Porous artificial bone and preparation method thereof

Abstract

The invention belongs to the field of medical materials. The invention provides a porous artificial bone and a preparation method thereof, the components of the porous artificial bone comprise absorbable macromolecules and an orthopedic inorganic implant material, the mass ratio of the absorbable macromolecules to the orthopedic inorganic implant material is 1: 0.1-2, the porous artificial bone has a through porous structure, the porosity is greater than 70%, and the pore size distribution range is less than 500 [mu] m. The porous artificial bone has a pore structure and mechanical properties beneficial to bone regeneration, the pore diameter is stable, the mechanical properties are appropriate, after the porous artificial bone is implanted into a defect part, the bone volume is always increased, the increase rate of regenerated bone tissue is remarkably improved, the effect of bone conduction is effectively achieved, bone regeneration is very beneficial, and animal experiments prove that the porous artificial bone has a good application prospect. The material can be used for filling and repairing various bone defects in orthopedic surgery. The preparation method is simple, stable and effective, can be absorbed, is low in cost, has great market potential, and is simple, stable and effective compared with a conventional artificial bone preparation method at present.

Description

Technical Field

[0001] The invention belongs to the field of medical materials, and in particular relates to a porous artificial bone and a preparation method thereof. Background Art

[0002] Bone defects are mostly caused by severe trauma, inflammation, bone tumor resection, etc., and their incidence rate remains high. Small-scale bone defects can often be healed by the body on its own. If the bone defect exceeds a certain range (usually 2 cm), it exceeds the maximum self-repair ability of the bone, and the bone defect site cannot heal on its own, resulting in the formation of discontinuous callus, causing bone nonunion, and then leading to damage to the bone structure and function, affecting the patient's life. At present, in orthopedic surgery, bone defects are mostly filled with bone implants. The filling material provides biomechanical support for the defect site and participates in bone regeneration. In addition to having good biocompatibility, osteoconduction, osteoinduction and osteogenesis properties, ideal bone implants also need to have suitable mechanical properties, be easy to operate, and provide certain mechanical support after implantation into the human body.

[0003] Among bone implants, autologous bone is the most ideal graft, but the quantity is limited and it will cause damage to the bone harvesting site. Allogeneic bone has the same properties as autologous bone, such as bone formation, osteoinduction and osteoconduction, but there are risks of immunogenicity and infectious diseases. The use of synthetic materials for bone repair can not only solve many problems existing in autologous bone and allogeneic bone, but also obtain excellent substitutes through material and structural design. Synthetic bone repair materials will be the development direction of bone grafts in the future.

[0004] Materials for tissue repair, especially bone tissue repair, require a porous structure. It is generally believed that a pore size greater than 200 μm is conducive to bone regeneration. Commonly used methods for forming porous organic / inorganic composite materials include electrospinning, freeze drying, and the addition of porogens. Electrospinning is mainly used to prepare membrane materials, and block materials can also be prepared, but fiber-based materials always have the problem of too low compressive strength, and cannot provide mechanical support after filling the defect. For freeze-drying technology, the solvent is changed from liquid to solid and finally to gas by cooling and volatilizing. The position originally occupied by the solvent is retained to form a pore structure, but the pore structure prepared by single freeze drying is generally microporous. The addition of porogens can stably and controllably obtain porous materials with the required pore size.

[0005] Therefore, in view of bone defects caused by various reasons such as surgery, inflammation, cysts or trauma, as well as the problems existing in the current artificial bone preparation methods, the present invention aims to provide an artificial bone with a pore structure and stable mechanical properties that improves bone regeneration ability, and a simple, stable and effective preparation method. Summary of the invention

[0006] In order to solve the problems existing in the prior art, the present invention provides a porous artificial bone and a preparation method thereof. The porous artificial bone has a pore structure and mechanical properties that are conducive to bone regeneration, a stable pore size and suitable mechanical properties, and is used for filling and repairing various bone defects including those in orthopedic surgery. After implantation into the defect site, the bone volume is always increasing, and the rate of increase of regenerated bone tissue is significantly improved, which effectively plays a role of bone conduction and is very beneficial to bone regeneration, and has been verified by animal experiments.

[0007] The purpose of the present invention is to provide a porous artificial bone, whose components include absorbable polymers and orthopedic inorganic implant materials; the mass ratio of the absorbable polymers to the orthopedic inorganic implant materials is 1:0.1-2, and the porous artificial bone has a through porous structure, a porosity greater than 70%, and a pore size distribution range less than 500μm.

[0008] The porous artificial bone of the present invention has a pore size of less than 500 μm, mainly distributed in 200-500 μm, a porous structure with high porosity and interconnection, and suitable compressive strength of 2-100 MPa. The porous artificial bone of the present invention has a significant bone regeneration effect. After implantation into the defect site, the bone volume is always increasing, the rate of increase of regenerated bone tissue is significantly improved, mechanical support can be provided in the early stage of implantation, bone formation space can be maintained, and bone tissue reconstruction can be participated in the later stage.

[0009] The present invention also aims to provide a method for preparing the porous artificial bone, comprising the following steps:

[0010] (1) weighing an absorbable polymer, an orthopedic inorganic implant material, a porogen, and a good solvent according to a ratio, dissolving the absorbable polymer in the good solvent to obtain an absorbable polymer solution, adding the orthopedic inorganic implant material and the porogen to the absorbable polymer solution, and mixing them uniformly to obtain a plastic mixture;

[0011] (2) pouring the plastic mixture obtained in step (1) into a mold, drying and solidifying it into a mold;

[0012] (3) The mixture solidified and formed in step (2) is treated to remove the porogen and dried to obtain a porous artificial bone.

[0013] The preparation method of the present invention obtains a plastic mixture with suitable viscosity, which is convenient for molding on the one hand, and is also for the inorganic particles to be stably maintained in the synthetic polymer matrix to ensure the uniformity of the composition of the mixture. The porous artificial bone prepared by the preparation method has uniform pore size distribution and stable mechanical properties, which enhances the bone conduction effect and significantly improves the bone regeneration rate.

[0014] Preferably, the plastic mixture in step (1) is a plastic mass-like mixture, and the preparation method thereof comprises one of the following:

[0015] Method 1: Prepare an absorbable polymer solution with a concentration of 5-10wt%, add an orthopedic inorganic implant material and a porogen, mix well, and continue stirring to evaporate the solvent until the concentration of the absorbable polymer solution is not less than 20wt%, to obtain a plastic mass-like mixture;

[0016] Method 2: Prepare an absorbable polymer solution with a concentration of not less than 20 wt%, add an orthopedic inorganic implant material and a porogen, mix well, and obtain a plastic mass-like mixture;

[0017] Method 3: Prepare an absorbable polymer solution with a concentration of 5-10wt%, add orthopedic inorganic implant materials and porogens, mix well to obtain a suspension, pour the suspension into a poor solvent for the absorbable polymer, and the mixture precipitates and settles to obtain a plastic mass-like mixture.

[0018] The mixture of absorbable polymer solution or the mixture precipitated from the suspension with a concentration of not less than 20 wt% obtained by the above method has enhanced viscosity and becomes a plastic mass-like mixture.

[0019] In method 2, the concentration set when preparing the polymer solution is too high, the dissolution process of the polymer is extremely slow, or the polymer cannot be completely dissolved. In this case, the polymer can be completely dissolved by reducing the size of the polymer to be dissolved or heating.

[0020] Preferably, the drying method in step (2) is freeze drying, static drying at room temperature, or forced air drying at a temperature below the boiling point of the solvent. The drying time is 1 day to 5 days.

[0021] The present invention also aims to provide another method for preparing the porous artificial bone, comprising the following steps:

[0022] (1) weighing an absorbable polymer, an orthopedic inorganic implant material, a porogen, and a good solvent according to a ratio, dissolving the absorbable polymer in the good solvent to obtain an absorbable polymer solution, adding the orthopedic inorganic implant material and the porogen to the absorbable polymer solution, and mixing them uniformly to obtain a suspension;

[0023] (2) pouring the suspension obtained in step (1) into a mold and rapidly freezing and freeze-drying the mixture;

[0024] (3) The mixture obtained by freeze-drying in step (2) is treated to remove the porogen and dried to obtain a porous artificial bone.

[0025] Furthermore, the rapid freezing in step (2) includes freezing with liquid nitrogen, or precooling the freeze dryer to a set temperature, and then quickly pouring the suspension into a mold in the freeze dryer cabinet. Rapid freezing is performed to prevent the inorganic matter therein from settling.

[0026] In the present invention, the absorbable polymer is an absorbable polyester, the absorbable polyester includes at least one of polylactic acid and lactide-glycolide copolymer, and the orthopedic inorganic implant material includes at least one of calcium phosphate, hydroxyapatite, β-tricalcium phosphate, and bioactive glass.

[0027] The number average molecular weight of absorbable polyester is 100,000-300,000.

[0028] Preferably, a good solvent that dissolves absorbable polymers is preferably a solvent with relatively strong solubility and volatility, such as dichloromethane, acetone, and the like.

[0029] Preferably, the porogen is sodium chloride or ammonium bicarbonate. The amount of the porogen is 1-20 times the total mass of the absorbable polymer and the orthopedic inorganic implant material. The porogen is sodium chloride or ammonium bicarbonate. It can be simply removed by washing with water.

[0030] The method of removing the porogen is to wash with pure water, and the water can be changed regularly or the mixture can be placed in flowing water. The treatment time is 2-5 days. The drying method after removing the porogen is vacuum drying, the drying temperature is 30-40℃, and the drying time is 18-48h.

[0031] The present invention also aims to provide a method for using porous artificial bone, comprising the steps of cleaning the bone defect, trimming the porous artificial bone according to the size and shape of the bone defect, then filling the bone defect with the porous artificial bone, and finally suturing.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] (1) The porous artificial bone of the present invention has a high porosity (greater than 70%) and a continuous porous structure, that is, it has osteoconductivity. The high porosity is conducive to the transfer of small molecule nutrients and the excretion of metabolic products, and the continuous pore structure is conducive to cell migration, angiogenesis and bone integration.

[0034] (2) The porous artificial bone of the present invention has suitable mechanical properties. The synthetic polymer provides toughness and the inorganic substance provides strength, so that the artificial bone has mechanical characteristics similar to those of natural bone and is strong but not brittle.

[0035] (3) The porous artificial bone of the present invention has a degradation rate that matches bone regeneration. The absorbable synthetic polymer degrades quickly, providing more space for bone tissue to grow into. However, the presence of inorganic substances such as hydroxyapatite is beneficial to maintaining the stability of the bone regeneration space, which is beneficial to the formation of new bone and the remodeling of bone tissue. The repair process of rabbit femoral condyle bone defects was tested, and the bone tissue accounted for more than 40% after 12 months.

[0036] (4) The porous artificial bone of the present invention is easy to trim and can be used for various defects and wounds;

[0037] (5) The method for preparing porous artificial bone of the present invention can stably and controllably obtain artificial bone with the desired pore size, and the process is simple and can be easily industrialized. In addition, it does not require special equipment such as high temperature and high pressure, and is safe and low-cost.

[0038] In summary, the porous artificial bone of the present invention has a stable pore size, high porosity, a continuous porous structure, and suitable mechanical properties. After being implanted in the defect site, it significantly enhances the effect of bone conduction, is very beneficial to bone regeneration, and can be used for filling and repairing various bone defects including orthopedic surgery. Its preparation method is simple, stable and effective, and it is absorbable and low in cost, with great market potential. Compared with the current conventional preparation method of artificial bone, it is simple, stable and effective. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 The cylindrical artificial bone prepared in Example 1;

[0040] Figure 2 This is a microscopic image of the artificial bone prepared in Example 1;

[0041] Figure 3 The porosity and compressive strength test results of the artificial bones prepared in Examples 1-4; DETAILED DESCRIPTION

[0042] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0043] The present invention provides an artificial bone for filling and repairing various bone defects in orthopedic surgery. The artificial bone is composed of absorbable synthetic polymers and inorganic substances. The synthetic polymer material can be a known absorbable polyester material or any combination thereof, such as polylactic acid (PLA), lactide-co-glycolide copolymer (PLGA), etc. The inorganic substance is calcium phosphate (hydroxyapatite, β-tricalcium phosphate), bioactive glass and other commonly used inorganic implant materials in orthopedics or any combination thereof.

[0044] The artificial bone is in block shape, specifically, cylindrical or square shape.

[0045] The artificial bone has a through porous structure, the porosity is greater than 70%, and the pore size is mainly distributed in the range of 200-500 μm. The compressive strength of the artificial bone is 2-100 MPa.

[0046] The invention provides a method for preparing an artificial bone, which specifically comprises preparing a synthetic polymer solution, adding an inorganic substance and a porogen to obtain a uniform mixture, pouring the mixture into a mold for molding, drying, and finally removing the porogen to obtain the artificial bone.

[0047] In the above-mentioned method for preparing artificial bone, the solvent used to dissolve the polymer is preferably a solvent with relatively strong solubility and volatility, such as dichloromethane, acetone, etc.

[0048] In the above-mentioned method for preparing artificial bone, the amount of inorganic substance added is 10-60%, and the amount of porogen added is 1-20 times the total mass of the polymer and the inorganic substance.

[0049] In the above-mentioned method for preparing artificial bone, the porogen used is sodium chloride or ammonium bicarbonate, which can be simply removed by washing with water.

[0050] In the above-mentioned preparation method of artificial bone, the key is to obtain a mixture with suitable viscosity, which is convenient for molding on the one hand, and on the other hand, it is to ensure that the inorganic particles can be stably maintained in the synthetic polymer matrix to ensure the uniformity of the composition of the mixture. The mixture can be obtained by any of the following methods:

[0051] Method 1: Add inorganic substances and porogens to a synthetic polymer solution with a concentration of 5-10wt%, stir evenly, open the container, and continue stirring to evaporate excess solvent until the polymer concentration is not less than 20%, the viscosity of the mixed material is enhanced, and it becomes a plastic mass-like mixture.

[0052] Method 2: Prepare a high concentration (concentration>20wt%) synthetic polymer solution, add inorganic substances and porogens, stir evenly, and obtain a dough-like mixture. In this method, the concentration set when preparing the polymer solution is too high, the dissolution process of the polymer is extremely slow, or the polymer cannot be completely dissolved. In this case, the polymer can be completely dissolved by reducing the size of the polymer to be dissolved or heating.

[0053] Method 3: Add inorganic matter and porogen to a synthetic polymer solution with a concentration of 5-10wt%, stir evenly to obtain a suspension, and then pour the suspension into ethanol or other poor solvents for the synthetic polymer used to precipitate and precipitate the mixture to obtain a plastic agglomerate mixture.

[0054] In the above-mentioned method for preparing artificial bone, the mixture is dried by freeze drying, static drying at room temperature, or forced air drying at a temperature below the boiling point of the solvent. The drying time is 1 day to 5 days.

[0055] In the above-mentioned preparation method of artificial bone, in addition to trying to obtain a mixture with suitable viscosity, a polymer / inorganic substance / porogen suspension can also be directly prepared, and the suspension is poured into a mold and then quickly frozen to prevent the inorganic substance therein from settling. The rapid freezing method includes liquid nitrogen freezing, or precooling the freeze dryer to a set temperature, and then quickly pouring the suspension into the mold in the freeze dryer box, followed by freeze drying, and finally removing the porogen and drying to obtain the artificial bone.

[0056] In the above-mentioned preparation method of artificial bone, the method of removing the porogen is to wash with pure water, and the water can be changed regularly or the mixture can be placed in flowing water. The treatment time is 2d-5d.

[0057] In the above-mentioned preparation method of artificial bone, the drying method after removing the porogen is vacuum drying, the drying temperature is 30-40° C., and the drying time is 18-48 hours.

[0058] The method of using the artificial bone is as follows: selecting artificial bones of appropriate specifications according to actual needs; cleaning the wound to fully expose the defect area; opening the package, slightly trimming the artificial bone according to the defect size and shape, and then filling it into the bone defect area to ensure that the bone defect area is effectively filled; and finally suturing.

[0059] Example 1 Preparation of porous artificial bone

[0060] 1. Construction of the mixed system: Dissolve PLGA5050 (number average molecular weight 100,000-300,000) in dichloromethane to prepare a PLGA5050 solution with a concentration of 7wt%. Add hydroxyapatite of the same mass as PLGA5050 to the solution, and stir to disperse the hydroxyapatite evenly in the solution. Then, according to the solute mass: porogen mass of 1:5, add sodium chloride particles with a particle size of 200-500μm to the suspension, where the solute mass is the sum of the mass of PLGA5050 and hydroxyapatite, and stir to disperse evenly.

[0061] 2. Then open the container containing the suspension and continue stirring in the fume hood to evaporate the excess dichloromethane until the mixed system is uniform and has no fluidity. Then fill the PLGA / hydroxyapatite / sodium chloride mixture into a φ10mm*h10mm mold and place it in the fume hood for 3 days to solidify and shape.

[0062] 3. Porosity removal treatment: The solidified PLGA / hydroxyapatite / sodium chloride mixture was placed in flowing deionized water for 48 hours to dissolve and remove the sodium chloride. After washing, it was vacuum dried at 30° C. for 24 hours to obtain a porous artificial bone. Figure 1 FIG. 2 is a physical picture of the porous artificial bone obtained in this embodiment. As can be seen from the figure, the artificial bone obtained in this embodiment is a porous block material. Figure 2This is a microscopic image of the artificial bone prepared in this example.

[0063] Example 2

[0064] 1. Construction of the mixed system: PLGA5050 was crushed and then dissolved in dichloromethane, heated and stirred at 40°C in a sealed state to prepare a 30wt% PLGA5050 solution. Hydroxyapatite of the same mass as PLGA5050 was added to the solution, and the hydroxyapatite was evenly dispersed in the solution by stirring. Then, sodium chloride particles with a particle size of 200-500μm were added to the suspension according to the solute mass / porogen mass of 1:5, and stirred evenly to obtain a lumpy PLGA / hydroxyapatite / sodium chloride mixture.

[0065] 2. Fill the mixture into a φ10mm*h10mm mold and place it in a fume hood for 3 days to solidify.

[0066] 3. Porosity removal treatment: The solidified PLGA / hydroxyapatite / sodium chloride mixture was placed in flowing deionized water for 48 hours to dissolve and remove the sodium chloride. After washing, it was vacuum dried at 30° C. for 24 hours to obtain a porous artificial bone.

[0067] Example 3

[0068] 1. Construction of the mixed system: PLGA5050 was dissolved in dichloromethane to prepare a 7wt% PLGA5050 solution. Hydroxyapatite of the same mass as PLGA5050 was added to the solution, and the hydroxyapatite was evenly dispersed in the solution after stirring. Then, sodium chloride particles with a particle size of 200-500μm were added to the suspension at a solute mass / porogen mass ratio of 1:5, and the suspension containing the porogen was evenly stirred to obtain a suspension.

[0069] 2. The suspension was then poured into ethanol to disperse the solvent dichloromethane into the ethanol, and the PLGA / hydroxyapatite / sodium chloride mixture was precipitated. The mixture was then filled into a φ10mm*h10mm mold and placed in a fume hood for 3 days to solidify.

[0070] 3. Porosity removal treatment: The solidified PLGA / hydroxyapatite / sodium chloride mixture was placed in flowing deionized water for 48 hours to dissolve and remove the sodium chloride. After washing, it was vacuum dried at 30° C. for 24 hours to obtain a porous artificial bone.

[0071] Example 4

[0072] 1. Construction of the mixed system: PLGA5050 was dissolved in dichloromethane to prepare a 7wt% PLGA5050 solution. Hydroxyapatite of the same mass as PLGA5050 was added to the solution, and the hydroxyapatite was evenly dispersed in the solution after stirring. Then, sodium chloride particles with a particle size of 200-500μm were added to the suspension at a solute mass / porogen mass ratio of 1:5, and the suspension containing the porogen was evenly stirred to obtain a suspension.

[0073] 2. Then, a φ10mm*h10mm mold was placed in a vacuum freeze drying cabinet, and the cabinet was precooled to -40°C. Finally, the suspension containing the porogen was poured into the mold and vacuum dried for 2 days to obtain a dry PLGA / hydroxyapatite / sodium chloride mixture.

[0074] 3. Porosity removal treatment: The dried PLGA / hydroxyapatite / sodium chloride mixture was placed in flowing deionized water for 48 hours to dissolve and remove the sodium chloride. After washing, it was vacuum dried at 30° C. for 24 hours to obtain a porous artificial bone.

[0075] Performance test of porous artificial bones prepared in Examples 1-4

[0076] 1. Porosity test

[0077] The porosity test method uses the water displacement method, in which the artificial bone is completely immersed in water, the volume of the displaced water is measured, and then the porosity of the material is obtained by calculating the ratio of the volume of the displaced water to the total volume of the material.

[0078] The porosity test results of the porous artificial bones prepared in Examples 1-4 are shown in the following table.

[0079] Example 1 Example 2 Example 3 Example 4 70.2±1.4％ 69.5±0.9％ 72.6±1.9％ 78.4±1.6％

[0080] From the data in the table, it can be seen that the porosity of the porous artificial bones in Examples 1-4 is greater than 70%. Figure 2 The pore size is mainly distributed in the range of 200-500μm, and there are also some micropores smaller than 100μm, which are caused by the volatilization of solvents during the drying process. Micropores provide conditions for cell adhesion and migration, and macropores allow new blood vessels and bone tissue to grow in.

[0081] 2. Compressive strength test

[0082] The compressive strength test method is GB / T 4740-1999 Ceramic Material Compressive Strength Test Method.

[0083] The compressive strength test of the porous artificial bones prepared in Examples 1-4 was performed. The test results are as follows: Figure 3 As shown. Figure 3As shown, the compressive strength of the porous artificial bones prepared in Examples 1 to 4 is all greater than 5 MPa. It can be inferred that the porous artificial bones can play a certain supporting role after being implanted into the defect site and can effectively play a role of bone conduction.

[0084] 3. Application of porous artificial bone in the repair of rabbit femoral condyle defect

[0085] The artificial bone obtained in Example 1 was trimmed and implanted into a rabbit femoral condyle bone defect model of φ6mm*h6mm, and a blank control group was set up. The blank control group did not contain the porous artificial bone.

[0086] Test method: All animals were euthanized, and the test parts were cut separately and fixed with 10% neutral formalin for more than 48 hours. Micro-CT (Bruker skyscan 1176) scanning was performed with a scanning resolution of 18μm and a segmentation threshold of 120-255. The raw data obtained from the scan was reconstructed into a 3D image for analysis. The set area (TV set area volume) was the defect implantation site (φ6mm*h6mm), and the bone volume (BV) data of the implantation site was obtained by analysis.

[0087] Micro-CT quantitative detection was performed on the implantation site of the porous artificial bone at 1M (month), 3M, 6M and 12M. The detection results are shown in the following table.

[0088]

[0089]

[0090] It can be seen from the data in the table that during the experiment, the bone volume of the Example 1 group was always increasing, and the bone tissue ratio (BV / TV) was always much higher than that of the blank control group. It can be seen that in the process of repairing rabbit femoral condyle bone defects, the porous artificial bone prepared in this example can provide mechanical support and maintain bone formation space in the early stage of implantation, and can also participate in the reconstruction of bone tissue in the later stage.

[0091] The in vitro physical properties of the artificial bones obtained in Examples 2-4 were evaluated, and the physical properties of the three groups of artificial bones were close to those of the artificial bones obtained in Example 1. Although no animal experiments were conducted, it can be inferred that the artificial bones obtained in Examples 2-4 also have ideal bone repair capabilities.

[0092] Therefore, the porous artificial bone of the present invention has a pore structure and mechanical properties that are conducive to bone regeneration, the pore size is mainly distributed in 200-500 μm, the porosity is greater than 70%, the mechanical properties are suitable, and the compressive strength of the porous artificial bones prepared in Examples 1-4 is greater than 5 MPa. After the porous artificial bones are implanted in the defect site, they can effectively play the role of bone conduction, which is very conducive to bone regeneration. The preparation method of the porous artificial bone of the present invention is simple, stable and effective, and is absorbable and low in cost, and has a large market and potential to replace existing conventional artificial bone products.

[0093] The above embodiments are only used to illustrate the present invention, rather than to limit the present invention. Those skilled in the relevant technical field may make various changes or modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions should also belong to the scope of the present invention and should be defined by the claims.

Claims

1. A porous artificial bone, characterized in that: Its components include absorbable polymer and orthopedic inorganic implant material, the mass ratio of the absorbable polymer to the orthopedic inorganic implant material is 1:0.1-2, the porous artificial bone has a through porous structure, the porosity is greater than 70%, and the pore size distribution range is less than 500μm.

2. A method for preparing a porous artificial bone as claimed in claim 1, characterized in that: The following steps are included: (1) weighing an absorbable polymer, an orthopedic inorganic implant material, a porogen, and a good solvent according to a ratio, dissolving the absorbable polymer in the good solvent to obtain an absorbable polymer solution, adding the orthopedic inorganic implant material and the porogen to the absorbable polymer solution, and mixing them uniformly to obtain a plastic mixture; (2) pouring the plastic mixture obtained in step (1) into a mold, drying and solidifying it into a mold; (3) The mixture solidified and formed in step (2) is treated to remove the porogen and dried to obtain a porous artificial bone.

3. The preparation method according to claim 2, characterized in that: The plastic mixture in step (1) is a plastic mass-like mixture, and the preparation method thereof comprises one of the following: Prepare an absorbable polymer solution with a concentration of 5-10wt%, add an orthopedic inorganic implant material and a porogen, mix well, and continue stirring to evaporate the solvent until the concentration of the absorbable polymer solution is not less than 20wt%, thereby obtaining a plastic mass-like mixture; Prepare an absorbable polymer solution with a concentration of not less than 20wt%, add an orthopedic inorganic implant material and a porogen, mix well, and obtain a plastic mass-like mixture; Prepare an absorbable polymer solution with a concentration of 5-10wt%, add orthopedic inorganic implant material and porogen, mix evenly to obtain a suspension, pour the suspension into a poor solvent for the absorbable polymer, and the mixture precipitates and settles to obtain a plastic mass-like mixture.

4. The preparation method according to claim 2, characterized in that: The drying method of step (2) is freeze drying, static drying at room temperature, or forced air drying at a temperature below the boiling point of the solvent, and the drying time is 1 day to 5 days.

5. A method for preparing a porous artificial bone as claimed in claim 1, characterized in that: The following steps are included: (1) weighing an absorbable polymer, an orthopedic inorganic implant material, a porogen, and a good solvent according to a ratio, dissolving the absorbable polymer in the good solvent to obtain an absorbable polymer solution, adding the orthopedic inorganic implant material and the porogen to the absorbable polymer solution, and mixing them uniformly to obtain a suspension; (2) pouring the suspension obtained in step (1) into a mold and rapidly freezing and freeze-drying the mixture; (3) The mixture obtained by freeze-drying in step (2) is treated to remove the porogen and dried to obtain a porous artificial bone.

6. The preparation method according to claim 5, characterized in that: The rapid freezing method in step (2) includes liquid nitrogen freezing, or precooling the freeze dryer to a set temperature and then quickly pouring the suspension into a mold inside the freeze dryer cabinet.

7. The porous artificial bone prepared by the preparation method according to claim 1 or any one of claims 2 to 6, characterized in that: The absorbable polymer is an absorbable polyester, which includes at least one of polylactic acid and lactide-glycolide copolymer. The orthopedic inorganic implant material includes at least one of calcium phosphate, hydroxyapatite, β-tricalcium phosphate and bioactive glass.

8. The preparation method according to any one of claims 2 to 6, characterized in that: The amount of the porogen is 1-20 times the total mass of the absorbable polymer and the orthopedic inorganic implant material, and the porogen is sodium chloride or ammonium bicarbonate.

9. The preparation method according to any one of claims 2 to 6, characterized in that: The treatment method for removing the porogen is to wash with pure water, change the water regularly or place the mixture in flowing water, and the treatment time is 2-5 days; the drying method after removing the porogen is vacuum drying, the drying temperature is 30-40° C., and the drying time is 18-48 hours.

10. A method for using a porous artificial bone prepared by the preparation method according to claim 1 or any one of claims 2 to 6, comprising the steps of: debridement of a bone defect, trimming the porous artificial bone according to the size and shape of the bone defect, filling the porous artificial bone into the bone defect, and finally suturing.

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