Implantable absorbable PLA composite material and preparation method thereof

Abstract

The present invention discloses an implantable absorbable PLA composite material and a preparation method thereof, relating to the field of medical material technology. The implantable absorbable PLA composite material comprises the following raw materials in parts by weight: PLA: 60-70 parts, poly(lactide-co-glycolide) 5-10 parts, polycaprolactone 8-12 parts, modified hydroxyapatite 5-8 parts, a toughening agent 2-3 parts, and an antioxidant 0.2-0.6 parts; the toughening agent is prepared by reacting hydroxyethyl methacrylate with ethylenediamine to form a four-arm compound, which is then reacted with 1-chloro-4-isocyanatobutane to form an isocyanate compound, and finally reacted with polyethylene glycol. The implantable absorbable PLA composite material prepared by the present invention has excellent tensile properties and impact resistance, which can meet the application requirements of clinical medicine.

Description

Technical Field

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

[0002] Polylactic acid (PLA), as an absorbable implant material, exhibits excellent biodegradability and biocompatibility, reducing the pain of secondary surgical removal and lowering the risk of postoperative infection and tissue rejection. However, its high brittleness, poor toughness, and low melt strength make it difficult to meet the demands of high-strength, high-load implants, limiting its application in medical materials. To enhance the mechanical properties of PLA composites, nanofillers, such as hydroxyapatite, are typically added. However, nanofillers have relatively poor dispersion in the PLA matrix, leading to the formation of nanofiller agglomerates, which can affect the overall performance of the material. Summary of the Invention

[0003] In view of the shortcomings of the prior art, the present invention aims to provide an implantable absorbable PLA composite material and a preparation method thereof.

[0004] To achieve the above object, the present invention is implemented through the following technical solutions:

[0005] An implantable absorbable PLA composite material comprises the following raw materials in parts by weight:

[0006] PLA 60-70 parts, poly (lactide-glycol) 5-10 parts, polycaprolactone 8-12 parts, modified hydroxyapatite 5-8 parts, toughening agent 2-3 parts, antioxidant 0.2-0.6 parts;

[0007] The toughening agent is prepared by reacting hydroxyethyl methacrylate with ethylenediamine to obtain a four-arm compound, then reacting with 1-chloro-4-isocyanatobutane to obtain an isocyanate compound, and finally reacting with polyethylene glycol.

[0008] The toughening agent is prepared by the following method:

[0009] S1: Hydroxyethyl methacrylate reacts with ethylenediamine in methanol solution to form a four-arm compound;

[0010] S2: The four-arm compound reacts with 1-chloro-4-isocyanatobutane under alkaline conditions to obtain an isocyanate compound;

[0011] S3: An isocyanate compound reacts with polyethylene glycol in the presence of a dibutyltin dilaurate catalyst to obtain a toughening agent, wherein the isocyanate group (-NCO) of the isocyanate compound undergoes a nucleophilic addition reaction with the hydroxyl group (-OH) of the polyethylene glycol in the presence of the dibutyltin dilaurate catalyst to form a carbamate bond (-NH-CO-O-).

[0012] The molar ratio of hydroxyethyl methacrylate to ethylenediamine in step S1 is 1:(4-4.5).

[0013] The molar ratio of the four-arm compound to 1-chloro-4-isocyanatobutane in step S2 is 1:(4.2-4.6).

[0014] The mass ratio of the isocyanate compound to the polyethylene glycol in step S3 is (2.3-2.6):1.

[0015] The modified hydroxyapatite is prepared by the following method:

[0016] N1: Hydroxyapatite reacts with 3-glycidyloxypropyltrimethoxysilane to form silane-modified apatite; wherein the silanyl methoxy group of 3-glycidyloxypropyltrimethoxysilane is hydrolyzed to form silanol groups, which then undergo a condensation reaction with the hydroxyl groups of hydroxyapatite;

[0017] N2: Silane-modified apatite reacts with dopamine to generate modified hydroxyapatite; wherein the epoxy group of the silane-modified apatite and the amino group of the dopamine undergo a nucleophilic ring-opening addition reaction to obtain a hydroxyl secondary amine.

[0018] The mass ratio of hydroxyapatite to 3-glycidyloxypropyltrimethoxysilane in step N1 is 10:1.

[0019] The mass ratio of the silane-modified apatite to dopamine in step N2 is 15:1.

[0020] The antioxidant is catechol.

[0021] A method for preparing an implantable absorbable PLA composite material comprises the following steps:

[0022] (1) Weigh by weight: 60-70 parts of PLA, 5-10 parts of poly(lactide-glycol) copolymer, 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;

[0023] (2) The above components are added into a high-speed mixer and mixed, and then the mixture is introduced into a twin-screw extruder for extrusion and granulation, and air-cooled and sieved to obtain an implantable absorbable PLA composite material.

[0024] Due to the adoption of the above technical solution, the beneficial effects of the present invention include:

[0025] (1) The carbamate in the toughening agent prepared by the present invention improves its interfacial adhesion, and the flexible polyethylene glycol improves its interfacial compatibility, and the two work synergistically to improve the mechanical properties of the material.

[0026] (2) The modified hydroxyapatite prepared by the present invention improves the steric hindrance effect and biocompatibility by introducing siloxane and dopamine, thereby achieving uniform dispersion of hydroxyapatite. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the reaction equation for the toughening agent preparation step S1;

[0028] Figure 2 Schematic diagram of the reaction equation for the toughening agent preparation step S2;

[0029] Figure 3 This is the H NMR spectrum of the four-arm compound prepared in step S1 of Example 1;

[0030] Figure 4 This is the H NMR spectrum of the isocyanate compound prepared in step S2 of Example 1. DETAILED DESCRIPTION

[0031] The present invention will be further described below with reference to the embodiments, but the present invention is not limited to these embodiments.

[0032] Example 1 Preparation of toughening agent:

[0033] S1: In an ice-water bath, 500 ml of methanol and 1 mol of ethylenediamine were added to a reaction kettle. 4 mol of hydroxyethyl methacrylate was added dropwise under nitrogen over a period of 2 h. The mixture was allowed to react at room temperature for 20 h. The mixture was then distilled under reduced pressure at 50°C for 3 h to obtain a pale yellow liquid four-arm compound. Its H NMR spectrum 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);

[0034] 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, stirred at room temperature for 1 h, cooled to 0°C, and 100 ml of a THF solution containing 0.42 mol of 1-chloro-4-isocyanatobutane was added dropwise. The temperature was raised to room temperature for 3 h, 300 ml of ice water was added, and the mixture was distilled under reduced pressure at 40°C for 3 h. The mixture was extracted three times with dichloromethane (500 ml each time), the organic phases were combined, washed with 500 ml of deionized water, dried over 80 g of anhydrous sodium sulfate, filtered, and distilled under reduced pressure at 30°C for 3 h to obtain an isocyanate compound; its H NMR spectrum data are as follows: 1 H NMR (300 MHz, DMSO-d6) δ4.39-4.21 (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);

[0035] S3: Under nitrogen protection, 2000 ml of DMF, 230 g of isocyanate compound, and 100 g of polyethylene glycol (PEG-800) were added to the reactor in sequence, stirred and mixed, 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, which was filtered, washed with 800 ml of deionized water, and dried under vacuum at 50°C for 6 h to obtain the toughening agent.

[0036] Example 2 Preparation of toughening agent:

[0037] S1: In an ice-water bath, add 500 ml of methanol and 1 mol of ethylenediamine to a reaction kettle. Add 4.3 mol of hydroxyethyl methacrylate dropwise under nitrogen protection over 2 h. Warm the mixture to room temperature for 24 h. Distill under reduced pressure at 50°C for 3 h to obtain a light yellow liquid four-arm compound.

[0038] 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 reactor, 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 temperature was raised to room temperature for 4 h, 300 ml of ice water was added, and the mixture was distilled under reduced pressure at 40°C for 3 h. The mixture was extracted three times with dichloromethane (500 ml each time), the organic phases were combined, washed with 500 ml of deionized water, 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;

[0039] S3: Under nitrogen protection, 2000 ml of DMF, 250 g of isocyanate compound, and 100 g of polyethylene glycol (PEG-800) were added to the reactor in sequence, stirred and mixed, and 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, which was filtered, washed with 800 ml of deionized water, and dried under vacuum at 50°C for 6 h to obtain the toughening agent.

[0040] Example 3 Preparation of toughening agent:

[0041] S1: In an ice-water bath, add 500 ml of methanol and 1 mol of ethylenediamine to a reaction kettle. Add 4.5 mol of hydroxyethyl methacrylate dropwise under nitrogen protection over 2 h. Warm the mixture to room temperature for 26 h. Distill under reduced pressure at 50°C for 3 h to obtain a light yellow liquid four-arm compound.

[0042] 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 reactor, stirred at room temperature for 1 h, cooled to 0°C, and 100 ml of a THF solution containing 0.46 mol of 1-chloro-4-isocyanatobutane was added dropwise. The temperature was raised to room temperature for 5 h, 300 ml of ice water was added, and the mixture was distilled under reduced pressure at 40°C for 3 h. The mixture was extracted three times with dichloromethane (500 ml each time), the organic phases were combined, washed with 500 ml of deionized water, 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;

[0043] S3: Under nitrogen protection, 2000 ml of DMF, 260 g of isocyanate compound, and 100 g of polyethylene glycol (PEG-800) were added to the reactor in sequence, stirred and mixed, 10 g of dibutyltin dilaurate was added, the temperature was raised to 50°C, and the reaction was carried out for 6 h. 3000 ml of deionized water was added to precipitate the solid, which was filtered, washed with 800 ml of deionized water, and dried under vacuum at 50°C for 6 h to obtain the toughening agent.

[0044] Example 4 Preparation of modified hydroxyapatite:

[0045] N1: Stir 500 g of deionized water and 100 g of hydroxyapatite for 1 h, adjust the pH 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 (using 300 ml each time), and dry in a vacuum at 120°C for 12 h to obtain silane-modified apatite;

[0046] N2: Under nitrogen protection, 800 ml of DMF and 10 g of dopamine were placed in a reactor in sequence. The temperature was raised to 80°C, and 150 g of silane-modified apatite was added in batches (divided into 10 batches, with an interval of 10 min between each batch). The mixture was stirred and kept warm for 24 h. The temperature was then lowered to room temperature. The pH was adjusted to 3 using 1 M HCl solution, and the precipitate was precipitated. The precipitate was washed with deionized water (200 ml × 3 times) and dried in vacuo at 70°C for 10 h to obtain modified hydroxyapatite.

[0047] Example 5 Preparation of implantable absorbable PLA composite material:

[0048] (1) Weigh 600 g of PLA, 50 g of poly(lactide-co-glycolide), 80 g of polycaprolactone, 50 g of modified hydroxyapatite (prepared in Example 4), 20 g of toughening agent (prepared in Example 1), and 2 g of antioxidant (catechol);

[0049] (2) The above components were added to a high-speed mixer and mixed at a mixing temperature of 160°C, a mixing speed of 50 r / min, and a mixing time of 10 min. The mixture was then introduced into a twin-screw extruder for extrusion granulation. The screw speed of the screw extruder was 10 r / s, the conveying section temperature of the twin-screw extruder was 160°C, the melting section temperature was 170°C, the mixing section temperature was 175°C, and the homogenization section temperature was 160°C. The mixture was air-cooled and sieved to obtain an implantable absorbable PLA composite material.

[0050] Example 6 Preparation of implantable absorbable PLA composite material:

[0051] (1) Weigh 80 g of PLA, 80 g of poly(lactide-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);

[0052] (2) The above components were added to a high-speed mixer and mixed at a mixing temperature of 170°C, a mixing speed of 80 r / min, and a mixing time of 20 min. The mixture was then introduced into a twin-screw extruder for extrusion granulation. The screw speed of the screw extruder was 10 r / s, the conveying section temperature of the twin-screw extruder was 170°C, the melting section temperature was 180°C, the mixing section temperature was 185°C, and the homogenization section temperature was 170°C. The mixture was air-cooled and sieved to obtain an implantable absorbable PLA composite material.

[0053] Example 7 Preparation of implantable absorbable PLA composite material:

[0054] (1) Weigh 700 g of PLA, 100 g of poly(lactide-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);

[0055] (2) The above components were added to a high-speed mixer and mixed at a mixing temperature of 160°C, a mixing speed of 80 r / min, and a mixing time of 10 min. The mixture was then introduced into a twin-screw extruder for extrusion granulation. The screw speed of the screw extruder was 10 r / s, the conveying section temperature of the twin-screw extruder was 160°C, the melting section temperature was 170°C, the mixing section temperature was 175°C, and the homogenization section temperature was 160°C. The mixture was air-cooled and sieved to obtain an implantable absorbable PLA composite material.

[0056] Comparative Example 1

[0057] The raw material composition and process of the implantable absorbable PLA composite material are basically the same as those in Example 6, except that the toughening agent added to the component (prepared in Example 2) is replaced with an equal mass of isocyanate compound (prepared in step S2 of Example 2).

[0058] Comparative Example 2

[0059] The raw material composition and process of the implantable absorbable PLA composite material are basically the same as those in Example 6, except that the toughening agent added to the components (prepared in Example 2) is replaced with an equal mass of toughening agent prepared by the following method:

[0060] The preparation method of the toughening agent is basically the same as that of Example 2, except that the polyethylene glycol (PEG-800) in step S3 is replaced by polyethylene glycol (PEG-400) of the same weight.

[0061] Comparative Example 3

[0062] The raw material composition and process of the implantable absorbable PLA composite material are basically the same as those in Example 6, except that the toughening agent added to the components (prepared in Example 2) is replaced with a toughening agent of equal mass prepared by the following method:

[0063] The preparation method of the toughening agent is basically the same as that of Example 2, except that the polyethylene glycol (PEG-800) in step S3 is replaced by polyethylene glycol (PEG-10000) of the same weight.

[0064] Comparative Example 4

[0065] 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 to the components is replaced with unmodified hydroxyapatite of the same mass.

[0066] Comparative Example 5

[0067] The raw material composition and process of the implantable absorbable PLA composite material are basically the same as those in Example 6, except that the modified hydroxyapatite added to the components (prepared in Example 4) is replaced with an equal mass of silane-modified apatite (prepared in step N1 of Example 4).

[0068] Comparative Example 6

[0069] 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 to the components is replaced with an equal mass of modified hydroxyapatite prepared by the following method:

[0070] 500 g of deionized water and 100 g of hydroxyapatite were stirred for 1 h, the pH value was adjusted to 4.0 with acetic acid, 200 ml of a deionized water solution containing 10 g of dopamine was added, and the mixture was stirred at room temperature for 8 h. The mixture was filtered and washed three times with deionized water (300 ml each time), and vacuum dried at 120°C for 12 h to obtain silane-modified apatite.

[0071] Comparative Example 7

[0072] 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 to the components is replaced with an equal mass of modified hydroxyapatite prepared by the following method:

[0073] The preparation method of modified hydroxyapatite is basically the same as that of Example 4, except that the 3-glycidyloxypropyltrimethoxysilane in step N1 is replaced by an equal weight of [8-(epoxypropyloxy)-n-octyl]trimethoxysilane.

[0074] Comparative Example 8

[0075] 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 to the components is replaced with an equal mass of modified hydroxyapatite prepared by the following method:

[0076] The preparation method of modified hydroxyapatite is basically the same as that of Example 4, except that dopamine in step N2 is replaced by an equal weight of 4-amino-2-hydroxymethyl-1-butanol.

[0077] The model of PLA used in Examples 5-7 and Comparative Examples 1-8 of the present application is JHMS®PL25, with a molecular weight of 250,000, produced by Sichuan Zhuoxin Biomaterials Research Co., Ltd.; the models of poly(lactide-glycolide) and polycaprolactone are PLG75-10 and PCL-20, respectively, produced by Shenzhen Boli Biomaterials Co., Ltd.; the model of hydroxyapatite is HAP04-20, produced by Nanjing Junzhuo Biotechnology Co., Ltd.

[0078] 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.

[0079] The tensile strength and elongation at break were measured in accordance with GB / T 1040.2-2022 on dumbbell-shaped specimens with a thickness of 0.4 mm at a speed of 10 mm / min. The notched impact strength was measured in accordance with ASTM D256 with a pendulum mass of 0.668 kg, a speed of 0.46 m / s, and a pendulum energy of 4 J. The test results are shown in Table 1.

[0080] Table 1 Performance test data table

[0081] project Tensile strength MPa Elongation at break % <![CDATA[Izod 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

[0082] 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.

[0083] The carbamate in the toughening agent prepared by the present application can form hydrogen bonds with PLA molecules, which can enhance interfacial adhesion, enable the material to evenly transmit stress during stretching, and delay fracture; the introduction of flexible polyethylene glycol segments can improve the molecular entanglement and compatibility of PLA, poly(lactide-glycol) and polycaprolactone, and its high flexibility and freedom of movement can effectively disperse external stress and improve tensile properties. The unreacted isocyanate groups in the toughening agent can react with the hydroxyl groups of PLA during the melting process, further improving the interfacial bonding strength. In addition, the toughening agent prepared by the present application introduces a large amount of ester groups through hydroxyethyl methacrylate, which is beneficial to the degradation of the toughening agent. The flexible polyethylene glycol segment introduced in the plasticizer used in Comparative Example 2 is limited in length, and the effect of dispersing external stress by molecular chain slippage is limited, resulting in a decrease in the elongation at break of the material.

[0084] The modified hydroxyapatite prepared by the present 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, thereby improving its mechanical properties. The modified hydroxyapatite prepared by the present 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 is surface-modified only by dopamine. The benzene ring structure of dopamine is relatively rigid but not flexible enough, resulting in a decrease in the mechanical properties of the material. The modified hydroxyapatite used in Comparative Example 7 contains long-chain alkyl groups and has poor compatibility with the PLA matrix, thereby affecting the mechanical properties of the material.

[0085] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. However, any equivalent changes, modifications and evolutions made by ordinary technicians in this field without departing from the scope of the technical solution of the present invention by 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 are still within the scope of protection of the technical solution of the present invention.

Claims

1. An implantable absorbable PLA composite material, characterized in that: The composition comprises the following raw materials in parts by weight: PLA 60-70 parts, poly (lactide-glycol) 5-10 parts, polycaprolactone 8-12 parts, modified hydroxyapatite 5-8 parts, toughening agent 2-3 parts, antioxidant 0.2-0.6 parts; The toughening agent is prepared by the following method: S1: Hydroxyethyl methacrylate reacts with ethylenediamine in methanol solution to form a four-arm compound; S2: The four-arm compound reacts with 1-chloro-4-isocyanatobutane under alkaline conditions to obtain an isocyanate compound; S3: an isocyanate compound reacts with polyethylene glycol 800 in the presence of a catalyst, dibutyltin dilaurate, to obtain a toughening agent; The modified hydroxyapatite is prepared by the following method: N1: silane-modified apatite was generated by reaction of hydroxyapatite with 3-glycidoxypropyltrimethoxysilane; N2: Silane-modified apatite reacts with dopamine to form modified hydroxyapatite.

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

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

4. The implantable absorbable PLA composite material according to claim 1, characterized in that: The mass ratio of the isocyanate compound to the polyethylene glycol in step S3 is (2.3-2.6):

1.

5. The implantable absorbable PLA composite material according to claim 1, characterized in that: The mass ratio of hydroxyapatite to 3-glycidyloxypropyltrimethoxysilane in step N1 is 10:

1.

6. The implantable absorbable PLA composite material according to claim 1, characterized in that: The mass ratio of the silane-modified apatite to dopamine in step N2 is 15:

1.

7. The implantable absorbable PLA composite material according to claim 1, characterized in that: The antioxidant is catechol.

8. A method for preparing the implantable absorbable PLA composite material according to any one of claims 1 to 7, characterized in that: The following steps are involved: (1) Weigh by weight: 60-70 parts of PLA, 5-10 parts of poly(lactide-glycol) copolymer, 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) The above components are added into a high-speed mixer and mixed, and then the mixture is introduced into a twin-screw extruder for extrusion and granulation, and air-cooled and sieved to obtain an implantable absorbable PLA composite material.

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