Implantable absorbable PLA composite material and preparation method thereof

Abstract

The invention discloses an implantable absorbable PLA composite material and a preparation method thereof, and relates to the technical field of medical materials. The implantable absorbable PLA composite material is prepared from the following raw materials in parts by weight: 60 to 70 parts of PLA, 5 to 10 parts of poly (lactic-co-glycolic acid), 8 to 12 parts of polycaprolactone, 5 to 8 parts of modified hydroxyapatite, 2 to 3 parts of a toughening agent and 0.2 to 0.6 part of an antioxidant, the toughening agent is prepared by the following steps: reacting hydroxyethyl methylacrylate with ethylenediamine to prepare a four-arm compound, reacting the four-arm compound with 1-chloro-4-isocyanatobutane to prepare an isocyanate compound, and finally reacting the isocyanate compound with polyethylene glycol. The implantable absorbable PLA composite material prepared by the invention has excellent tensile property and impact resistance, and can meet the application requirements of clinical medical treatment.

Description

Technical Field

[0001] The present invention relates to the technical field of medical materials, and particularly relates to an implantable absorbable PLA composite material and a preparation method thereof. Background Art

[0002] As an absorbable implant material, polylactic acid (PLA) has good biodegradability and biocompatibility, which can reduce the pain of secondary surgery removal and reduce the risk of postoperative infection and tissue rejection. However, its high brittleness, poor toughness, low melt strength and other defects are difficult to meet the implant requirements of high strength and high load, which limits its application in the field of medical materials. In order to improve the mechanical properties of PLA composites, some nano-fillers are generally added, such as hydroxyapatite. However, the dispersion of nano-fillers in the PLA matrix is relatively poor, and it is easy to form nano-filler agglomeration, which affects the overall performance of the material. Summary of the Invention

[0003] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide an implantable absorbable PLA composite material and a preparation method thereof.

[0004] To achieve the above purpose, the present invention is realized through the following technical solutions: An implantable absorbable PLA composite material, comprising the following raw materials in parts by weight: 60-70 parts of PLA, 5-10 parts of poly (ethylene-co-glycolide), 8-12 parts of polycaprolactone, 5-8 parts of modified hydroxyapatite, 2-3 parts of toughening agent, 0.2-0.6 parts of antioxidant; The toughening agent is prepared by reacting hydroxyethyl methacrylate with ethylenediamine to obtain a tetra-armed compound, then reacting with 1-chloro-4-isocyanatobutane to obtain an isocyanate compound, and finally reacting with polyethylene glycol.

[0005] The toughening agent is prepared by the following method: S1: Hydroxyethyl methacrylate and ethylenediamine react in a methanol solution to form a tetra-armed compound; S2: The tetra-armed compound reacts with 1-chloro-4-isocyanatobutane under alkaline conditions to obtain an isocyanate compound; S3: The isocyanate compound reacts with polyethylene glycol under the action of the catalyst dibutyltin dilaurate to obtain a toughening agent, wherein the isocyanate group (-NCO) of the isocyanate compound reacts with the hydroxyl group (-OH) of polyethylene glycol under the action of the dibutyltin dilaurate catalyst to form a urethane bond (-NH-CO-O-).

[0006] In step S1, the feeding molar ratio of hydroxyethyl methacrylate to ethylenediamine is 1:(4-4.5).

[0007] The molar ratio of the tetra-arm compound to 1-chloro-4-isocyanatobutane described in step S2 is 1:(4.2 - 4.6).

[0008] The mass ratio of the isocyanate compound to polyethylene glycol described in step S3 is (2.3 - 2.6):1.

[0009] The modified hydroxyapatite is prepared by the following method: N1: Hydroxyapatite reacts with 3-glycidoxypropyltrimethoxysilane to form silane-modified apatite; wherein, the silanemethoxy of 3-glycidoxypropyltrimethoxysilane hydrolyzes to form silanol groups, and the silanol groups undergo a condensation reaction with the hydroxyl groups of hydroxyapatite. N2: The silane-modified apatite reacts with dopamine to form modified hydroxyapatite; wherein, the epoxy group of the silane-modified apatite undergoes a nucleophilic ring-opening addition reaction with the amino group of dopamine to obtain hydroxy secondary amine.

[0010] The mass ratio of the hydroxyapatite to 3-glycidoxypropyltrimethoxysilane described in step N1 is 10:1.

[0011] The mass ratio of the silane-modified apatite to dopamine described in step N2 is 15:1.

[0012] The antioxidant is catechol.

[0013] A preparation method of an implantable absorbable PLA composite material includes the following steps: (1) Weigh by weight: 60 - 70 parts of PLA, 5 - 10 parts of poly (ethyl glycolide-co-lactide), 8 - 12 parts of polycaprolactone, 5 - 8 parts of modified hydroxyapatite, 2 - 3 parts of toughening agent, and 0.2 - 0.6 parts of antioxidant; (2) Add the above components into a high-speed mixer for mixing, then introduce the mixture into a twin-screw extruder for extrusion granulation, and air-cool and screen to obtain the implantable absorbable PLA composite material.

[0014] Due to the above technical solutions, the beneficial effects of the present invention include: (1) In the toughening agent prepared by the present invention, the urethane improves its interfacial adhesion, and the flexible polyethylene glycol improves the interfacial compatibility. The two work together to improve the mechanical properties of the material.

[0015] (2) The modified hydroxyapatite prepared by the present invention improves the steric hindrance effect and biocompatibility by introducing siloxane and dopamine, and realizes the uniform dispersion of hydroxyapatite. Description of the Drawings

[0016] Figure 1 It is a schematic diagram of the reaction equation of step S1 for preparing the toughening agent; Figure 2 Schematic diagram of the reaction equation for the preparation step S2 of the toughening agent; Figure 3 1H NMR spectrum of the four-arm compound prepared in step S1 of Example 1; Figure 4 1H NMR spectrum of the isocyanate compound prepared in step S2 of Example 1. Specific embodiments

[0017] The following is further described in conjunction with examples, but the present invention is not limited to these examples.

[0018] Example 1 Preparation of toughening agent: S1: In an ice-water bath, 500 ml of methanol and 1 mol of ethylenediamine were added to the reaction kettle. Under nitrogen protection, 4 mol of 2-hydroxyethyl methacrylate was added dropwise. The addition was completed in 2 h, and the temperature was raised to room temperature for reaction for 20 h. Then, vacuum distillation was carried out at 50 °C for 3 h to obtain a pale yellow liquid four-arm compound. The 1H NMR data are as follows: 1 H NMR (300 MHz, DMSO-d6) δ 4.65 (t, J = 6.4 Hz, 4H), 4.27 - 4.09 (m, 8H), 3.78 (dt, J = 6.3, 4.7 Hz, 8H), 2.98 - 2.87 (m, 4H), 2.81 - 2.60 (m, 8H), 2.57 (d, J = 3.4 Hz, 4H), 1.18 - 1.03 (m, 12H); S2: Under nitrogen protection, 400 ml of anhydrous THF, 0.5 mol of potassium tert-butoxide, and 0.1 mol of the four-arm compound were added to the reaction kettle. Stir at room temperature for 1 h, cool down to 0 °C, and add dropwise 100 ml of a THF solution containing 0.42 mol of 1-chloro-4-isocyanatobutane. The addition was completed in 1 h, and the temperature was raised to room temperature for reaction for 3 h. Then, 300 ml of ice water was added, and vacuum distillation was carried out at 40 °C for 3 h. Extraction was carried out three times with dichloromethane (500 ml each time), and the organic phases were combined. The combined organic phase was washed with 500 ml of deionized water, dried with 80 g of anhydrous sodium sulfate, filtered, and vacuum distilled at 30 °C for 3 h to obtain an isocyanate compound. The 1H NMR data are as follows: 11H NMR (300 MHz, DMSO-d6) δ 4.39 - 4.21 (m, 8H), 3.81 (t, J = 5.1 Hz, 8H), 3.52 - 3.42 (m, 8H), 3.20 - 3.05 (m, 8H), 2.93 - 2.72 (m, 8H), 2.67 - 2.55 (m, 4H), 2.49 (d, J = 3.3 Hz, 4H), 1.89 - 1.70 (m, 16H), 1.11 (d, J = 8.0 Hz, 12H); S3: Under nitrogen protection, 2000 ml of DMF, 230 g of isocyanate compound, and 100 g of polyethylene glycol (PEG - 800) were successively added to the reaction kettle, stirred and mixed evenly, 10 g of dibutyltin dilaurate was added, the temperature was raised to 30 °C, and the reaction was carried out for 8 h. 3000 ml of deionized water was added to precipitate the solid, filtered, washed with 800 ml of deionized water, and dried in vacuo at 50 °C for 6 h to obtain the toughening agent.

[0019] Example 2 Preparation of toughening agent: S1: In an ice - water bath, 500 ml of methanol and 1 mol of ethylenediamine were added to the reaction kettle. Under nitrogen protection, 4.3 mol of 2 - hydroxyethyl methacrylate was added dropwise, and the addition was completed in 2 h. The temperature was raised to room temperature and the reaction was carried out for 24 h. Then, it was distilled under reduced pressure at 50 °C for 3 h to obtain a light - yellow liquid tetra - arm compound; S2: Under nitrogen protection, 400 ml of anhydrous THF, 0.5 mol of potassium tert - butoxide, and 0.1 mol of tetra - arm compound were added to the reaction kettle, stirred at room temperature for 1 h, cooled to 0 °C, and 100 ml of a THF solution containing 0.45 mol of 1 - chloro - 4 - isocyanatobutane was added dropwise. The addition was completed in 1 h. The temperature was raised to room temperature and the reaction was carried out for 4 h. 300 ml of ice - water was added, and it was distilled under reduced pressure at 40 °C for 3 h. It was extracted three times with dichloromethane (500 ml each time), the organic phases were combined, washed with 500 ml of deionized water, the organic phase was dried with 80 g of anhydrous sodium sulfate, filtered, and distilled under reduced pressure at 30 °C for 3 h to obtain the isocyanate compound; S3: Under nitrogen protection, 2000 ml of DMF, 250 g of isocyanate compound, and 100 g of polyethylene glycol (PEG - 800) were successively added to the reaction kettle, stirred and mixed evenly, 10 g of dibutyltin dilaurate was added, the temperature was raised to 40 °C, and the reaction was carried out for 7 h. 3000 ml of deionized water was added to precipitate the solid, filtered, washed with 800 ml of deionized water, and dried in vacuo at 50 °C for 6 h to obtain the toughening agent.

[0020] Example 3 Preparation of toughening agent: S1: In an ice-water bath, add 500 ml of methanol and 1 mol of ethylenediamine to a reaction kettle. Dropwise add 4.5 mol of 2-hydroxyethyl methacrylate under nitrogen protection. The dropping is completed in 2 h. Then raise the temperature to room temperature and react for 26 h. Distill under reduced pressure at 50 °C for 3 h to obtain a four-armed compound as a light yellow liquid. S2: Under nitrogen protection, add 400 ml of anhydrous THF, 0.5 mol of potassium tert-butoxide, and 0.1 mol of the four-armed compound to a reaction kettle. Stir at room temperature for 1 h, then cool down to 0 °C. Dropwise add 100 ml of a THF solution containing 0.46 mol of 1-chloro-4-isocyanatobutane. The dropping is completed in 1 h. Then raise the temperature to room temperature and react for 5 h. Add 300 ml of ice water. Distill under reduced pressure at 40 °C for 3 h. Extract with dichloromethane three times (500 ml each time). Combine the organic phases, wash with 500 ml of deionized water. Dry the organic phase with 80 g of anhydrous sodium sulfate, filter, and distill under reduced pressure at 30 °C for 3 h to obtain an isocyanate compound. S3: Under nitrogen protection, add 2000 ml of DMF, 260 g of the isocyanate compound, and 100 g of polyethylene glycol (PEG-800) to a reaction kettle in sequence. Stir and mix evenly. Add 10 g of dibutyltin dilaurate. Raise the temperature to 50 °C and react for 6 h. Add 3000 ml of deionized water to precipitate solids. Filter, wash with 800 ml of deionized water, and dry in vacuum at 50 °C for 6 h to obtain the toughening agent.

[0021] Example 4 Preparation of modified hydroxyapatite: N1: Stir 500 g of deionized water and 100 g of hydroxyapatite for 1 h. Adjust the pH value to 4.0 with acetic acid. Add 200 ml of a deionized water solution containing 10 g of 3-glycidoxypropyltrimethoxysilane. Stir at room temperature for 8 h, filter, and wash with deionized water three times (300 ml each time). Dry in vacuum at 120 °C for 12 h to obtain silane-modified apatite. N2: Under nitrogen protection, put 800 ml of DMF and 10 g of dopamine into a reaction kettle in sequence. Raise the temperature to 80 °C. Batchwise add 150 g of the silane-modified apatite (in 10 batches, with an interval of 10 min between each batch), stir, and keep the temperature for reaction for 24 h. Cool down to room temperature. Adjust the pH to 3 with 1 M HCl solution to precipitate the precipitate. Wash with deionized water (200 ml × 3 times), and dry in vacuum at 70 °C for 10 h to obtain the modified hydroxyapatite.

[0022] Example 5 Preparation of implantable absorbable PLA composite material: (1) Weigh 600 g of PLA, 50 g of poly (ethyl glycolide-co-lactide), 80 g of polycaprolactone, 50 g of the modified hydroxyapatite (prepared in Example 4), 20 g of the toughening agent (prepared in Example 1), and 2 g of antioxidant (catechol). (2) Add the above components into a high-speed mixer for mixing. The mixing temperature is 160°C, the mixing speed is 50 r / min, and the mixing time is 10 min. Then, introduce the mixed material into a twin-screw extruder for extrusion granulation. The screw speed of the screw extruder is 10 r / s. The temperature of the conveying section of the twin-screw extruder is 160°C, the melting section temperature is 170°C, the kneading section temperature is 175°C, and the homogenization section temperature is 160°C. After air cooling and sieving, the implantable absorbable PLA composite material is obtained.

[0023] Example 6 Preparation of implantable absorbable PLA composite material: (1) Weigh 680 g of PLA, 80 g of poly (ethylene glycol-co-glycolide), 110 g of polycaprolactone, 70 g of modified hydroxyapatite (prepared in Example 4), 26 g of toughening agent (prepared in Example 2), and 5 g of antioxidant (catechol); (2) Add the above components into a high-speed mixer for mixing. The mixing temperature is 170°C, the mixing speed is 80 r / min, and the mixing time is 20 min. Then, introduce the mixed material into a twin-screw extruder for extrusion granulation. The screw speed of the screw extruder is 10 r / s. The temperature of the conveying section of the twin-screw extruder is 170°C, the melting section temperature is 180°C, the kneading section temperature is 185°C, and the homogenization section temperature is 170°C. After air cooling and sieving, the implantable absorbable PLA composite material is obtained.

[0024] Example 7 Preparation of implantable absorbable PLA composite material: (1) Weigh 700 g of PLA, 100 g of poly (ethylene glycol-co-glycolide), 120 g of polycaprolactone, 80 g of modified hydroxyapatite (prepared in Example 4), 30 g of toughening agent (prepared in Example 3), and 6 g of antioxidant (catechol);

[0025] (2) Add the above components into a high-speed mixer for mixing. The mixing temperature is 160°C, the mixing speed is 80 r / min, and the mixing time is 10 min. Then, introduce the mixed material into a twin-screw extruder for extrusion granulation. The screw speed of the screw extruder is 10 r / s. The temperature of the conveying section of the twin-screw extruder is 160°C, the melting section temperature is 170°C, the kneading section temperature is 175°C, and the homogenization section temperature is 160°C. After air cooling and sieving, the implantable absorbable PLA composite material is obtained.

[0026] Comparative Example 1

[0027] The raw material composition and process of the implantable absorbable PLA composite material are basically the same as those in Example 6. The difference is that the toughening agent (prepared in Example 2) added in the components is replaced with an equal mass of isocyanate compound (prepared in step S2 of Example 2).

[0028] Comparative Example 2 The raw material composition and process of the implantable absorbable PLA composite material are basically the same as those of Example 6, except that the toughening agent added in the components (prepared in Example 2) is replaced with a toughening agent prepared by the following method in an equal mass: The preparation method of the toughening agent is basically the same as that of Example 2, except that polyethylene glycol (PEG-800) in step S3 is replaced with an equal weight of polyethylene glycol (PEG-400).

[0029] Comparative Example 3 The raw material composition and process of the implantable absorbable PLA composite material are basically the same as those of Example 6, except that the toughening agent added in the components (prepared in Example 2) is replaced with a toughening agent prepared by the following method in an equal mass:

[0030] The preparation method of the toughening agent is basically the same as that of Example 2, except that polyethylene glycol (PEG-800) in step S3 is replaced with an equal weight of polyethylene glycol (PEG-10000).

[0031] Comparative Example 4 The raw material composition and process of the implantable absorbable PLA composite material are basically the same as those of Example 6, except that the modified hydroxyapatite added in the components (prepared in Example 4) is replaced with an equal mass of unmodified hydroxyapatite.

[0032] Comparative Example 5 The raw material composition and process of the implantable absorbable PLA composite material are basically the same as those of Example 6, except that the modified hydroxyapatite added in the components (prepared in Example 4) is replaced with an equal mass of silane-modified apatite (step N1 of Example 4).

[0033] Comparative Example 6 The raw material composition and process of the implantable absorbable PLA composite material are basically the same as those of Example 6, except that the modified hydroxyapatite added in the components (prepared in Example 4) is replaced with a modified hydroxyapatite prepared by the following method in an equal mass: Stir 500 g of deionized water and 100 g of hydroxyapatite for 1 h, adjust the pH value to 4.0 with acetic acid, add 200 ml of deionized water solution containing 10 g of dopamine, stir at room temperature for 8 h, filter, and wash with deionized water 3 times (300 ml each time), and vacuum dry at 120 °C for 12 h to obtain silane-modified apatite.

[0034] Comparative Example 7 The raw material composition and process of the implantable absorbable PLA composite material are basically the same as those of Example 6, except that the modified hydroxyapatite added in the components (prepared in Example 4) is replaced with a modified hydroxyapatite prepared by the following method in an equal mass: The preparation method of the modified hydroxyapatite is basically the same as that of Example 4, except that 3-glycidoxypropyltrimethoxysilane in step N1 is replaced with an equal weight of [8-(glycidyloxy)-n-octyl]trimethoxysilane.

[0035] Comparative Example 8 The raw material composition and process of the implantable absorbable PLA composite material are basically the same as those of Example 6, except that the modified hydroxyapatite (prepared in Example 4) added in the components is replaced with an equal mass of modified hydroxyapatite prepared by the following method: The preparation method of the modified hydroxyapatite is basically the same as that of Example 4, except that dopamine in step N2 is replaced with an equal weight of 4-amino-2-hydroxymethyl-1-butanol.

[0036] The model of PLA used in Examples 5-7 and Comparative Examples 1-8 of this application is JHMS®PL25, with a molecular weight of 250,000, produced by Sichuan Zhuoxin Biomedical Materials Research Co., Ltd.; the models of poly (lactide-co-glycolide) and polycaprolactone are PLG75-10 and PCL-20 respectively, produced by Shenzhen Boli Biomedical Materials Co., Ltd.; the model of hydroxyapatite is HAP04-20, produced by Nanjing Junzhuo Biotechnology Co., Ltd.

[0037] The implantable absorbable PLA composite materials prepared in Examples 5-7 and Comparative Examples 1-8 were subjected to tensile strength, elongation at break, and notched impact strength tests.

[0038] The tensile strength and elongation at break were carried out according to GB / T 1040.2-2022, and a dumbbell-shaped sample with a thickness of 0.4 mm was tested at a speed of 10 mm / min; the notched impact strength was carried out according to the ASTM D256 standard, the pendulum mass was 0.668 kg, the speed was 0.46 m / s, and the pendulum energy was 4 J. The test results are shown in Table 1. Table 1 Performance test data table

[0039] Item Tensile strength MPa Elongation at break % <![CDATA[Notched impact strength kJ / m 2 > Example 5 51.3 282.6 68.2 Example 6 53.2 288.2 70.1 Example 7 52.8 285.7 67.5 Comparative Example 1 45.2 203.9 51.6 Comparative Example 2 49.4 258.7 65.3 Comparative Example 3 48.3 291.3 62.1 Comparative Example 4 36.8 196.7 41.6 Comparative Example 5 45.2 243.6 52.4 Comparative Example 6 48.6 257.4 56.7 Comparative Example 7 51.7 267.2 63.2 Comparative Example 8 50.1 297.3 60.1

[0040] It can be seen from Examples 5, 6, and 7 in Table 1 that the implantable absorbable PLA composite material prepared by the present invention has excellent tensile properties and impact resistance.

[0041] The urethane in the toughening agent prepared in this application can form hydrogen bonds with PLA molecules, which can enhance the interfacial adhesion, enable the material to uniformly transfer stress during the stretching process, and delay fracture; introducing a flexible polyethylene glycol segment can improve the molecular entanglement and compatibility of PLA, polyethylenepropylene glycolide, and polycaprolactone, and its high flexibility and degree of freedom of movement can effectively disperse external stress and improve the tensile properties. The unreacted isocyanate groups in the toughening agent can react with the hydroxyl groups of PLA during the melting process, further enhancing the interfacial bonding strength. In addition, the toughening agent prepared in this application introduces a large number of ester groups through 2-hydroxyethyl methacrylate, which is conducive to the degradation of the toughening agent. The flexible polyethylene glycol segment introduced in the plasticizer used in Comparative Example 2 has a limited length, and the effect of dispersing external stress through molecular chain slip is limited, resulting in a decrease in the elongation at break of the material.

[0042] The modified hydroxyapatite prepared in this invention improves the dispersibility of hydroxyapatite by introducing siloxane, and can enhance the interfacial compatibility with the PLA matrix through ether bonds and hydroxyl groups, improving its mechanical properties. The modified hydroxyapatite prepared in this invention introduces hydroxyl groups through dopamine, which can enhance the interfacial bonding strength with the polylactic acid matrix through hydrogen bonding, further improving the mechanical properties of the material, and the presence of the rigid benzene ring structure improves the tensile strength of the material. The modified hydroxyapatite used in Comparative Example 6 only has dopamine for surface modification of hydroxyapatite. The benzene ring structure of dopamine is too rigid and lacks flexibility, resulting in a decrease in the mechanical properties of the material. The modified hydroxyapatite used in Comparative Example 7 contains long-chain alkyl groups, which have poor compatibility with the PLA matrix, thus affecting the mechanical properties of the material.

[0043] The above are only the preferred embodiments of the present invention and are not used to limit the present invention; however, for those of ordinary skill in the art, without departing from the scope of the technical solution of the present invention, some equivalent changes such as slight modifications, decorations, and evolutions made using the technical content disclosed above are all equivalent embodiments of the present invention; at the same time, any equivalent changes, modifications, and evolutions made to the above embodiments based on the essential technology of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. An implantable absorbable PLA composite material, characterized in that, It includes raw materials in the following parts by weight: 60 - 70 parts of PLA, 5 - 10 parts of poly(ethyl-co-glycolide), 8 - 12 parts of polycaprolactone, 5 - 8 parts of modified hydroxyapatite, 2 - 3 parts of toughening agent, 0.2 - 0.6 part of antioxidant; The toughening agent is prepared by reacting hydroxyethyl methacrylate with ethylenediamine to obtain a tetra-armed compound, then reacting with 1-chloro-4-isocyanatobutane to obtain an isocyanate compound, and finally reacting with polyethylene glycol.

2. The implantable absorbable PLA composite material according to claim 1, wherein The toughening agent is prepared by the following method: S1: Hydroxyethyl methacrylate and ethylenediamine react in a methanol solution to form a tetra-armed compound; S2: The tetra-armed compound reacts with 1-chloro-4-isocyanatobutane under alkaline conditions to obtain an isocyanate compound; S3: The isocyanate compound reacts with polyethylene glycol under the action of the catalyst dibutyltin dilaurate to obtain the toughening agent.

3. An implantable absorbable PLA composite material according to claim 2, characterized in that, In step S1, the feeding molar ratio of hydroxyethyl methacrylate to ethylenediamine is 1:(4 - 4.5).

4. The implantable absorbable PLA composite material according to claim 2, characterized in that, In step S2, the feeding molar ratio of the tetra-armed compound to 1-chloro-4-isocyanatobutane is 1:(4.2 - 4.6).

5. An implantable absorbable PLA composite material according to claim 2, characterized in that, In step S3, the feeding mass ratio of the isocyanate compound to polyethylene glycol is (2.3 - 2.6):

1.

6. An implantable absorbable PLA composite material according to claim 1, wherein, The modified hydroxyapatite is prepared by the following method: N1: Hydroxyapatite reacts with 3-glycidoxypropyltrimethoxysilane to form silane-modified apatite; N2: The silane-modified apatite reacts with dopamine to form modified hydroxyapatite.

7. An implantable absorbable PLA composite material according to claim 6, characterized in that, In step N1, the feeding mass ratio of hydroxyapatite to 3-glycidoxypropyltrimethoxysilane is 10:

1.

8. An implantable absorbable PLA composite material according to claim 6, characterized in that, In step N2, the feeding mass ratio of the silane-modified apatite to dopamine is 15:

1.

9. The implantable absorbable PLA composite material according to claim 1, wherein The antioxidant is catechol.

10. A method for preparing the implantable absorbable PLA composite material according to any one of claims 1-9, characterized in that, It includes the following steps: (1) Weigh by parts by weight: 60 - 70 parts of PLA, 5 - 10 parts of poly(ethyl-co-glycolide), 8 - 12 parts of polycaprolactone, 5 - 8 parts of modified hydroxyapatite, 2 - 3 parts of toughening agent, 0.2 - 0.6 part of antioxidant; (2) Add the above components into a high-speed mixer for mixing, then introduce the mixed material into a twin-screw extruder for extrusion granulation, and air-cool and screen to obtain the implantable absorbable PLA composite material.

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