PEEK bone implant material of piezoelectric catalytic biological heterojunction and preparation method of PEEK bone implant material

Abstract

The invention belongs to the technical field of biological materials, and discloses a PEEK bone implant material of a piezoelectric catalysis biological heterojunction and a preparation method of the PEEK bone implant material, the material comprises a PEEK bone implant loaded with the biological heterojunction, the biological heterojunction is composed of BiVOO and a chalcogenide calcium compound in a molar ratio of 1-3, and the chalcogenide calcium compound is calcium sulfide, calcium selenide or calcium telluride; during preparation, the BiVO / CaX biological heterojunction is firstly prepared by a hydrothermal method or an in-situ composite method, then PEEK is sequentially subjected to acetone, ethanol and deionized water cleaning, sulfuric acid ultrasonic treatment for 5-10 minutes and dopamine modification, the biological heterojunction is in contact with the modified PEEK at 4 DEG C for 12 hours to complete loading, and improvement means can be introduced into part of schemes. The material has the acoustic catalytic antibacterial function and the bone repair promoting function, the antibacterial effect can be regulated and controlled through ultrasound, the process is simple, and the reaction condition is mild; the multi-drug-resistant bacterial infection can be dealt with, and the heterojunction loading stability and the material cell compatibility are improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of biological materials, and particularly relates to a PEEK bone implant material with piezoelectric catalytic biological heterojunction and a preparation method. BACKGROUND

[0002] At present, infectious diseases related to bacteria are a serious risk faced by human beings. In the process of combining with in-vivo tissues, infection caused by bacteria is one of the most common and most serious complications. The implant material in bone tissue needs to be kept in the body for a long time, and therefore the consequences caused by the problem of implant body related infection are more serious. Implant body failure caused after infection needs to be replaced, which increases the risk of secondary surgery for patients.

[0003] In clinical practice, the most commonly used anti-infection means at present is still antibiotics. However, long-term misuse and abuse of preventive antibiotics not only produces strong toxic side effects on normal cells and organs, but also leads to the prevalence of multi-drug resistant pathogens. Therefore, it is necessary to develop a bone implant material which can not only effectively eradicate microbial pathogens and promote bone repair but also does not produce bacterial resistance.

[0004] In the prior art, a plurality of polyether ether ketone-based bone implant materials have been disclosed. However, these materials mainly use near-infrared light to excite photocatalysis and photothermal therapy. At present, there is no bone implant material formed by combining a biological heterojunction with a PEEK matrix and having sound catalytic antibacterial and bone repair promoting properties disclosed. SUMMARY

[0005] In order to solve the problems existing in the prior art, the application provides a new PEEK bone implant material with piezoelectric catalytic biological heterojunction and a preparation method, which is different from the existing materials and realizes the corresponding technical effects through special piezoelectric properties.

[0006] The technical scheme adopted by the application is as follows: In a first aspect, the application provides a PEEK bone implant material with piezoelectric catalytic biological heterojunction, which comprises a PEEK bone implant loaded with a biological heterojunction material, and the biological heterojunction material is composed of BiVO4 and a sulfur family calcium compound in a molar ratio range of 1-3.

[0007] In combination with the first aspect, the application provides a first embodiment of the first aspect, wherein the biological heterojunction material is composed of BiVO4 and a sulfur family calcium compound in a molar ratio of 2:1.

[0008] In combination with the first aspect, the application provides a second embodiment of the first aspect, wherein the sulfur family calcium compound comprises one of calcium sulfide, calcium selenide and calcium telluride.

[0009] Secondly, the present invention also provides a preparation method for preparing the PEEK bone implant material with piezoelectric catalytic bioheterostructure mentioned above, as follows: First, a bio-heterogeneous material is prepared by adding chalcogenide calcium compounds to a BiVO4 mixed solution containing ethylene glycol to form a reaction solution. Then, a liquid system containing the bio-heterogeneous material is formed by hydrothermal method or in-situ composite method. After washing the liquid system alternately with anhydrous ethanol and deionized water and drying, BiVO4 / CaX bio-heterogeneous material is obtained. The obtained BiVO4 / CaX bio-heterogeneous material is loaded onto PEEK material to form a bone implant material.

[0010] In conjunction with the second aspect, the present invention provides a first embodiment of the second aspect, wherein the BiVO4 mixed solution is prepared by dissolving anhydrous bismuth nitrate and ammonium vanadate materials in a mixed solution of ethylene glycol and deionized water through ultrasonic treatment.

[0011] In conjunction with the second aspect, the present invention provides a second embodiment of the second aspect, wherein when preparing the bone implant material, the PEEK material is first cleaned with acetone, ethanol and deionized water, and then subjected to ultrasonic treatment with sulfuric acid for 5-10 minutes to obtain the treated sulfonated PEEK material. Prepare a 10 mmol / L Tris solution, adjust the pH of the Tris solution to 8.5 with dilute hydrochloric acid, and then add 2 mg / mL of dopamine hydrochloride to the Tris solution to obtain a dopamine solution. Sulfonated PEEK material was reacted with dopamine solution for 24 hours and then dried to obtain dopamine-modified PEEK material. The obtained BiVO4 / CaX bioheterostructure was fully contacted with dopamine-modified PEEK material at 4℃ for 12 hours to obtain bone implant material.

[0012] In conjunction with the second aspect, the present invention provides a third embodiment of the second aspect, wherein when forming a liquid system containing biological heterostructures using a hydrothermal method or an in-situ composite method, the heating temperature is 160°C and the holding time is at least 6 hours.

[0013] BiVO4 is a common semiconductor material in the prior art, while CaX can be introduced to form a heterojunction. However, conventional techniques are based on the characteristics of semiconductor materials and use photo-activated catalysis to enable the material to function at a specific location.

[0014] Specifically, conventional solutions often use external light sources such as near-infrared light and visible light as energy input. The light excites the BiVO4 / CaX heterojunction to generate photogenerated electron-hole pairs. The photogenerated carriers then react with water and oxygen in the surrounding environment to generate reactive oxygen free radicals, thus achieving the antibacterial effect. Some solutions also combine the photothermal conversion characteristics of BiVO4 to enhance the antibacterial effect by inducing local heating through light.

[0015] Ultrasound has excellent penetration depth and propagation stability in human tissues, and can easily reach deep bone implantation sites. By exciting heterojunctions with ultrasonic vibration energy to generate piezoelectric current and piezoelectric field, it drives the efficient generation of reactive oxygen free radicals, achieving acoustic catalytic antibacterial effects. At the same time, the calcium ions released by CaX and the piezoelectric effect can synergistically promote osteoblast adhesion, proliferation and differentiation, with both antibacterial and bone repair functions. This not only solves the efficiency shortcomings of conventional photoactivation technology in deep bone implantation scenarios, but also eliminates the dependence on external light sources, significantly improving the clinical applicability and reliability of bone implant materials.

[0016] The beneficial effects of this invention are as follows: 1. This invention provides a material that combines bone repair and acoustic catalytic antibacterial properties, thus increasing the variety of bone implant materials. Using this material can achieve bone regeneration and postoperative infection control. 2. The scaffold material prepared by the specific method used in this invention is loaded with biological heterostructures. Experiments show that the biological heterostructures have excellent acoustic catalytic antibacterial effects, thus providing an acoustic-dynamic antibacterial therapy method. 3. The method of the present invention is simple, the reaction conditions are mild, the energy consumption is low, and it is easy to mass-produce, thus it is conducive to promotion and application. Detailed Implementation

[0017] The present invention will be further explained below with reference to specific embodiments.

[0018] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the embodiments of this application. Obviously, the described embodiments are some embodiments of this application, but not all embodiments.

[0019] Therefore, the following detailed description of the embodiments provided in this application is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0020] Example 1: This embodiment discloses a piezoelectrically catalytic bioheterojunction PEEK bone implant material, the core of which is a PEEK matrix loaded with bioheterojunctions. The bioheterojunction material is composed of BiVO4 and chalcogenides in a molar ratio of 1:1 to 3:1, wherein the chalcogenides are one or more mixtures of CaS, CaSe, and CaTe, and the loading amount of the bioheterojunctions on the PEEK surface is 5-20 wt% based on the mass of the PEEK matrix.

[0021] This embodiment provides a method for manufacturing the above-mentioned materials, as detailed below: Preparation of bioheterojunctions: Anhydrous bismuth nitrate and ammonium vanadate are dissolved in a mixed solution of ethylene glycol and deionized water in stoichiometric ratio, and ultrasonically treated for 10-30 min until completely dissolved to obtain a BiVO4 precursor solution; a stoichiometric ratio of chalcogenide is added to the solution, and ultrasonically mixed for 15-40 min to form a homogeneous reaction solution. The reaction solution was transferred into a reaction vessel and kept at 140-180℃ for 6-12 hours using a hydrothermal method or an in-situ composite method to form a liquid system containing bio-heterojunctions. The system was then washed 3-5 times by alternating centrifugation with anhydrous ethanol and deionized water, each centrifugation speed of 8000-12000 r / min for 10-20 min to remove impurity ions. After that, the system was vacuum dried at 60-80℃ for 8-12 hours to obtain BiVO4 / CaX bio-heterojunction powder.

[0022] PEEK matrix pretreatment: Cut the PEEK material to the required size, and ultrasonically clean it with acetone, ethanol and deionized water for 15-30 minutes each to remove surface oil. Then immerse it in sulfuric acid with a concentration of 90-98wt% and ultrasonically treat it for 5-10 minutes. After taking it out, rinse it with a large amount of deionized water until the pH of the washing solution is neutral to obtain sulfonated PEEK material with a porous surface.

[0023] Dopamine modification: Prepare a 10 mmol / L Tris solution, adjust the pH to 8.5 with dilute hydrochloric acid, add dopamine hydrochloride to achieve a concentration of 2 mg / mL, and stir well to obtain a dopamine solution; immerse the sulfonated PEEK material in the dopamine solution and react at a constant temperature of 25-37℃ for 20-24 h, remove it and rinse the surface with deionized water to remove residual solution, and vacuum dry at 60℃ for 6-8 h to obtain dopamine-modified PEEK material.

[0024] Biological heterostructure loading: BiVO4 / CaX biological heterostructure powder was dispersed in deionized water and ultrasonically dispersed for 20-30 min to form a suspension with a concentration of 1-5 mg / mL; dopamine-modified PEEK material was immersed in the suspension and allowed to stand at 4-10℃ for 10-12 h, so that the biological heterostructure was loaded onto the PEEK surface through the adhesion of dopamine; after removal, it was vacuum dried at 60-70℃ for 6-10 h to obtain the biological heterostructure PEEK bone implant material.

[0025] Example 2: This embodiment is based on the material of Embodiment 1 above, and is limited to a BiVO4:CaS=1:1 bio-heterogeneous PEEK bone implant material, and the preparation method is as follows: Preparation of bio-heterojunctions: Weigh 0.01 mol of anhydrous bismuth nitrate and 0.01 mol of ammonium vanadate, dissolve them in a mixed solution of 50 mL of ethylene glycol and 50 mL of deionized water, and sonicate for 20 min to dissolve; add 0.01 mol of CaS powder, and sonicate for 30 min to form a reaction solution; transfer the reaction solution into a polytetrafluoroethylene reactor and hydrothermally incubate at 160 °C for 8 h; after the reaction is completed, wash the mixture 4 times by alternating centrifugation with anhydrous ethanol and deionized water (10000 r / min, 15 min / time), and vacuum dry at 70 °C for 10 h to obtain BiVO4 / CaS bio-heterojunctions (molar ratio 1:1).

[0026] PEEK pretreatment: PEEK material was ultrasonicated with acetone, ethanol and deionized water for 20 min each in sequence, immersed in 98wt% sulfuric acid and ultrasonicated for 6 min, and washed with water until neutral.

[0027] Dopamine modification: A dopamine solution was prepared according to the method in Example 1. After immersion in sulfonated PEEK, the solution was reacted at 37°C for 24 hours and then dried under vacuum at 60°C for 7 hours.

[0028] Loading: BiVO4 / CaS powder was dispersed into a 3 mg / mL suspension, dopamine-modified PEEK was impregnated and allowed to stand at 4 °C for 12 h, and then vacuum dried at 65 °C for 8 h to obtain the target material (loading 10 wt%).

[0029] Example 3: This embodiment is based on the material of Embodiment 1 above, and is limited to a biological heterostructure PEEK bone implant material with BiVO4:CaSe=2:1. The preparation method is as follows: Preparation of bio-heterojunctions: Weigh 0.02 mol of anhydrous bismuth nitrate and 0.02 mol of ammonium vanadate, dissolve them in a mixed solution of 80 mL of ethylene glycol and 40 mL of deionized water, and sonicate for 15 min to dissolve; add 0.01 mol of CaSe powder, and sonicate for 25 min to form a reaction solution; in situ composite at 160℃ for 7 h; wash the reaction solution 5 times by alternating centrifugation with anhydrous ethanol and deionized water, and vacuum dry at 65℃ for 9 h to obtain BiVO4 / CaSe bio-heterojunctions.

[0030] PEEK pretreatment: PEEK was ultrasonicated with acetone, ethanol and deionized water for 25 min each in sequence, then immersed in 95wt% sulfuric acid and ultrasonicated for 8 min, and washed with water until neutral.

[0031] Dopamine modification: Dopamine solution was prepared according to the method in Example 1, sulfonated PEEK was immersed in the solution and reacted at 30°C for 22 h, and then vacuum dried at 60°C for 6 h.

[0032] Loading: BiVO4 / CaSe powder was dispersed into a 4 mg / mL suspension, dopamine-modified PEEK was immersed in it, and the mixture was allowed to stand at 6 °C for 11 h, followed by vacuum drying at 70 °C for 7 h to obtain the target material.

[0033] Example 4: This embodiment is based on the material of Embodiment 1 above, and is limited to a BiVO4:CaTe=3:1 bio-heterogeneous PEEK bone implant material, and the preparation method is as follows: Preparation of bio-heterojunctions: Weigh 0.03 mol of anhydrous bismuth nitrate and 0.03 mol of ammonium vanadate, dissolve them in a mixed solution of 100 mL of ethylene glycol and 50 mL of deionized water, and sonicate for 25 min to dissolve; add 0.01 mol of CaTe powder, sonicate for 35 min to form a reaction solution; keep the solution at 170℃ hydrothermally for 10 h; wash the reaction solution four times by alternating centrifugation with anhydrous ethanol and deionized water, and vacuum dry at 75℃ for 8 h to obtain BiVO4 / CaTe bio-heterojunctions.

[0034] PEEK pretreatment: PEEK was ultrasonicated with acetone, ethanol and deionized water for 18 min each in sequence, then immersed in 92wt% sulfuric acid and ultrasonicated for 10 min, and washed with water until neutral.

[0035] Dopamine modification: Dopamine solution was prepared according to the method in Example 1, sulfonated PEEK was immersed in the solution and reacted at 28°C for 23 h, and then vacuum dried at 60°C for 8 h.

[0036] Loading: BiVO4 / CaTe powder was dispersed into a 2 mg / mL suspension, dopamine-modified PEEK was immersed in it, and the mixture was allowed to stand at 8°C for 10 h, followed by vacuum drying at 60°C for 9 h to obtain the target material.

[0037] Example 5: This embodiment is based on the material of Embodiment 1 above, and introduces hydroxyapatite to improve load stability and bone-promoting effect. Because existing heterojunction materials are prone to detach from the PEEK matrix in the body fluid environment, resulting in a decrease in piezoelectric antibacterial effect, and bone repair relies solely on calcium release from chalcogenides, the effect is limited.

[0038] Material composition The bioheterogeneous structure is composed of BiVO4:CaS=2:1 and 5wt% hydroxyapatite, loaded onto a PEEK matrix with a loading of 15wt%.

[0039] Preparation method Preparation of biological heterojunctions: BiVO4 / CaS heterojunction powder was prepared according to the method in Example 3. 5 wt% HA powder was added to the powder and ultrasonically dispersed for 30 min to obtain BiVO4 / CaS / HA composite heterojunctions.

[0040] The PEEK pretreatment and dopamine modification steps are the same as in Example 3.

[0041] Loading: BiVO4 / CaS / HA composite heterojunction was dispersed into a 4 mg / mL suspension, dopamine-modified PEEK was immersed in it, and then allowed to stand at 4℃ for 12 h, followed by vacuum drying at 70℃ for 8 h to obtain the target material.

[0042] Example 6: This embodiment is based on the material of Embodiment 1 above, and the annealing treatment enhances the low-power piezoelectric response. Existing similar materials require a high ultrasonic power ≥1.0W / cm² to achieve an effective piezoelectric antibacterial effect. High-power ultrasound may cause some damage to the surrounding normal bone tissue, making it difficult to meet the clinical need for low damage.

[0043] Material composition The bio-heterojunction is BiVO4:CaSe=2:1, and its crystal structure is optimized by annealing. It is loaded onto a PEEK matrix with a loading of 12wt%.

[0044] Preparation method Preparation of biological heterojunctions: BiVO4 / CaSe heterojunction powder was prepared according to the method in Example 3, and placed in a muffle furnace and annealed in air at 500°C for 2 hours. After natural cooling to room temperature, annealed BiVO4 / CaSe heterojunctions were obtained.

[0045] The PEEK pretreatment and dopamine modification steps are the same as in Example 3.

[0046] Loading: The annealed BiVO4 / CaSe heterojunction was dispersed into a 3.5 mg / mL suspension, and dopamine-modified PEEK was immersed in it. After standing at 4℃ for 12 h, it was dried under vacuum at 65℃ for 7 h to obtain the target material.

[0047] Example 7: This embodiment is based on the material of Embodiment 1 above, and grafts RGD peptides to improve cell compatibility. Because the existing heterojunction material has insufficient surface biocompatibility, the ability of bone cells to adhere and proliferate on the material surface is limited, which affects the bone repair efficiency.

[0048] Material composition The bioheterogeneous structure is BiVO4:CaTe=2:1, with 0.5wt% arginine-glycine-aspartic acid (RGD) peptide grafted onto the surface and loaded onto a PEEK matrix with a loading amount of 14wt%.

[0049] Preparation method Preparation of biological heterojunctions: BiVO4 / CaTe heterojunction powder was prepared according to the method in Example 4, dispersed in PBS buffer, and RGD peptide was added to a concentration of 0.5 wt%. The mixture was stirred at 37°C for 6 h, centrifuged to collect the powder, washed three times with PBS buffer, and vacuum dried at 60°C for 8 h to obtain RGD-grafted BiVO4 / CaTe heterojunctions.

[0050] The PEEK pretreatment and dopamine modification steps are the same as in Example 4.

[0051] Loading: The RGD-grafted BiVO4 / CaTe heterojunction was dispersed into a 3 mg / mL suspension, and dopamine-modified PEEK was immersed in it. After standing at 4℃ for 12 h, it was dried under vacuum at 65℃ for 8 h to obtain the target material.

[0052] To verify the effectiveness of the materials provided in the embodiments, the following experimental results are provided.

[0053] Experiment 1: Piezoelectric Performance Test Experimental materials The target materials of Examples 1-7 are: pure PEEK material, pure BiVO4 powder, dopamine-modified PEEK without heterojunction (control group 1), and unmodified BiVO4 / CaSe (2:1) loaded PEEK (control group 2, without annealing treatment).

[0054] Test methods piezoelectric constant (d 33 Testing: A piezoelectric constant tester, model ZJ-3A, was used to test the piezoelectric constant of each material at room temperature. 33 For the value test, 5 different sites were tested for each sample, and the average value was taken; the experiment was independently repeated 3 times, and the data were expressed as "mean ± standard deviation".

[0055] Piezoelectric current test: The material was cut into 10mm×10mm×2mm samples, gold electrodes were sputtered on the upper and lower surfaces, and connected to an electrochemical workstation (model: CHI660E). The peak value of the piezoelectric current generated by the material was tested under ultrasonic excitation at a frequency of 20kHz and a power of 0.2-1.5W / cm².

[0056] Statistical analysis: Independent samples t-tests were performed using SPSS 26.0 software, and p < 0.05 was considered statistically significant.

[0057] Specifically as follows: Sample piezoelectric constant d 33 (pC / N) Peak piezoelectric current (μA) at 0.5 W / cm² ultrasonic power Peak piezoelectric current (μA) at 1.0 W / cm² ultrasonic power Pure PEEK 0±0 0±0 0±0 pure bi v o4 powder 6.2±0.8 - (No substrate support, unable to stabilize test) - (No substrate support, unable to stabilize test) Control 1 0±0 0±0 0±0 Control 2 14.5±1.1 0.82±0.09 1.56±0.15 Example 1 (Wide range of materials, average) 12.3±1.8 0.65±0.08 1.38±0.16 Example 2 11.8±1.3 0.61±0.07 1.32±0.14 Example 3 18.6±1.7 1.05±0.10 2.12±0.21 Example 4 13.2±1.5 0.73±0.09 1.48±0.17 Example 5 (with HA) 17.9±1.6 1.01±0.11 2.05±0.19 Example 6 (annealed) 24.3±2.3 1.58±0.14 3.22±0.28 Example 7 (RGD grafting) 18.1±1.9 1.03±0.10 2.08±0.20 Results Analysis Pure PEEK and control group 1 showed no piezoelectric properties, proving that the piezoelectric effect originated from the biological heterostructure (p<0.001); the piezoelectric constant and piezoelectric current of Example 3 were significantly higher than those of control group 2 (p<0.05), verifying that the molar ratio was optimal; after annealing, the piezoelectric properties of Example 6 were greatly improved (p<0.01), and the optimization of crystal crystallinity was the reason for the improvement in piezoelectric properties; the piezoelectric properties of Examples 5 and 7 were not significantly different from those of Example 3 (p>0.05), proving that HA composite and RGD grafting did not impair the piezoelectric effect.

[0058] Experiment 2: Test of Acoustic Catalytic Antibacterial Performance Experimental materials The target materials in Examples 1-7, pure PEEK (control group 3), control group 2, and commercial antibiotic bone implant materials (control group 4, containing cefazolin).

[0059] Test methods Pathogen selection: Staphylococcus aureus (ATCC25923) and Escherichia coli (ATCC25922) are both common pathogens of bone implant infection.

[0060] Preparation of bacterial culture: The pathogenic bacteria were inoculated into LB medium and incubated at 37°C for 12 h, then diluted to a concentration of 1×10⁻⁶. 6 CFU / mL.

[0061] Antibacterial test: Each material sample (10mm×10mm×2mm) was placed in a 24-well plate, and 1mL of bacterial solution was added to each well. The samples were treated under the following conditions: no sonication, sonication (20kHz, 0.5W / cm², 30min), and sonication (20kHz, 1.0W / cm², 30min). After treatment, the bacterial solutions were serially diluted, spread on LB agar plates, and incubated at 37℃ for 18h. The number of colonies was counted, and the inhibition rate and sterilization rate were calculated.

[0062] Statistical analysis: One-way ANOVA was performed using SPSS 26.0 software. The LSD method was used for comparisons between groups, and p < 0.05 was considered statistically significant.

[0063] Antibacterial rate = (Number of colonies in control group - Number of colonies in experimental group) / Number of colonies in control group × 100% Sterilization rate = (Number of colonies in control group - Number of surviving colonies in experimental group) / Number of colonies in control group × 100% The details are shown in the table below: Sample Test condition S. aureus inhibition rate (%) S. aureus sterilization rate (%) E. coli inhibition rate (%) E. coli sterilization rate (%) Control 3 (Pure PEEK) No ultrasonic 0±1.2 0±0 0±1.0 0±0 Control 3 (Pure PEEK) Ultrasonic 0.5 W / cm², 30 min 2.3±0.8 0±0 1.8±0.7 0±0 Control 2 Ultrasonic 0.5 W / cm², 30 min 82.5±3.6 71.3±4.2 78.6±3.1 67.5±3.8 Control 4 (antibiotic) No ultrasonic 90.2±3.3 85.6±3.5 88.7±3.0 83.2±3.6 Example 3 Ultrasonic 0.5 W / cm², 30 min 95.8±2.7 89.7±3.1 93.6±2.9 87.3±3.4 Example 3 Ultrasonic 1.0 W / cm², 30 min 99.2±0.8 96.5±1.5 98.7±1.2 94.8±2.1 Example 5 (with HA) Ultrasonic 0.5 W / cm², 30 min 94.9±3.2 88.5±3.5 92.8±3.3 86.1±3.7 Example 6 (annealed) Ultrasonic 0.5 W / cm², 30 min 98.5±1.7 94.2±2.4 97.8±1.9 92.5±2.8 Example 7 (RGD grafting) Ultrasonic 0.5 W / cm², 30 min 95.3±2.9 89.1±3.3 93.1±3.0 86.7±3.5 Results Analysis Pure PEEK had no antibacterial effect (p>0.05), and ultrasound only slightly affected the colony count. The antibacterial effect of Example 3 was significantly better than that of Control Group 2 (p<0.05), approaching that of commercial antibiotic materials at low power (p>0.05), and the sterilization rate exceeded 94% at high power. After annealing, the antibacterial / sterilization rate of Example 6 at low power was significantly improved (p<0.01), proving that enhanced piezoelectric response at low power can directly improve the antibacterial effect. The antibacterial effects of Examples 5 and 7 were not significantly different from those of Example 3 (p>0.05), indicating that the introduction of HA and RGD did not affect the acoustic catalytic antibacterial performance.

[0064] Experiment 3: Load Stability Test Experimental materials Example 5 (with HA), Example 3 (without HA), and Control Group 2.

[0065] Test methods Simulated body fluid immersion: The samples were immersed in simulated body fluid (SBF, pH=7.4) and oscillated at 37℃ (100r / min) for 7d, 14d and 28d respectively; the experiment was independently repeated 3 times.

[0066] Load shedding rate test: After soaking, take out the sample, rinse the surface with deionized water, and vacuum dry to constant weight. Calculate the mass loss rate (shedding rate) = (mass before soaking - mass after soaking) / load before soaking × 100%.

[0067] Piezoelectric property retention rate test: The d of the sample after immersion was tested. 33 The retention rate was calculated as (value after immersion / value before immersion) × 100% based on the piezoelectric current at 0.5 W / cm² of ultrasound.

[0068] It should be noted that the HA surface is rich in hydroxyl groups, which can form hydrogen bonds with the amino groups on the PEEK surface modified by dopamine. At the same time, the calcium ions of HA can form coordinate bonds with the oxygen atoms on the surface of the BiVO4 / CaS heterojunction. This dual effect enhances the binding force between the heterojunction and the matrix, reducing detachment in the body fluid environment.

[0069] Test Results Sample Soaking time Load shedding rate (%) piezoelectric constant d 33 retention (%)]]> Piezoelectric current retention rate (%) Control 2 7d 8.6±1.3 85.3±2.1 83.5±2.3 Control 2 14d 15.8±2.1 72.6±2.5 70.8±2.6 Control 2 28d 27.3±2.8 58.4±4.5 56.2±4.8 Example 3 7d 6.2±1.1 89.7±2.9 88.2±3.1 Example 3 14d 11.5±1.7 78.5±3.4 76.9±3.7 Example 3 28d 20.7±2.3 65.8±4.2 64.3±4.5 Example 5 (with HA) 7d 4.8±0.9 96.8±2.1 95.7±2.5 Example 5 (with HA) 14d 8.3±1.5 91.5±2.7 90.3±3.0 Example 5 (with HA) 28d 14.6±2.0 85.2±3.3 83.6±3.6 Results Analysis The load shedding rate of Example 5 (including HA) was significantly lower than that of Example 3 and Control Group 2 (p<0.05), with a shedding rate of 14.6% at 28 days, a decrease of 46.5% compared to Control Group 2; the piezoelectric property retention rate was also significantly improved (p<0.05), with a d... 33 With a retention rate of 85.2%, combined with SEM characterization and binding mechanism analysis, it was confirmed that HA effectively improved the binding stability of the biological heterostructure and the PEEK matrix through the dual effects of hydrogen bonds and coordination bonds, thus solving the technical problem of load detachment in the body fluid environment.

[0070] Experiment 4: Test of bone repair performance Experimental materials Examples 3, 5, and 7: pure PEEK (control group 3), control group 2, and commercially available PEEK bone implant material (control group 5).

[0071] Test methods Cell culture: Rabbit bone marrow mesenchymal stem cells (BMSCs) were seeded in DMEM medium containing 10% fetal bovine serum and cultured at 37°C and 5% CO2.

[0072] Cell proliferation assay (CCK-8 assay): Place each material sample in a 96-well plate, seeding 1 × 10⁶ cells per well. 4 BMSCs were cultured for 1 day, 3 days, and 7 days respectively. 10 μL CCK-8 reagent was added to each well, and the cells were cultured for another 4 hours. The absorbance (OD value) was measured using a microplate reader (450 nm wavelength). The proliferation rate was calculated as (OD value of experimental group / OD value of control group) × 100%.

[0073] Alkaline phosphatase (ALP) activity assay: ALP activity was tested using an ALP activity assay kit (Nanjing Jiancheng) after 7 and 14 days of cell culture. The relative activity was calculated based on the activity of control group 3.

[0074] Hydrophilicity characterization: The water contact angle of each material surface was measured using a contact angle meter. Five sites were tested for each sample, and the average value was taken. The results showed that the contact angle of Example 7 (RGD grafting) was 42.3±2.5°, which was significantly lower than that of Example 3 (65.7±3.1°) (p<0.01), confirming that RGD grafting improved the hydrophilicity of the material and provided favorable conditions for cell adhesion.

[0075] Statistical analysis: ANOVA analysis was performed using SPSS 26.0 software, and p < 0.05 was considered statistically significant.

[0076] Test Results Sample Culture time Cell proliferation rate (%) ALP relative activity (%) Control 3 (Pure PEEK) 1d 100.0±3.2 - (1d no ALP detected) Control 3 (Pure PEEK) 3d 128.5±5.3 - (3d no ALP detected) Control 3 (Pure PEEK) 7d 186.3±6.7 100.0±5.8 Control 3 (Pure PEEK) 14d 253.7±7.2 132.5±6.4 Control 2 1d 112.6±4.8 - Control 2 3d 145.8±5.6 - Control 2 7d 218.7±6.3 128.3±6.1 Control 2 14d 296.5±7.5 165.8±6.8 Control 5 (commercial) 1d 115.3±4.9 - Control 5 (commercial) 3d 150.2±5.8 - Control 5 (commercial) 7d 225.6±6.5 135.7±6.3 Control 5 (commercial) 14d 308.4±7.8 172.4±7.1 Example 3 1d 120.5±5.1 - Example 3 3d 158.7±6.0 - Example 3 7d 236.8±7.1 142.6±6.5 Example 3 14d 325.7±8.0 186.3±7.3 Example 5 (with HA) 1d 132.8±5.5 - Example 5 (with HA) 3d 175.6±6.4 - Example 5 (with HA) 7d 268.5±7.5 178.4±7.0 Example 5 (with HA) 14d 372.4±8.3 235.6±7.8 Example 7 (RGD grafting) 1d 145.3±5.8 - Example 7 (RGD grafting) 3d 192.7±6.7 - Example 7 (RGD grafting) 7d 289.6±7.9 195.8±7.5 Example 7 (RGD grafting) 14d 405.2±8.6 268.3±8.2 Results Analysis Example 3 showed better bone repair performance than controls 2 and 5 (p<0.05), demonstrating that the BiVO4 / CaX heterostructure itself has a bone-promoting effect; Example 5 (containing HA) showed significantly increased cell proliferation rate and ALP activity (p<0.05), because HA is a natural bone tissue component and can synergistically promote bone differentiation with calcium ions released by CaS; Example 7 (RGD grafting) showed the best effect (p<0.01), and combined with the contact angle characterization results, it was confirmed that the RGD peptide effectively improved cell compatibility by improving hydrophilicity and cell-specific binding, thus solving the technical problem of insufficient bone cell adhesion and proliferation.

[0077] Experiment 5: Solving the problem of multidrug-resistant bacterial infections Technical issues Existing antibiotic bone implant materials are ineffective against multidrug-resistant bacteria (such as methicillin-resistant Staphylococcus aureus, MRSA), while the material in this application can avoid bacterial resistance through a piezoelectric catalytic mechanism, providing a solution for multidrug-resistant bacterial infections.

[0078] Experimental materials Examples 3 and 6, control group 4 (commercial antibiotic material), pure PEEK (control group 3).

[0079] Test methods Methicillin-resistant Staphylococcus aureus (MRSA, ATCC43300) was selected, and bacterial suspension (1×10⁻⁶) was prepared according to the method in Experiment 2. 6 The antibacterial effect was tested under ultrasound conditions (20 kHz, 0.5 W / cm², 30 min), with a control group without ultrasound included. Details are as follows: Sample Test condition MRSA inhibition rate (%) MRSA sterilization rate (%) Control 3 (Pure PEEK) Ultrasonic 0.5 W / cm², 30 min 3.2±0.6 0 Control 4 (antibiotic) No ultrasonic 28.5±2.3 15.6±1.8 Control 4 (antibiotic) Ultrasonic 0.5 W / cm², 30 min 32.7±2.5 18.9±2.0 Example 3 Ultrasonic 0.5 W / cm², 30 min 94.2±1.5 87.6±1.9 Example 6 (annealed) Ultrasonic 0.5 W / cm², 30 min 97.8±0.9 93.5±1.3 Results Analysis Commercial antibiotic materials showed an inhibition rate of only 32.7% and a sterilization rate of less than 20% against MRSA, while Examples 3 and 6 showed inhibition rates of over 94% and sterilization rates of over 87% against MRSA, demonstrating that the materials in this application can effectively solve the technical problem of multidrug-resistant bacterial infections.

[0080] The above experiments demonstrate that this material overcomes the limitation of PEEK bone implant materials relying on near-infrared photocatalysis in existing technologies. It loads a bio-heterogeneous junction formed by BiVO4 and chalcogenides onto PEEK, achieving a synergistic effect of acoustic catalytic antibacterial and bone repair promotion. Furthermore, its piezoelectric properties can be controlled by ultrasonic power to meet clinical needs.

[0081] To address the unresolved technical problems of poor load stability, insufficient low-power piezoelectric response, limited cell compatibility, and difficulty in dealing with multidrug-resistant bacterial infections, we introduced improvement methods such as HA composite, annealing treatment, and RGD grafting. The effectiveness of each improvement scheme was verified through experiments.

[0082] The piezoelectric effect is a force-electric conversion characteristic. Although it and the photoelectric characteristics of existing technologies are both energy conversion characteristics of semiconductor materials, there are fundamental differences in the triggering method and the mechanism of action. Furthermore, this application has achieved unique effects such as low-power triggering, high stability, and resistance to drug-resistant bacteria.

[0083] This invention is not limited to the optional embodiments described above, and anyone can derive other various forms of products based on the inspiration of this invention. The specific embodiments described above should not be construed as limiting the scope of protection of this invention; the scope of protection of this invention should be determined by the claims, and the specification can be used to interpret the claims.

Claims

1. A PEEK bone implant material with piezoelectric catalytic bioheterostructure, characterized in that: The invention comprises a PEEK bone implant loaded with a bioheterogeneous material, the bioheterogeneous material being composed of BiVO4 and chalcogenides in a molar ratio ranging from 1 to 3.

2. The PEEK bone implant material of piezoelectric catalytic bioheterostructure according to claim 1, characterized in that: The bio-heterojunction material is composed of BiVO4 and chalcogenides in a molar ratio of 2:

1.

3. The PEEK bone implant material of piezoelectric catalytic bioheterostructure according to claim 1, characterized in that: The chalcogenides include one of calcium sulfide, calcium selenide, and calcium telluride.

4. A preparation method, characterized in that: The PEEK bone implant material used to prepare the piezoelectric catalytic bioheterostructure of any one of claims 1-3 is as follows: First, a bio-heterogeneous material is prepared by adding chalcogenide calcium compounds to a BiVO4 mixed solution containing ethylene glycol to form a reaction solution. Then, a liquid system containing the bio-heterogeneous material is formed by hydrothermal method or in-situ composite method. After washing the liquid system alternately with anhydrous ethanol and deionized water and drying, BiVO4 / CaX bio-heterogeneous material is obtained. The obtained BiVO4 / CaX bio-heterogeneous material is loaded onto PEEK material to form a bone implant material.

5. The preparation method according to claim 4, characterized in that: The BiVO4 mixed solution is prepared by dissolving anhydrous bismuth nitrate and ammonium vanadate in a mixed solution of ethylene glycol and deionized water through ultrasonic treatment.

6. The preparation method according to claim 4, characterized in that: In the preparation of bone implant materials, PEEK material is first cleaned with acetone, ethanol and deionized water, and then subjected to ultrasonic treatment with sulfuric acid for 5-10 minutes to obtain sulfonated PEEK material. Prepare a 10 mmol / L Tris solution, adjust the pH of the Tris solution to 8.5 with dilute hydrochloric acid, and then add 2 mg / mL of dopamine hydrochloride to the Tris solution to obtain a dopamine solution. Sulfonated PEEK material was reacted with dopamine solution for 24 hours and then dried to obtain dopamine-modified PEEK material. The obtained BiVO4 / CaX bioheterostructure was fully contacted with dopamine-modified PEEK material at 4℃ for 12 hours to obtain bone implant material.

7. The preparation method according to claim 4, characterized in that: When forming a liquid system containing biological heterostructures using hydrothermal or in-situ composite methods, the heating temperature is 160℃ and the holding time is at least 6 hours.