.6 mm to form a complete grid model, copying the prepared grid model by 10 of the grids along the z-axis, and each grid differs from the previous layer in the xy plane by 90° to obtain a preliminary model, and finally creating a cylinder with a height of 6 mm and a diameter of 6 mm, aligning the cylinder with the center point of the model, and using Boolean operation to obtain the 6*6 90° grid model;

[0016] The method for making a 6*6 45° grid model comprises: creating a rectangular parallelepiped model with a width of 0.4-0.5 mm, a height of 0.2-0.3 mm, and a length of 8 mm in MaterialiseMagics23.0 software, and placing the above 6 rectangular parallelepipeds with the same length, width, and height in parallel along the x-axis on the xy plane at a spacing of 0.45-0.6 mm to form a complete grid model, copying the prepared grid model by 4 of the grids along the z-axis direction, and each grid differs from the previous layer in an angle of 45° on the xy plane to obtain a model, copying the model 4 times along the z-axis to obtain a preliminary model of a 45° grid model, and finally creating a cylinder with a height of 6 mm and a diameter of 6 mm, aligning the cylinder with the center point of the model, and using a Boolean intersection operation to obtain the 6*6 45° grid model;

[0017] The method for making the 6*6 round-hole honeycomb briquettes model comprises: creating a cylinder with a diameter of 0.8-1 mm in MaterialiseMagics23.0 software, and arranging 25 of the cylinders perpendicular to the xy plane at a spacing of 0.4-0.6 mm to form a cylinder array, copying 2 arrays, and rotating 90° along the x-axis and y-axis respectively, then removing the cylinders at the 4 vertex angles of the array perpendicular to the xy plane and the adjacent cylinders to obtain a preliminary model, then creating a cylinder with a height of 6 mm and a diameter of 6 mm, aligning the cylinder with the center point of the model, and using Boolean subtraction operation to obtain the 6*6 round-hole honeycomb briquettes model.

[0018] Preferably, the drying temperature in step (3) is 50-70° C., and the drying time is 22-26 hours.

[0019] Preferably, the sintering in step (3) includes: heating the dried ceramic scaffold to 400-600°C at a rate of 2-5°C / min and then keeping it warm for 10-14 hours, then heating it to 1200-1330°C at a rate of 1-3°C / min and keeping it warm for 20-28 hours, then cooling it to 90-110°C at a rate of 8-12°C / min, and finally cooling it in the furnace to obtain a bioceramic scaffold.

[0020] The present invention also provides a bioceramic scaffold prepared by the preparation method described in the above technical solution, wherein the bioceramic scaffold comprises magnesia feldspar Ca2MgSi2O7.

[0021] The present invention also provides a bioceramic scaffold for use in bone repair, wherein the bioceramic scaffold is a bioceramic scaffold prepared by the preparation method described in the above technical solution or a bioceramic scaffold described in the above technical solution.

[0022] The present invention provides a method for preparing a bioceramic scaffold, which utilizes the good biocompatibility of magnesia chrysogenite as a raw material to improve the compatibility of the prepared bioceramic scaffold with human tissue and avoid causing a significant immune rejection reaction. The good bioactivity property enables magnesia chrysogenite to promote the proliferation and differentiation of bone cells, and significantly improves the repair effect of the prepared bioceramic scaffold on bone defects. In addition, magnesia chrysogenite can induce the formation of hydroxyapatite (HAp), a key component in the natural mineralization process of bone tissue, thereby facilitating the formation of new bone, and the degradation rate of magnesia chrysogenite is controllable, so that the bioceramic scaffold material is gradually replaced by new bone tissue in the body, which is coordinated with the natural process of bone growth. The present invention uses DLP light-curing 3D printing technology to accurately control the shape and internal structure of the scaffold to meet the needs of different patients, and can be customized to produce a porous scaffold suitable for the bone defect of each patient, and uses DLP light-curing 3D printing technology to The porosity of the bioceramic scaffold prepared by 3D printing (about 57%) is close to the optimal porosity of the scaffold for bone cell growth (60%), ensuring that there is enough space inside the scaffold for new tissue growth, and significantly improving the induction effect of the bioceramic scaffold on bone cell growth; the present invention regulates the macrostructure of the bioceramic scaffold (i.e., the scaffold morphology) according to the 3D scaffold model, controls the mass percentage of the magnesia chalcite powder in the printing ink (i.e., the solid content / solid ratio), and synergistically controls the sintering temperature and time, significantly improving the mechanical properties and porosity of the prepared bioceramic scaffold, so as to significantly improve the fracture toughness and brittleness of the bioceramic scaffold, avoid the sudden fracture of the bioceramic scaffold when it is impacted or overloaded, and increase its mechanical load; and the prepared bioceramic scaffold can also release some beneficial elements such as silicon, calcium, and magnesium, which can promote the growth of blood vessels and adipose tissue, help the scaffold to better fuse with the surrounding tissue, and further improve its bone repair effect. And the preparation method provided by the present invention has a simple process, low production cost, and is suitable for large-scale production and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The physical image and XRD diagram of the magnesia feldspar powder prepared by the sol-gel method in Example 1 of the present invention are shown in FIG. Figure 1 (a) is the actual picture. Figure 1 (b) is the XRD pattern;

[0024] Figure 2 The actual pictures of the bioceramic scaffolds prepared in Examples 1 to 3 of the present invention are shown in FIG. Figure 2 (a) above is a top view of the 90° grid bioceramic scaffold prepared in Example 1, and (a) below is a side view of the 90° grid bioceramic scaffold prepared in Example 1. Figure 2 (b) in the middle is a top view of the 45° grid bioceramic scaffold prepared in Example 2, and (b) in the bottom is a side view of the 45° grid bioceramic scaffold prepared in Example 2. Figure 2 (c) above is a top view of the round-hole bioceramic scaffold prepared in Example 3, and (c) below is a side view of the round-hole bioceramic scaffold prepared in Example 3;

[0025] Figure 3 A statistical diagram of the compressive strength of bioceramic scaffolds prepared in Examples 1 to 3 of the present invention with different geometric shapes;

[0026] Figure 4 Statistical graphs of mechanical strength of bioceramic scaffolds prepared in Examples 13, 14, 11 and Comparative Example 1 with different sintering curves of the present invention;

[0027] Figure 5 This is a physical picture of the bioceramic scaffold prepared in Comparative Example 1 of the present invention;

[0028] Figure 6 Statistical graphs of the compressive strength of the bioceramic scaffolds prepared in Examples 2, 5, 8, and 11 of the present invention at different solid phase ratios. DETAILED DESCRIPTION

[0029] The present invention provides a method for preparing a bioceramic scaffold, comprising the following steps:

[0030] (1) mixing magnesia chalcedony powder and bio-based photosensitive resin, and then ball milling to obtain printing ink;

[0031] (2) The printing ink obtained in step (2) is transferred to the slurry tank of the light-curing 3D printer, and DLP 3D printing is performed according to the 3D bracket model to obtain a printed ceramic bracket.

[0032] (3) The printed ceramic scaffold obtained in step (2) is cleaned, dried and sintered in sequence to obtain a bioceramic scaffold.

[0033] In the present invention, unless otherwise specified, the raw materials used are conventional commercial products in the art.

[0034] The invention mixes magnesia quartz powder and bio-based photosensitive resin, and then performs ball milling to obtain printing ink.

[0035] In the present invention, the magnesia quartz powder is preferably prepared by a sol-gel method or a hot melt method.

[0036] In the present invention, the preparation method of the magnesia chalcedony powder preferably comprises: adding nitric acid to deionized water, adjusting the pH value to 1.5-2, adding TEOS dropwise, performing a hydrolysis reaction until the solution is clear and transparent, then adding magnesium nitrate hexahydrate and calcium nitrate tetrahydrate, and continuously stirring for 5-7 hours to obtain a mixture; sealing the mixture at 50-60°C for 24 hours, then removing the seal for 1 hour, drying at 120°C, and sequentially grinding, roasting and post-treating to obtain magnesia chalcedony.

[0037] In the present invention, the calcination temperature is preferably 1100-1200°C; the calcination time is preferably 2-4 hours. In the present invention, the post-treatment preferably includes grinding and sieving.

[0038] In the present invention, the particle size of the magnesia chalcite powder is preferably 4 to 20 μm, more preferably 6 to 15 μm, and further preferably 10 μm. The present invention controls the particle size of the magnesia chalcite powder within the above range to avoid the particle size being too large, which will cause the ceramic scaffold to be not tightly bonded after sintering, and to avoid the particle size being too small, which will cause the final ceramic scaffold to be easily broken, and significantly improve the mechanical properties and porosity of the prepared bioceramic scaffold, so as to significantly improve the fracture toughness and brittleness of the bioceramic scaffold, avoid the bioceramic scaffold from suddenly breaking when it is impacted or overloaded, increase its mechanical load, and obtain a bioceramic scaffold with excellent comprehensive performance.

[0039] In the present invention, the bio-based photosensitive resin is preferably a conventional commercial product in the art.

[0040] In the present invention, the equipment used for the ball milling is preferably an agate ball milling jar. In the present invention, the rotation speed of the ball milling is preferably 500-600 rpm, and the time of the ball milling is preferably 4-6 hours. The present invention can make the bio-based photosensitive resin and the magnesia feldspar powder mix more fully through ball milling, so that the fluidity of the printing ink is better, which is more conducive to subsequent 3D printing.

[0041] In the present invention, the mass percentage of the magnesia quartz powder in the printing ink is preferably 40% to 60%, more preferably 45% to 58%, and further preferably 55%. The present invention controls the mass percentage of the magnesia quartz powder in the printing ink (i.e., the solid ratio) within the above range, adjusts the viscosity of the printing ink, facilitates the smooth printing, and prints a ceramic scaffold with a complete structure that is not easy to break after sintering, significantly improves the mechanical properties and porosity of the prepared bioceramic scaffold, and significantly improves the fracture toughness and brittleness of the bioceramic scaffold, avoids the sudden breakage of the bioceramic scaffold when it is impacted or overloaded, increases its mechanical load, avoids the magnesia quartz scaffold prepared at a ratio lower than the above solid ratio, and is easy to break after sintering, damaging the integrity of the structure, and avoids the ceramic slurry prepared at a ratio higher than the above solid ratio, which is too viscous and cannot be printed smoothly.

[0042] After obtaining the printing ink, the present invention transfers the printing ink to a slurry tank of a light-curing 3D printer, performs DLP 3D printing according to the 3D bracket model, and obtains a printed ceramic bracket.

[0043] In the present invention, the DLP 3D printing parameter settings are preferably: when printing the support body, the layer thickness of the scraper is 75-200 μm; the single layer thickness is 25-50 μm; the illumination time is 3.5-9S; the illumination intensity is 6-9 mW / cm 2 The present invention sets the parameters of DLP 3D printing within the above range to ensure that the ceramic bracket can be completely formed and attached to the forming table.

[0044] In the present invention, the 3D support model is preferably one of a 6*6 90° grid model, a 6*6 45° grid model, and a 6*6 round hole honeycomb briquette model.

[0045] In the present invention, the method for making the 6*6 90° grid model preferably includes: creating a rectangular parallelepiped model with a width of 0.4-0.5 mm, a height of 0.2-0.3 mm, and a length of 8 mm in the MaterialiseMagics23.0 software, and placing the above 6 rectangular parallelepipeds with the same length, width and height in parallel along the x-axis on the xy plane with a spacing of 0.45-0.6 mm to form a complete grid model, copying 10 of the grids along the z-axis direction of the prepared grid model, and each grid differs by 90° from the previous layer on the xy plane to obtain a preliminary model, and finally creating a cylinder with a height of 6 mm and a diameter of 6 mm, aligning the cylinder with the center point of the model, and using Boolean operations to obtain the 6*6 90° grid model.

[0046] In the present invention, the 6*6 45° grid model making method preferably includes: creating a rectangular parallelepiped model with a width of 0.4-0.5mm, a height of 0.2-0.3mm, and a length of 8mm in MaterialiseMagics23.0 software, and placing the above 6 rectangular parallelepipeds with the same length, width and height in parallel along the x-axis on the xy plane with a spacing of 0.45-0.6mm to form a complete grid model, copying the prepared grid model along the z-axis direction 4 of the grids, and each grid differs from the previous layer at an angle of 45° on the xy plane to obtain a model, copying the model 4 times along the z-axis to obtain a preliminary model of the 45° grid model, and finally creating a cylinder with a height of 6mm and a diameter of 6mm, aligning the cylinder with the center point of the model, and using a Boolean intersection operation to obtain the 6*6 45° grid model.

[0047] In the present invention, the method for making the 6*6 round-hole honeycomb briquettes model preferably includes: creating a cylinder with a diameter of 0.8-1 mm in the MaterialiseMagics23.0 software, and arranging 25 of the cylinders perpendicular to the xy plane at a spacing of 0.4-0.6 mm to form a cylinder array, copying 2 arrays, and rotating 90° along the x-axis and y-axis respectively, then removing the cylinders at the 4 vertex corners of the array perpendicular to the xy plane and the adjacent cylinders to obtain a preliminary model, then creating a cylinder with a height of 6 mm and a diameter of 6 mm, and aligning the cylinder with the center point of the model to obtain the 6*6 round-hole honeycomb briquettes model using a Boolean subtraction operation.

[0048] According to the required 3D bracket model, the present invention exports the STL file of the corresponding 3D bracket model established in the MaterialiseMagics23.0 software into the 10dim software, converts the STL file into a TDP file and imports it into the printer, and sets the corresponding 3D printing parameters to perform 3D printing.

[0049] After obtaining the printed ceramic scaffold, the present invention sequentially cleans, dries and sinters the printed ceramic scaffold to obtain a bioceramic scaffold.

[0050] In the present invention, the cleaning preferably includes washing with anhydrous ethanol for 2 to 4 times and washing with water for 2 to 4 times in sequence. The present invention removes excess printing ink attached to the ceramic support by cleaning, ensuring that the pores of the ceramic support are not blocked by the printing ink.

[0051] In the present invention, the drying temperature is preferably 50-70°C, and the drying time is preferably 22-26 hours. The present invention removes the residual solvent by drying, dries the residual water and anhydrous ethanol on the surface of the ceramic stent, and ensures that the final ceramic stent does not contain other impurities.

[0052] In the present invention, the sintering preferably includes: heating the dried ceramic scaffold to 400-600°C at a rate of 2-5°C / min, keeping it warm for 10-14 hours, then heating it to 1200-1330°C at a rate of 1-3°C / min, keeping it warm for 20-28 hours, then cooling it to 90-110°C at a rate of 8-12°C / min, and finally cooling it with the furnace to obtain a bioceramic scaffold. More preferably, the dried ceramic scaffold is heated to 500°C at a rate of 4°C / min, keeping it warm for 12 hours, then heating it to 1280-1320°C at a rate of 2°C / min, keeping it warm for 24 hours, then cooling it to 100°C at a rate of 10°C / min, and finally cooling it with the furnace to obtain a bioceramic scaffold.

[0053] The controlled sintering of the present invention is carried out in a staged-programmed heating manner, and the sintering stages, heating rate, insulation temperature and time are controlled within the above ranges, wherein the first stage of heating is to completely vaporize the bio-based ceramic resin, and the second stage of heating is to heat the magnesia feldspar to a molten state to make its microstructure more tightly bonded, thereby significantly improving the mechanical properties and porosity of the prepared bioceramic scaffold, so as to significantly improve the fracture toughness and brittleness of the bioceramic scaffold, avoid sudden fracture of the bioceramic scaffold when subjected to impact or excessive load, increase its mechanical load, and obtain a bioceramic scaffold with a complete structure and excellent comprehensive performance.

[0054] The present invention also provides a bioceramic scaffold prepared by the preparation method described in the above technical solution. In the present invention, the bioceramic scaffold comprises magnesia chalcedony.

[0055] In the present invention, the bioactive ions contained in the bioceramic scaffold are preferably one or more of calcium ions, magnesium ions and silicon ions; the silicon ions are preferably metasilicate ions SiO3 2- Or orthosilicate ion SiO4 4- One or more of the .

[0056] The present invention also provides a bioceramic scaffold for use in bone repair, wherein the bioceramic scaffold is a bioceramic scaffold prepared by the preparation method described in the above technical solution or a bioceramic scaffold described in the above technical solution.

[0057] The present invention uses DLP light-curing 3D printing technology to design a bioceramic scaffold for improving bone tissue repair using magnesia feldspar, which has a compressive strength similar to that of human bones and a moderate degradation rate, and the mechanical strength, porosity and scaffold structure meet the requirements of bone repair scaffolds. The present invention uses DLP 3D printing technology to prepare a new porous bioceramic scaffold, explores the effects of scaffold morphology, solid content, and sintering parameters on the mechanical properties of bone repair scaffolds, and finally prepares a bioceramic scaffold with high mechanical properties and excellent bone repair effect.

[0058] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0059] The bio-based photosensitive resin used in the embodiment of the present invention is derived from the Yisheng bio-based LCD water-washable resin PW100 photosensitive resin.

[0060] Example 1

[0061] A method for preparing a bioceramic scaffold, comprising the following steps:

[0062] (1) 19.6 g of magnesia chalcitrino powder with an average particle size of 10 μm and 10 mL of a bio-based photosensitive resin were mixed in an agate ball mill, and the mixture was ball milled at a speed of 500 rpm for 6 h to obtain a printing ink having a magnesia chalcitrino mass percentage (solid phase ratio) of 40%;

[0063] The preparation method of the magnesia chalcedony powder is as follows: 2 mol / L nitric acid is added to 150 mL of deionized water, the pH value is adjusted to 1.5, then 44.6 mL of TEOS is added dropwise, a hydrolysis reaction is carried out for 1 hour until the solution is clear and transparent, and then weighed magnesium nitrate hexahydrate and calcium nitrate tetrahydrate are added, and stirring is continued for 6 hours to obtain a mixture; the mixture is sealed at 60° C. for 24 hours, then unsealed for 1 hour, dried at 120° C., then ground and calcined at 1200° C. for 3 hours, and then ball milled and sieved in sequence to obtain magnesia chalcedony powder;

[0064] (2) The printing ink obtained in step (1) is transferred to the slurry tank of the light-curing printer, and the STL file of the 6*6 90° grid model established in the MaterialiseMagics23.0 software is exported into the 10dim software, and the STL file is converted into TDP, and the file is imported into the printer, and the corresponding 3D printing parameters are set to perform 3D printing to obtain a printed ceramic bracket;

[0065] The method for making the 6*6 90° grid model comprises: creating a rectangular parallelepiped model with a width of 0.4-0.5 mm, a height of 0.2-0.3 mm, and a length of 8 mm in MaterialiseMagics23.0 software, and placing the above 6 rectangular parallelepipeds with the same length, width, and height in parallel along the x-axis on the xy plane at a spacing of 0.45-0.6 mm to form a complete grid model, copying the prepared grid model by 10 of the grids along the z-axis, and each grid differs from the previous layer in the xy plane by 90° to obtain a preliminary model, and finally creating a cylinder with a height of 6 mm and a diameter of 6 mm, aligning the cylinder with the center point of the model, and using Boolean operation to obtain the 6*6 90° grid model;

[0066] The parameters of the DLP 3D printing are as follows: when printing the support body, the layer thickness of the scraper is selected to be 200 microns; the single layer thickness is 50 microns; the illumination time is 7.5S; the DLP 3D printing is performed under the illumination condition of the illumination intensity of 6mW / cm2;

[0067] (3) The printed ceramic scaffold obtained in step (2) is washed with anhydrous ethanol and deionized water, and then dried in a 60°C oven for 24 hours; the dried ceramic scaffold is placed in a sintering furnace and heated to 500°C at a heating rate of 4°C / min and kept warm for 12 hours, then heated to 1300°C at a heating rate of 2°C / min and kept warm for 24 hours, then quickly cooled to 100°C at a rate of 10°C / min, and finally cooled in the furnace to obtain a bioceramic scaffold.

[0068] Example 2

[0069] A bioceramic scaffold is prepared according to the method of Example 1, which is different from Example 1 in that: the 3D scaffold model in step (2) is replaced by a 6*6 45° grid model, and the method for making the 6*6 45° grid model comprises: creating a rectangular parallelepiped model with a width of 0.4-0.5 mm, a height of 0.2-0.3 mm, and a length of 8 mm in MaterialiseMagics23.0 software, and placing the above 6 rectangular parallelepipeds with the same length, width, and height in parallel along the x-axis on the xy plane at a spacing of 0.45-0.6 mm to form a complete grid model, copying the prepared grid model by 4 of the grids along the z-axis direction, and each grid differs from the previous layer by 45° on the xy plane to obtain a model, copying the model by 4 along the z-axis to obtain a preliminary model of the 45° grid model, and finally creating a cylinder with a height of 6 mm and a diameter of 6 mm, aligning the cylinder with the center point of the model, and then using a Boolean intersection operation to obtain the 6*6 45° grid model;

[0070] The DLP 3D printing parameter settings are as follows: when printing the support body, the layer thickness of the scraper is selected to be 200 microns; the single layer thickness is 50 microns; the illumination time is 3.5S; the illumination intensity is 7.5mW / cm 2 The bracket is printed under the lighting conditions of

[0071] Example 3

[0072] A bioceramic scaffold is prepared according to the method of Example 1, which is different from Example 1 in that: the 3D scaffold model in step (2) is replaced with a 6*6 round hole honeycomb briquettes model, and the method for making the 6*6 round hole honeycomb briquettes model comprises: creating a cylinder with a diameter of 0.8-1 mm in MaterialiseMagics23.0 software, and arranging 25 of the cylinders perpendicular to the xy plane at a spacing of 0.4-0.6 mm to form a cylinder array, copying 2 of the arrays, and rotating them 90° along the x-axis and y-axis respectively, then removing the cylinders at the four vertex angles of the array perpendicular to the xy plane and the adjacent cylinders to obtain a preliminary model, then creating a cylinder with a height of 6 mm and a diameter of 6 mm, aligning the cylinder with the center point of the model, and using Boolean subtraction operation to obtain the 6*6 round hole honeycomb briquettes model;

[0073] The DLP 3D printing parameter settings are as follows: when printing the support body, the layer thickness of the scraper is selected to be 200 microns; the single layer thickness is 50 microns; the illumination time is 9S; the illumination intensity is 9mW / cm 2 The bracket is printed under the lighting conditions of

[0074] Example 4

[0075] The bioceramic scaffold was prepared according to the method of Example 1, except that the solid ratio of the printing ink in step (1) was 45%.

[0076] Example 5

[0077] The bioceramic scaffold was prepared according to the method of Example 2, except that the solid ratio of the printing ink in step (1) was 45%.

[0078] Example 6

[0079] The bioceramic scaffold was prepared according to the method of Example 3, except that the solid ratio of the printing ink in step (1) was 45%.

[0080] Example 7

[0081] The bioceramic scaffold was prepared according to the method of Example 1, except that the solid ratio of the printing ink in step (1) was 50%.

[0082] Example 8

[0083] The bioceramic scaffold was prepared according to the method of Example 2, except that the solid ratio of the printing ink in step (1) was 50%.

[0084] Example 9

[0085] The bioceramic scaffold was prepared according to the method of Example 3, except that the solid ratio of the printing ink in step (1) was 50%.

[0086] Example 10

[0087] The bioceramic scaffold was prepared according to the method of Example 1, except that the solid ratio of the printing ink in step (1) was 55%.

[0088] Embodiment 11

[0089] The bioceramic scaffold was prepared according to the method of Example 2, except that the solid ratio of the printing ink in step (1) was 55%.

[0090] Example 12

[0091] The bioceramic scaffold was prepared according to the method of Example 3, except that the solid ratio of the printing ink in step (1) was 55%.

[0092] Embodiment 13

[0093] A bioceramic scaffold was prepared according to the method of Example 11, except that: in step (3), the dried ceramic scaffold was placed in a sintering furnace and heated to 500°C at a heating rate of 4°C / min and kept warm for 12 hours, then heated to 1200°C at a heating rate of 2°C / min and kept warm for 24 hours, then quickly cooled to 100°C at a rate of 10°C / min, and finally cooled in the furnace to obtain a bioceramic scaffold.

[0094] Embodiment 14

[0095] A bioceramic scaffold is prepared according to the method of Example 13, except that: in step (3), the dried ceramic scaffold is placed in a sintering furnace and heated to 500°C at a heating rate of 4°C / min and kept warm for 12 hours, then heated to 1250°C at a heating rate of 2°C / min and kept warm for 24 hours, then quickly cooled to 100°C at a rate of 10°C / min, and finally cooled in the furnace to obtain a bioceramic scaffold.

[0096] Comparative Example 1

[0097] A bioceramic scaffold is prepared according to the method of Example 14, except that: in step (3), the dried ceramic scaffold is placed in a sintering furnace and heated to 500°C at a heating rate of 4°C / min and kept warm for 12 hours, then heated to 1350°C at a heating rate of 2°C / min and kept warm for 24 hours, then quickly cooled to 100°C at a rate of 10°C / min, and finally cooled in the furnace to obtain a bioceramic scaffold.

[0098] Figure 1 The physical image and XRD diagram of the magnesia chalcite powder prepared by the sol-gel method in Example 1 of the present invention are shown in FIG. Figure 1 (a) is the actual picture. Figure 1 (b) is the XRD pattern. Figure 1 It can be seen that the white powder prepared by the sol-gel method is magnesia chalcedony, and the prepared magnesia chalcedony powder does not contain other impurities.

[0099] Figure 2 The actual pictures of the bioceramic scaffolds prepared in Examples 1, 2 and 3 of the present invention are shown in FIG. Figure 2 (a) above is a top view of the 90° grid bioceramic scaffold prepared in Example 1, and (a) below is a side view of the 90° grid bioceramic scaffold prepared in Example 1. Figure 2 (b) in the middle is a top view of the 45° grid bioceramic scaffold prepared in Example 2, and (b) in the bottom is a side view of the 45° grid bioceramic scaffold prepared in Example 2. Figure 2 (c) is a top view of the round-hole bioceramic scaffold prepared in Example 3, and (c) is a side view of the round-hole bioceramic scaffold prepared in Example 3. Figure 2 It can be seen that compared with the grid-shaped ceramic bracket, the overall integrity of the round hole bracket after molding is worse and slight deformation occurs.

[0100] 1. Experiment on the influence of different geometric shapes (models) on the mechanical strength of products

[0101] The prepared bioceramic scaffolds were placed on a universal testing machine and a 200N round head was used to compress the ceramic scaffolds at a speed of 1 mm / min in a direction perpendicular to the xy coordinate axis and parallel to the z axis to obtain the compressive strength statistical graphs of the bioceramic scaffolds prepared in Examples 1, 2, and 3 with different geometric shapes. Figure 3 As shown, 90°, 45° and round hole represent the 6*6 90° grid model, 6*6 45° grid model and 6*6 round hole honeycomb briquette model respectively. Figure 3 It can be seen that the bioceramic scaffold with a 90° grid model has the lowest compressive strength, followed by the scaffold with a round hole honeycomb briquettes shape, and the 6*6 45° grid model has the highest compressive strength.

[0102] 2. Experiment on the influence of different sintering curves on the mechanical strength of products

[0103] In Examples 13, 14, 11 of the present invention and Comparative Example 1, the dried ceramic scaffolds were sintered at 1200° C., 1250° C., 1300° C., and 1350° C., respectively. The corresponding bioceramic scaffolds were placed on a universal testing machine and a 200N round head was used to compress the bioceramic scaffolds at a speed of 1 mm / min in a direction perpendicular to the xy coordinate axis and parallel to the z axis to test the compressive strength of the bioceramic scaffolds. The mechanical strength statistical graphs of the bioceramic scaffolds prepared in Examples 13, 14, 11 and Comparative Example 1 with different sintering curves are shown in FIG. Figure 4 As shown, the actual picture of the bioceramic scaffold prepared in Comparative Example 1 is as follows Figure 5 As shown. Figure 4 It can be seen that the compressive strength of the bioceramic scaffold prepared at a sintering temperature of 1300℃ is the highest, and that at 1200℃ is the lowest. The ceramic scaffold sintered at 1350℃ has melted due to the high sintering temperature. Figure 5 As shown in the figure, the bioceramic scaffold prepared at a sintering temperature of 1300°C has the highest mechanical properties.

[0104] 3. Experiment on the influence of different solid ratios on the mechanical strength of products

[0105] The bioceramic scaffolds prepared in Examples 2, 5, 8, and 11 were placed on a universal testing machine and a 200N round head was used to compress the ceramic scaffolds at a speed of 1 mm / min in a direction perpendicular to the xy coordinate axis and parallel to the z axis to obtain a statistical graph of the compressive strength of the bioceramic scaffolds prepared in Examples 2, 5, 8, and 11 with different solid phase ratios. Figure 6 As shown, 40, 45, 50 and 55 represent 40%, 45%, 50% and 55% of the solid phase, respectively. Figure 6 It can be seen that the higher the solid content, the higher the compressive strength of the bioceramic scaffold. However, when the solid content is lower than 45%, the compressive strength of the ceramic scaffold is lower than the compressive strength of human cancellous bone (6-10 MPa), so it does not have the potential to be used as a bone repair material.

[0106] In summary, the present invention adopts a printing ink with a certain solid-to-carbon ratio and utilizes photocuring 3D printing technology to prepare a printed ceramic scaffold with a certain three-dimensional topological structure, and then selects a reasonable high-temperature sintering curve to finally prepare a bioceramic scaffold with high mechanical strength and porosity, which significantly improves its bone repair effect.

[0107] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a bioceramic scaffold, characterized in that: The following steps are involved: (1) mixing magnesia chalcedony powder and bio-based photosensitive resin, and then ball milling to obtain printing ink; (2) The printing ink obtained in step (2) is transferred to the slurry tank of the light-curing 3D printer, and DLP 3D printing is performed according to the 3D bracket model to obtain a printed ceramic bracket. (3) The printed ceramic scaffold obtained in step (2) is cleaned, dried and sintered in sequence to obtain a bioceramic scaffold.

2. The preparation method according to claim 1, characterized in that: The particle size of the magnesia quartz powder in the step (1) is 4 to 20 μm.

3. The preparation method according to claim 1, characterized in that: The rotation speed of the ball mill in the step (1) is 500-600 rpm, and the time of the ball mill is 4-6 hours.

4. The preparation method according to claim 1, characterized in that: The mass percentage of magnesia quartz powder in the printing ink in step (1) is 40% to 60%.

5. The preparation method according to claim 1, characterized in that: The parameters of DLP 3D printing in step (2) are as follows: when printing the support body, the layer thickness of the scraper is 75-200 μm; the single layer thickness is 25-50 μm; the illumination time is 3.5-9 s; the illumination intensity is 6-9 mW / cm 2 .

6. The preparation method according to claim 1, characterized in that: In the step (2), the 3D support model is one of a 6*6 90° grid model, a 6*6 45° grid model, and a 6*6 round hole honeycomb briquette model; The method for making the 6*6 90° grid model comprises: creating a rectangular parallelepiped model with a width of 0.4-0.5 mm, a height of 0.2-0.3 mm, and a length of 8 mm in MaterialiseMagics23.0 software, and placing the above 6 rectangular parallelepipeds with the same length, width, and height in parallel along the x-axis on the xy plane at a spacing of 0.45-0.6 mm to form a complete grid model, copying the prepared grid model by 10 of the grids along the z-axis, and each grid differs from the previous layer in the xy plane by 90° to obtain a preliminary model, and finally creating a cylinder with a height of 6 mm and a diameter of 6 mm, aligning the cylinder with the center point of the model, and using Boolean operation to obtain the 6*6 90° grid model; The method for making a 6*6 45° grid model comprises: creating a rectangular parallelepiped model with a width of 0.4-0.5 mm, a height of 0.2-0.3 mm, and a length of 8 mm in MaterialiseMagics23.0 software, and placing the above 6 rectangular parallelepipeds with the same length, width, and height in parallel along the x-axis on the xy plane at a spacing of 0.45-0.6 mm to form a complete grid model, copying the prepared grid model by 4 of the grids along the z-axis direction, and each grid differs from the previous layer in an angle of 45° on the xy plane to obtain a model, copying the model 4 times along the z-axis to obtain a preliminary model of a 45° grid model, and finally creating a cylinder with a height of 6 mm and a diameter of 6 mm, aligning the cylinder with the center point of the model, and using a Boolean intersection operation to obtain the 6*6 45° grid model; The method for making the 6*6 round-hole honeycomb briquettes model comprises: creating a cylinder with a diameter of 0.8-1 mm in MaterialiseMagics23.0 software, and arranging 25 of the cylinders perpendicular to the xy plane at a spacing of 0.4-0.6 mm to form a cylinder array, copying 2 arrays, and rotating 90° along the x-axis and y-axis respectively, then removing the cylinders at the 4 vertex angles of the array perpendicular to the xy plane and the adjacent cylinders to obtain a preliminary model, then creating a cylinder with a height of 6 mm and a diameter of 6 mm, aligning the cylinder with the center point of the model, and using Boolean subtraction operation to obtain the 6*6 round-hole honeycomb briquettes model.

7. The preparation method according to claim 1, characterized in that: The drying temperature in step (3) is 50-70° C., and the drying time is 22-26 hours.

8. The preparation method according to claim 1, characterized in that: The sintering in step (3) includes: heating the dried ceramic scaffold to 400-600°C at a rate of 2-5°C / min and then keeping the temperature for 10-14 hours, then heating it to 1200-1330°C at a rate of 1-3°C / min and then keeping the temperature for 20-28 hours, then cooling it to 90-110°C at a rate of 8-12°C / min, and finally cooling it in the furnace to obtain a bioceramic scaffold.

9. A bioceramic scaffold prepared by the preparation method according to any one of claims 1 to 8.

10. A bioceramic scaffold for use in bone repair, characterized in that: The bioceramic scaffold is a bioceramic scaffold prepared by the preparation method according to any one of claims 1 to 8 or a bioceramic scaffold according to claim 9.

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