Photo-thermal response type polyether-ether-ketone nanocomposite and preparation method thereof

Abstract

The invention discloses a photo-thermal response type polyether-ether-ketone nano composite material. A preparation method of the photo-thermal response type polyether-ether-ketone nano composite material comprises the following steps: 1) continuously reacting nano hydroxyapatite with dopamine hydrochloride in a stirring state to prepare polydopamine coated hydroxyapatite nano particles; 2) dispersing the polyether-ether-ketone micro powder and the polydopamine-coated hydroxyapatite nanoparticles in water, and carrying out preliminary blending, separation, freeze drying, drying, crushing and high-speed ball milling to obtain uniform composite powder; and 3) carrying out extrusion molding on the obtained composite powder to obtain the photo-thermal response type polyether-ether-ketone nano composite material. The preparation method comprises the following steps: firstly, preparing polydopamine-coated hydroxyapatite nano-particles by adopting an in-situ polymerization method, and preparing the photo-thermal response type polyether-ether-ketone and polydopamine-coated hydroxyapatite nano-particle composite material by combining processes such as ball-milling blending and melt extrusion, so that good mechanical properties, biocompatibility, photo-thermal response performance and the like can be considered; and the adaptability is wide.

Description

Technical Field

[0001] The present invention belongs to the technical field of biomedical materials, and in particular relates to a photothermal responsive polyetheretherketone nanocomposite material and a preparation method thereof. Background Art

[0002] Bone repair materials refer to materials that mimic the structure and function of natural bones and are used to repair or replace damaged bone tissue. Their purpose is to simulate the biological characteristics of human bones as much as possible. The development of bone repair materials with good mechanical properties and biocompatibility is an urgent and major need for tissue and organ repair in clinical medicine.

[0003] Polyetheretherketone material has an elastic modulus very close to that of human bone, and its excellent mechanical properties, biocompatibility and thermal stability make it stand out among many bone repair materials. However, single polyetheretherketone material is bioinert and has poor compatibility, which leads to poor integration with surrounding tissues after implantation. Hydroxyapatite is the main inorganic component of human bones and teeth, and has excellent biocompatibility; however, the poor toughness, low strength and high brittleness of hydroxyapatite limit its application as a bone implant. By introducing hydroxyapatite into polyetheretherketone material to prepare polyetheretherketone / hydroxyapatite nanocomposite materials, the advantages of the two materials can be combined and their respective deficiencies can be supplemented to form a better hard tissue medical implant material. However, the two phases of polyetheretherketone / hydroxyapatite composite materials are organic phase and inorganic phase, respectively, and the interface compatibility between the two phases is poor. How to improve the interface compatibility between the two phases of polyetheretherketone / hydroxyapatite composite materials and thus improve the performance of the material is still a difficult problem.

[0004] In addition, although the method of carrying exogenous biological agents helps to improve the bioactivity of polyetheretherketone implants, problems such as ectopic osteogenesis caused by inappropriate release behavior also limit its further clinical transformation. Further exploration of mild and safe stimulation mechanisms to promote bone regeneration is also of great research and application significance. Summary of the invention

[0005] The main purpose of the present invention is to provide a photothermal responsive polyetheretherketone nanocomposite material, in which the polyetheretherketone matrix is ​​modified by encapsulating hydroxyapatite with polydopamine, and the obtained nanocomposite material has good mechanical properties, biocompatibility, interface compatibility and photothermal responsiveness.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] A method for preparing a photothermal responsive polyetheretherketone nanocomposite material comprises the following steps:

[0008] 1) Under stirring conditions, add nano-hydroxyapatite into the buffer solution, ultrasonically disperse the obtained mixture, then add dopamine hydrochloride, continuously react under stirring conditions, perform centrifugal separation, and freeze-dry the obtained product to obtain hydroxyapatite nanoparticles wrapped with polydopamine;

[0009] 2) Disperse polyetheretherketone micropowder and hydroxyapatite nanoparticles wrapped with polydopamine in water, ultrasonically treat the obtained dispersion under stirring conditions, perform centrifugal separation, and freeze-dry the obtained product to obtain a composite powder of hydroxyapatite nanoparticles wrapped with polydopamine and polyetheretherketone; then further dry the obtained composite powder, grind and crush it, and then perform high-speed ball milling to obtain a uniform composite powder;

[0010] 3) Extrude the obtained composite powder to obtain the photothermal-responsive polyetheretherketone nanocomposite material.

[0011] In the above scheme, the nano-hydroxyapatite is needle-shaped or spherical-like, etc.

[0012] Further, the needle-shaped nano-hydroxyapatite has a length of 140 - 160 nm and a width of 15 - 20 nm; the particle size of the spherical-like nano-hydroxyapatite is 180 - 220 nm.

[0013] In the above scheme, the average particle size of the polyetheretherketone is 40 - 60 μm.

[0014] In the above scheme, the mass ratio of the nano-hydroxyapatite to dopamine hydrochloride is (3 - 10):1.

[0015] In the above scheme, the concentration of dopamine hydrochloride in the mixture is 0.002 - 0.006 g / ml.

[0016] In the above scheme, the buffer solution uses a Tris-HCl solution with a concentration of 8 - 13 mmol / L, preferably 10 mmol / L.

[0017] In the above scheme, both the nano-hydroxyapatite and dopamine hydrochloride are added to the Tris-HCl solution in powder form.

[0018] In the above scheme, the ultrasonic dispersion time in step 1) is 15 - 30 min, and after adding dopamine hydrochloride, continuous reaction is carried out under stirring at room temperature for 22 - 24 h.

[0019] In the above scheme, the freeze-drying temperature is -50 to -40 °C, and the time is 12 - 16 h.

[0020] In the above scheme, the mass ratio of the hydroxyapatite wrapped with polydopamine to polyetheretherketone is (1 - 5):10.

[0021] Further, in step 2), the concentration of polyetheretherketone in the obtained aqueous dispersion is 0.1 - 0.3 g / ml.

[0022] In the above solution, the ultrasonic time in step 2) is 15 - 30 min, the power is 40 - 60 Hz; the stirring rate is 400 - 800 rpm.

[0023] In the above solution, the drying temperature is 100 - 120 °C, and the time is 3 - 4 h.

[0024] In the above solution, the grinding should be carried out until the agglomerated powder is completely broken.

[0025] In the above solution, in the high-speed ball milling step, the mass ratio of the ball milling beads to the composite powder is (1 - 1.5):1, the ball milling time is 4 - 4.5 h, and the ball milling speed is 380 - 420 rpm.

[0026] In the above solution, in the extrusion molding step, a twin-screw extruder is used, and the set parameter conditions are: the main machine speed is 40 - 60 rpm, the feeding speed is 2 - 3 Hz, and the temperature of the material mixing zone is controlled at 330 - 370 °C, where the melting and mixing zone is set at 330 - 340 °C, and the die head is set at 360 - 370 °C, which can effectively ensure the composite effect.

[0027] The photothermal-responsive polyetheretherketone nanocomposite prepared according to the above solution includes a polyetheretherketone matrix material and hydroxyapatite wrapped with polydopamine uniformly dispersed therein. Its tensile strength can reach above 107 MPa, its compressive strength can reach above 245 MPa, some areas of the tensile fracture surface are relatively smooth and uniform, and almost no holes are generated; it can reach photothermal equilibrium within 7 min, and the photothermal response performance does not decrease significantly after 3 consecutive photothermal cycles.

[0028] The photothermal-responsive polyetheretherketone nanocomposite obtained by the present invention can be applied to the preparation of bone defect repair scaffolds, etc.

[0029] Further, when the photothermal-responsive polyetheretherketone nanocomposite is specifically applied, it is first cut into particles 2 - 3 mm long, and then a template is added for injection molding, and the molding temperature is 160 - 180 °C.

[0030] The present invention first prepares hydroxyapatite nanoparticles wrapped with polydopamine by in-situ polymerization method, and conducts ball milling and melt extrusion to prepare a photothermal-responsive polyetheretherketone / polydopamine-wrapped hydroxyapatite nanocomposite; the introduced polydopamine can effectively improve the interfacial compatibility between the polyetheretherketone organic phase and the hydroxyapatite inorganic reinforcing phase of the composite material, and can effectively improve the dispersion effect of hydroxyapatite in the polyetheretherketone matrix, effectively taking into account the mechanical properties, thermal stability and photothermal response performance of the obtained composite material.

[0031] The prepared polyetheretherketone / polydopamine-coated hydroxyapatite nanocomposite has good mechanical properties, photothermal response properties and biocompatibility, and is expected to become an ideal material for hard tissue repair.

[0032] Compared with the prior art, the beneficial effects of the present invention include:

[0033] 1) The present invention uses nano-hydroxyapatite, dopamine hydrochloride and polyetheretherketone as the main raw materials. First, nano-hydroxyapatite and dopamine hydrochloride are in-situ polymerized and compounded to prepare a polydopamine-coated hydroxyapatite nanocomposite, and then premixed and dispersed with polyetheretherketone, and combined with an optimized hot extrusion molding process to effectively improve the interfacial compatibility between polyetheretherketone and hydroxyapatite and the dispersion effect of hydroxyapatite in the polyetheretherketone matrix; effectively avoid problems such as stress concentration caused by the agglomeration effect of nano-hydroxyapatite particles;

[0034] 2) For the premix of the polyetheretherketone matrix material and polydopamine-coated hydroxyapatite, the present invention first performs freeze-drying and drying in sequence, and then performs crushing and ball milling, which can effectively improve the dispersion of polydopamine-coated hydroxyapatite nanoparticles in the polyetheretherketone matrix material and effectively inhibit agglomeration problems, etc.;

[0035] 3) The obtained polyetheretherketone / polydopamine-coated hydroxyapatite nanocomposite of the present invention has both good biocompatibility, mechanical properties and excellent photothermal response properties, and can be used in the fields of bone defect repair scaffolds and medical beauty, etc. Description of the Drawings

[0036] Figure 1 TEM images of the hydroxyapatite nanoparticles used in the examples and the obtained PZHA;

[0037] Figure 2 Mechanical property test results of PEEK, the obtained PZHA, PQHA, PZB, and PQB used in the examples, where (a) is the tensile strength, (b) is the flexural strength; (c) is the compressive strength; (d) is the surface hardness;

[0038] Figure 3 SEM morphology analysis results of the tensile fracture surfaces of PEEK, the obtained PZHA, PQHA, PZB, and PQB used in the examples;

[0039] Figure 4 TG and DSC analysis results of PEEK, the obtained PZHA, PQHA, PZB, and PQB used in the examples;

[0040] Figure 5Compatibility analysis results of PEEK, obtained PZHA, PQHA, PZB, and PQB for the examples;

[0041] Figure 6 Photothermal conversion performance analysis results of PEEK, obtained PZHA, PQHA, PZB, and PQB for the examples, where (a) is the overall photothermal response performance; (b) - (c) are the temperature increases of PZB and PQB within 15 min and at different power densities, respectively; (d) and (e) are the temperature changes of PZB and PQB composites under three consecutive cycles of laser ON (15 min) and OFF (15 min);

[0042] Figure 7 Photothermal conversion performance analysis results of PEEK, obtained PZHA, PQHA, PZB, and PQB under wet conditions, where (a) is the overall photothermal response performance; (b) is the temperature increase within 15 min under near-infrared light power density irradiation of 0.5 W / cm 2 ; (c) is the temperature change of PZB and PQB composites under three consecutive cycles of laser ON (0.5 W / cm 2 , 15 min) and OFF (15 min). Detailed implementation manners

[0043] To better understand the present invention, the content of the present invention will be further clarified below in conjunction with examples, but the content of the present invention is not limited to the following examples only.

[0044] In the following examples, the average length of the needle-like nano-hydroxyapatite used is 150 nm, and the average width is 20 nm; the average particle size of the spherical nano-hydroxyapatite is 200 nm.

[0045] The average particle size of the polyetheretherketone used is 50 μm.

[0046] Example 1

[0047] A photothermal-responsive polyetheretherketone nanocomposite, and its preparation method includes the following steps:

[0048] 1) Under stirring, add 30 g of nano-hydroxyapatite (needle-like) to 1000 ml of buffer solution (Tris-HCl solution, 10 mmol / L), ultrasonically disperse for 15 min, then add 3 g of hydrochloric acid dopamine to the dispersed solution, continuously react for 24 h under stirring, centrifuge (8000 rpm, centrifuge 8 times), and freeze-dry the obtained product for 12 h to obtain poly-dopamine-coated hydroxyapatite nanoparticles;

[0049] 2) Disperse 270 g of polyetheretherketone micropowder and 30 g of hydroxyapatite nanoparticles encapsulated with polydopamine in 1000 ml of water. Under stirring conditions (500 rpm), ultrasonicate the resulting dispersion solution (20 min, 50 Hz), perform centrifugal separation (8000 rpm, centrifuge 8 times), and freeze-dry the resulting solid product (-50 °C, 12 h) to obtain a composite powder of hydroxyapatite nanoparticles (needle-shaped) encapsulated with polydopamine and polyetheretherketone;

[0050] Further dry the obtained composite powder (100 °C, 3 h), grind it until the agglomerated powder is completely broken, and add the obtained composite powder to a planetary ball mill for high-speed ball milling and mixing; among them, the mass ratio of the powder to the milling beads is 1:1, ball mill and mix for 4 h, and the ball milling speed is 400 rpm to obtain a uniform composite powder;

[0051] 3) Pour the composite powder obtained in step 2) into a twin-screw extruder. Among them, the parameter conditions set for the twin-screw extruder are: the main machine speed is 60 r / min, the feeding speed is 2.3 Hz, and the temperature of the material mixing zone is controlled at 340 - 360 °C, where the melting and mixing zone is set at 340 °C and the die head is set at 360 °C; thus, a polyetheretherketone / polydopamine-encapsulated hydroxyapatite composite material (denoted as PZB) is obtained.

[0052] Example 2

[0053] A photothermal-responsive polyetheretherketone nanocomposite material, and its preparation method includes the following steps:

[0054] 1) Under stirring conditions, add 30 g of nano-hydroxyapatite (spherical-like) to 1000 ml of buffer solution (Tris-HCl solution, 10 mmol / L), ultrasonically disperse for 15 min, then add 3 g of dopamine hydrochloride to the dispersed solution, continuously react for 24 h under stirring conditions, perform centrifugal separation (8000 rpm, centrifuge 8 times), and freeze-dry the obtained product for 12 h to obtain hydroxyapatite nanoparticles encapsulated with polydopamine;

[0055] 2) Disperse 270 g of polyetheretherketone micropowder and 30 g of hydroxyapatite nanoparticles encapsulated with polydopamine in 1000 ml of water. Under stirring conditions (500 rpm), ultrasonicate the resulting dispersion solution (20 min, 50 Hz), perform centrifugal separation (8000 rpm, centrifuge 8 times), and freeze-dry the resulting solid product (-50 °C, 12 h) to obtain a composite powder of hydroxyapatite nanoparticles (spherical-like) encapsulated with polydopamine and polyetheretherketone;

[0056] The obtained composite powder was further dried (at 100 °C for 3 h), ground until the agglomerated powder was completely broken, and the obtained composite powder was added to a planetary ball mill for high-speed ball milling and mixing; wherein, the mass ratio of the powder to the milling beads was 1:1, ball milling and mixing was carried out for 4 h, and the ball milling speed was 400 rpm to obtain a uniform composite powder;

[0057] 3) Pour the composite powder obtained in step 2) into a twin-screw extruder. Among them, the parameter conditions set for the twin-screw extruder are: the main machine speed is 60 r / min, the feeding speed is 2.3 Hz, and the temperature of the material mixing zone is controlled at 340 - 360 °C, wherein the melting and mixing area is set at 340 °C and the head is set at 360 °C; thus, a polyether ether ketone / polydopamine-coated hydroxyapatite composite material (denoted as PQB) is obtained.

[0058] Example 3

[0059] A photothermal-responsive polyether ether ketone nanocomposite material, and its preparation method includes the following steps:

[0060] 1) Under stirring conditions, add 30 g of nano-hydroxyapatite (needle-shaped) to 1000 ml of buffer solution (Tris-HCl solution, 10 mmol / L), ultrasonically disperse for 15 min, then add 6 g of hydrochloric acid dopamine to the dispersed solution, and continuously react for 48 h under stirring conditions, centrifuge (8000 rpm, centrifuge 8 times), and freeze-dry the obtained product for 12 h to obtain polydopamine-coated hydroxyapatite nanoparticles;

[0061] 2) Disperse 270 g of polyether ether ketone fine powder and 30 g of polydopamine-coated hydroxyapatite nanoparticles in 1000 ml of water, ultrasonically treat the obtained dispersion solution under stirring conditions (500 rpm) (20 min, 50 Hz), centrifuge (8000 rpm, centrifuge 8 times), and freeze-dry the obtained solid product (-50 °C, 12 h) to obtain a composite powder of polydopamine-coated hydroxyapatite nanoparticles (needle-shaped) and polyether ether ketone;

[0062] The obtained composite powder was further dried (at 100 °C for 3 h), ground until the agglomerated powder was completely broken, and the obtained composite powder was added to a planetary ball mill for high-speed ball milling and mixing; wherein, the mass ratio of the powder to the milling beads was 1:1, ball milling and mixing was carried out for 4 h, and the ball milling speed was 400 rpm to obtain a uniform composite powder;

[0063] 3) Pour the composite powder obtained in step 2) into a twin-screw extruder. The parameter conditions set for the twin-screw extruder are as follows: the main machine speed is 60 r / min, the feeding speed is 2.3 Hz, the temperature of the material mixing zone is controlled at 340 - 360 °C, where the melting and mixing zone is set at 340 °C and the head is set at 360 °C; thus, a polyetheretherketone / polydopamine-coated hydroxyapatite composite material is obtained.

[0064] Example 4

[0065] A photothermal-responsive polyetheretherketone nanocomposite material, and its preparation method includes the following steps:

[0066] 1) Under stirring conditions, add 30 g of nano-hydroxyapatite (spherical-like) to 1000 ml of buffer solution (Tris-HCl solution, 10 mmol / L), ultrasonically disperse for 15 min, then add 6 g of hydrochloric acid dopamine to the dispersed solution, continuously react for 48 h under stirring conditions, perform centrifugal separation (8000 rpm, centrifuge 8 times), and freeze-dry the obtained product for 12 h to obtain polydopamine-coated hydroxyapatite nanoparticles.

[0067] 2) Disperse 270 g of polyetheretherketone fine powder and 30 g of polydopamine-coated hydroxyapatite nanoparticles in 1000 ml of water, ultrasonically treat the obtained dispersion solution under stirring conditions (500 rpm) (20 min, 50 Hz), perform centrifugal separation (8000 rpm, centrifuge 8 times), and freeze-dry the obtained solid product (-50 °C, 12 h) to obtain a composite powder of polydopamine-coated hydroxyapatite nanoparticles (spherical-like) and polyetheretherketone.

[0068] Further dry the obtained composite powder (100 °C, 3 h), grind it until the agglomerated powder is completely broken, and add the obtained composite powder to a planetary ball mill for high-speed ball milling and mixing; among them, the mass ratio of the powder to the ball milling beads is 1:1, ball mill and mix for 4 h, and the ball milling speed is 400 rpm to obtain a uniform composite powder.

[0069] 3) Pour the composite powder obtained in step 2) into a twin-screw extruder. The parameter conditions set for the twin-screw extruder are as follows: the main machine speed is 60 r / min, the feeding speed is 2.3 Hz, the temperature of the material mixing zone is controlled at 340 - 360 °C, where the melting and mixing zone is set at 340 °C and the head is set at 360 °C; thus, a polyetheretherketone / polydopamine-coated hydroxyapatite composite material is obtained.

[0070] Comparative Example 1

[0071] A polyetheretherketone material is prepared by using pure polyetheretherketone powder (without polydopamine-coated nano-hydroxyapatite) as the melt extrusion material and adopting the process conditions described in steps 2) and 3) of Example 1.

[0072] Comparative Example 2

[0073] A polyetheretherketone material / nano-hydroxyapatite composite material has a preparation method substantially the same as that of Example 1, except that: in step 1), hydrochloric acid dopamine and the corresponding continuous reaction are not introduced, and a mixed powder of polyetheretherketone and needle-shaped nano-hydroxyapatite (without polydopamine) is used as the melt extrusion material to prepare a polyetheretherketone / nano-hydroxyapatite (needle-shaped) composite material (denoted as PZHA).

[0074] Comparative Example 3

[0075] A polyetheretherketone material / nano-hydroxyapatite composite material has a preparation method substantially the same as that of Example 2, except that: in step 1), hydrochloric acid dopamine and the corresponding continuous reaction are not introduced, and a mixed powder of polyetheretherketone and spherical nano-hydroxyapatite (without polydopamine) is used as the melt extrusion material to prepare a polyetheretherketone / nano-hydroxyapatite (spherical) composite material (denoted as PQHA).

[0076] Comparative Example 4

[0077] A polyetheretherketone / polydopamine-coated hydroxyapatite composite material has a preparation method substantially the same as that of Example 1, except that: in step 2), the product after blending is not freeze-dried but directly dried, and the drying temperature is extended to 12 h.

[0078] Comparative Example 5

[0079] A polyetheretherketone / polydopamine-coated hydroxyapatite composite material has a preparation method substantially the same as that of Example 1, except that: in step 3), the temperatures of the die head and the melt mixing area are both set to 340 °C.

[0080] In the following characterization results, PEEK, PZHA, PQHA, PZB, and PQB respectively represent polyetheretherketone, polyetheretherketone / hydroxyapatite (needle-shaped) nanocomposite material, polyetheretherketone / hydroxyapatite (spherical) nanocomposite material, polyetheretherketone / polydopamine-coated hydroxyapatite (needle-shaped) nanocomposite material, and polyetheretherketone / polydopamine-coated hydroxyapatite (spherical) nanocomposite material.

[0081] Perform TEM analysis on polydopamine-coated hydroxyapatite nanoparticles (b) and compare it with unmodified hydroxyapatite nanoparticles (a) to characterize the coating situation of polydopamine on nano-hydroxyapatite. By Figure 1Comparing (a) with (b), it can be seen that the surface of the nano-hydroxyapatite particles is coated with a poly-dopamine coating with a relatively light contrast.

[0082] Mechanical property analysis was carried out on polyetheretherketone / poly-dopamine-coated hydroxyapatite (needle-like) nanocomposites and polyetheretherketone / poly-dopamine-coated hydroxyapatite (spherical-like) nanocomposites, and they were compared with pure polyetheretherketone materials, polyetheretherketone / hydroxyapatite (needle-like) nanocomposites, and polyetheretherketone / hydroxyapatite (spherical-like) nanocomposites. The test results are as Figure 2 (a)–(d) shown. From Figure 2 (a), it can be seen that after poly-dopamine coating, the tensile strength of the two nano-composites with different hydroxyapatite morphologies has been significantly improved. Among them, the tensile strength of the polyetheretherketone / poly-dopamine-coated hydroxyapatite (needle-like) nanocomposite is 108.1 ± 0.3 MPa, which is 4.3% higher than that without coating; the tensile strength of the polyetheretherketone / poly-dopamine-coated hydroxyapatite (spherical-like) nanocomposite is 108.5 ± 0.7 MPa, which is 12.1% higher than that without coating. From Figure 2 (b), it can be seen that the flexural strength of the nano-composite after poly-dopamine coating has increased compared with that without coating. From Figure 2 (c), it can be seen that the compressive strength of the polyetheretherketone / poly-dopamine-coated hydroxyapatite (needle-like) nanocomposite is 272.2 ± 10.8 MPa, which is 39.4% higher than that without coating; the compressive strength of the polyetheretherketone / poly-dopamine-coated hydroxyapatite (spherical-like) nanocomposite is 266.0 ± 19.5 MPa, which is 49.4% higher than that without coating. From Figure 2 (d), it can be seen that the surface hardness of the nano-composite after poly-dopamine coating has also increased. From the data of tensile strength, flexural strength and modulus, compressive strength and surface hardness, it can be seen that the introduction of poly-dopamine can improve the mechanical properties of the nano-composite.

[0083] SEM morphology analysis was carried out on the tensile fracture surfaces of polyetheretherketone / poly-dopamine-coated hydroxyapatite (needle-like) nanocomposites and polyetheretherketone / poly-dopamine-coated hydroxyapatite (spherical-like) nanocomposites, and they were compared with pure polyetheretherketone materials, polyetheretherketone / hydroxyapatite (needle-like) nanocomposites, and polyetheretherketone / hydroxyapatite (spherical-like) nanocomposites. The test results are as Figure 3 shown. From Figure 3It can be seen that some regions of the tensile fracture surface of the polyetheretherketone material are relatively smooth and uniform, and almost no holes are generated. Some regions are rapid fracture zones, and the fracture surface shows an irregular and non-uniform lamellar structure. After the addition of hydroxyapatite, there are many holes on the surface of the composite material formed by the pulling out of nano-hydroxyapatite, and there are many aggregates on the fracture surface, indicating that the interfacial bonding ability between polyetheretherketone and nano-hydroxyapatite is insufficient and the interfacial interaction is weak. After the composite of polydopamine, the holes are significantly reduced and the crack propagation is more stable, indicating that the coating modification of polydopamine improves the interfacial compatibility between the organic matrix and the inorganic nano-reinforcing phase in the composite material, which is beneficial to improving the mechanical properties of the obtained composite material.

[0084] TG and DSC analyses were carried out on polyetheretherketone / polydopamine-coated hydroxyapatite (needle-shaped) nanocomposites and polyetheretherketone / polydopamine-coated hydroxyapatite (spherical-like) nanocomposites, and they were compared with pure polyetheretherketone materials, polyetheretherketone / hydroxyapatite (needle-shaped) nanocomposites and polyetheretherketone / hydroxyapatite (spherical-like) nanocomposites. The test results are as Figure 4 (a)-(d) shown.

[0085] From Figure 4 (a)-(b), it can be seen that in the TG curve, the mass loss of the coated composite material is less than that before coating and pure polyetheretherketone, which indicates that the coating of polydopamine can improve the thermal stability of the nanocomposite material. Through the DTG curve, it can be seen that the highest decomposition rate of the coated nanocomposite material is lower than that before coating, which verifies the conclusion drawn from the TG curve. From Figure 4 (c)-(d), it can be seen that from the heating curve, the melting point of the polyetheretherketone / hydroxyapatite nanocomposite material is 342 °C, and the melting point after coating is increased by 1-2 °C compared with that before coating. From the cooling curve, it can be seen that the crystallization temperature of the coated nanocomposite material is lower than that before coating, decreasing from 302.5 °C of pure polyetheretherketone to 299.4 °C of polyetheretherketone / polydopamine-coated hydroxyapatite (needle-shaped) nanocomposite and 298.2 °C of polyetheretherketone / polydopamine-coated hydroxyapatite (spherical-like) nanocomposite. This shows that polydopamine affects the crystallization temperature of the composite material by improving the distribution of nano-hydroxyapatite and the interfacial bonding between the organic and inorganic phases.

[0086] In vitro biocompatibility analyses were carried out on polyetheretherketone / polydopamine-coated hydroxyapatite (needle-shaped) nanocomposites and polyetheretherketone / polydopamine-coated hydroxyapatite (spherical-like) nanocomposites, and they were compared with the pure polyetheretherketone material in Comparative Example 1, the polyetheretherketone / hydroxyapatite (needle-shaped) nanocomposite in Comparative Example 2 and the polyetheretherketone / hydroxyapatite (spherical-like) nanocomposite in Comparative Example 3. The test results are asFigure 5 as shown

[0087] As can be seen Figure 5 from Figure 5 , as the culture time extended, the cells on the surface of the two groups of nano - composites after polydopamine coating proliferated more significantly than those on the surface of the nano - composites without coating, proving that the composites are non - toxic to cells and have good biocompatibility.

[0088] The photothermal conversion performance of polyetheretherketone / polydopamine - coated hydroxyapatite (needle - shaped) nano - composites and polyetheretherketone / polydopamine - coated hydroxyapatite (spherical - like) nano - composites under dry conditions was analyzed, and they were compared with pure polyetheretherketone materials, polyetheretherketone / hydroxyapatite (needle - shaped) nano - composites and polyetheretherketone / hydroxyapatite (spherical - like) nano - composites. The test results are as Figure 6 shown

[0089] As can be seen Figure 6 (a) that after 15 min of irradiation with NIR lasers of different power densities, the photothermal response performance of the materials highly depends on the power density of the NIR laser, and the temperature rises more significantly under the irradiation of lasers with higher power densities. The photothermal response performance of the two groups of composites after polydopamine coating has been significantly improved. For the power density of 0.5 W / cm 2 , the maximum stable temperature of the needle - shaped group of composites increased by 21.8 °C after coating compared with that without coating, while the spherical - like group increased by 24 °C. Figure 6 (b) and (c) respectively show the temperature rise of PZB and PQB within 15 min and at different power densities. For PZB, at the power densities of 0.2, 0.5, 0.8 W / cm 2 , the final stable temperatures are 70.9, 120.3, 173.2 °C respectively, while the final stable temperatures of PQB are 70.7, 123.8, 171.7 °C respectively. Under all conditions, the two polyetheretherketone / polydopamine - coated hydroxyapatite nano - composites can almost reach photothermal equilibrium within 7 min, showing fast and excellent photothermal response performance. Subsequently, Figure 6 (d) and (e) record the temperature changes of PZB and PQB composites under three consecutive laser ON (15 min) and OFF (15 min) cycles. The results show that the photothermal response performance of the two groups of composites does not decrease significantly after 3 consecutive photothermal cycles, indicating that the coated composites can withstand periodic NIR irradiation and have good photothermal cycle stability.

[0090] Photothermal conversion performance analysis of polyetheretherketone / polydopamine-coated hydroxyapatite (needle-shaped) nanocomposites and polyetheretherketone / polydopamine-coated hydroxyapatite (spheroid-like) nanocomposites was carried out under wet conditions, and they were compared with pure polyetheretherketone materials, polyetheretherketone / hydroxyapatite (needle-shaped) nanocomposites and polyetheretherketone / hydroxyapatite (spheroid-like) nanocomposites. The test results are as Figure 7 shown.

[0091] As Figure 7 (a) shows, under wet conditions, the photothermal response performance of the materials also highly depends on the power density of the NIR laser, and the temperature rises more significantly under the irradiation of a laser with a higher power density. As the laser power density increases, the temperature rise difference (ΔT) of the photothermal response performance of the composite materials also gradually increases. Taking a power density of 0.5 W / cm 2 as an example, the final stable temperatures of the PZB and PQB groups were 45.1 °C and 44.3 °C respectively, and the temperatures increased by 8.9 °C and 7.8 °C respectively compared with those without coating. This shows that the composite materials after polydopamine coating also have excellent photothermal response performance under wet conditions. Figure 7 (b) shows the temperature rise of five groups of materials within 15 min under the irradiation of a near-infrared light power density of 0.5 W / cm 2 . Among them, the two coated composite materials still showed the best photothermal conversion performance. The final temperatures of the needle-shaped group and the spheroid-like group were 44.3 °C and 44 °C respectively, and the ΔT was 24.2 °C and 23.4 °C. This temperature meets the requirements for promoting bone tissue regeneration under mild thermal stimulation. In contrast, the ΔT of the two uncoated groups were 15.3 °C and 15.6 °C respectively. Figure 7 (c) records the temperature changes of the PZB and PQB composite materials under three consecutive laser ON (0.5 W / cm 2 , 15 min) and OFF (15 min) cycles. The results show that the photothermal response performance of the two composite materials did not significantly weaken after three consecutive photothermal cycles, indicating that the composite materials after polydopamine coating can withstand periodic NIR irradiation after implantation and have good photothermal cycle stability.

[0092] Comparing the products of Example 1 and Comparative Example 4, the results show that there are holes formed due to the pulling out of some nano-hydroxyapatite on the tensile fracture surface of the composite material obtained in Comparative Example 4, and there are some aggregates on the fracture surface.

[0093] Comparing Example 2 and Comparative Example 5, it was found that during the extrusion process of Comparative Example 5, the fluidity of the material at the head part decreased, resulting in a slower extrusion speed and a faster cooling speed of the material, and finally leading to poorer mechanical properties of the material.

[0094] Obviously, the above embodiments are merely examples for clear illustration and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or alterations can be made based on the above description. It is not necessary and impossible to enumerate all implementation manners here. Thus, the obvious changes or alterations derived therefrom are still within the protection scope of the present invention.

Claims

1. A preparation method of a photothermal-responsive polyetheretherketone nanocomposite, characterized in that It includes the following steps: 1) Under stirring, add nano-hydroxyapatite into the buffer solution, ultrasonically disperse the obtained mixture, then add dopamine hydrochloride, continuously react under stirring, centrifuge and separate, and freeze-dry the obtained product to obtain hydroxyapatite nanoparticles wrapped with polydopamine; 2) Disperse polyetheretherketone micropowder and hydroxyapatite nanoparticles wrapped with polydopamine in water, ultrasonically treat the obtained dispersion under stirring conditions, centrifuge and separate, and freeze-dry the obtained product to obtain a composite powder of hydroxyapatite nanoparticles wrapped with polydopamine and polyetheretherketone; then further dry the obtained composite powder, grind and crush it, and then perform high-speed ball milling to obtain a uniform composite powder; 3) Extrusion-mold the obtained composite powder to obtain the photothermal-responsive polyetheretherketone nanocomposite material.

2. The preparation method according to claim 1, characterized in that, The nano-hydroxyapatite is needle-shaped or spherical-like; the needle-shaped nano-hydroxyapatite has a length of 140 - 160 nm and a width of 15 - 20 nm; the particle size of the spherical-like nano-hydroxyapatite is 180 - 220 nm.

3. The preparation method according to claim 1, characterized in that, The average particle size of the polyetheretherketone is 40 - 60 μm.

4. The preparation method according to claim 1, wherein The mass ratio of the nano-hydroxyapatite to dopamine hydrochloride is (3 - 10):

1.

5. The preparation method according to claim 1, characterized in that, The continuous reaction time is 22 - 24 h.

6. The preparation method according to claim 1, characterized in that The freeze-drying temperature is -50 to -40 °C, and the time is 12 - 16 h.

7. The preparation method according to claim 1, characterized in that, The mass ratio of the hydroxyapatite wrapped with polydopamine to polyetheretherketone is (1 - 5):

10.

8. The preparation method according to claim 1, characterized in that In the high-speed ball milling step, the mass ratio of the ball milling beads to the composite powder is (1 - 1.5):1, the ball milling time is 4 - 4.5 h, and the ball milling speed is 380 - 420 rpm.

9. The preparation method according to claim 1, characterized in that, In the extrusion molding step, a twin-screw extruder is used, and the set parameter conditions are: the main machine speed is 40 - 60 rpm, the feeding speed is 2 - 3 Hz, and the temperature of the material mixing area is controlled at 330 - 370 °C, wherein the melting and mixing area is set at 330 - 340 °C, and the head is set at 360 - 370 °C.

10. A photothermal-responsive polyetheretherketone nanocomposite material prepared by the preparation method according to any one of claims 1 to 9.

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