A biological heterojunction material with both antibacterial and bone nerve repair properties, and its preparation method and application

Abstract

The invention discloses a preparation method of a biological heterojunction material with both antibacterial and bone nerve repair properties, comprising the following steps: S1, dissolving bismuth nitrate pentahydrate and potassium chloride in water respectively, adding KCl solution to Bi(NO)3·5H2O solution to obtain BiOCl powder; S2, dissolving pyrrole monomer and ferric chloride hexahydrate in water respectively, adding FeCl3·6H2O solution to Py solution to obtain PPy; S3, adding BiOCl powder to water and stirring, adding FeCl3·6H2O, and adding Py monomer during stirring to obtain BiOCl@PPy heterojunction; S4, adding concentrated sulfuric acid to a polyetheretherketone substrate to obtain S-PEEK, adding the S-PEEK substrate to a polydopamine solution to obtain PS-PEEK, and dripping the BiOCl@PPy heterojunction solution onto the surface of the PS-PEEK to obtain BiOCl@PPy@PS-PEEK. By combining bismuth oxychloride with polypyrrole, the recombination rate of electron-hole pairs in bismuth oxychloride is effectively delayed, the yield of ROS is increased, and the antibacterial efficiency of the material is enhanced. By compounding with polyetheretherketone, it has both long-lasting antibacterial ability and a nerve repair-promoting effect, achieving efficient repair of bone defects infected by drug-resistant bacteria and reconstruction of nerve function.

Description

Technical Field

[0001] The present invention relates to the technical field of biomaterials, in particular to prosthetic materials, specifically to a biological heterojunction material with both antibacterial and bone-nerve repair properties, and a preparation method and application thereof. Background Art

[0002] Bacterial infection after bone and joint surgery is an extremely devastating and difficult-to-treat complication in orthopedic clinics. Currently, the commonly used treatments in clinical practice are surgery or debridement, but long-term use can lead to antibiotic resistance, hinder tissue healing, and increase the risk of local or systemic adverse reactions, placing a huge burden on patients. In addition, some patients with neuropathy are more likely to suffer from bone tissue-related diseases, such as bone tissue infection, fractures, and joint dislocations. The interaction between nervous tissue and bone tissue is intricate, indicating that neurogenic regulation is crucial in bone metabolism and repair.

[0003] Therefore, it is of great significance to design a material that does not rely on antibiotics to achieve antibacterial effect and has bone and nerve repair effects. Summary of the Invention

[0004] The present invention overcomes the deficiencies of the prior art and provides a biological heterojunction material having both antibacterial and bone nerve repair properties, as well as a preparation method and application thereof.

[0005] To achieve the above-mentioned object, the technical solution adopted by the present invention is: a method for preparing a biological heterojunction material with both antibacterial and bone nerve repair properties, comprising the following steps:

[0006] S1. Dissolving bismuth nitrate pentahydrate and potassium chloride in water at certain concentrations to obtain a Bi(NO)3·5H2O solution and a KCl solution, respectively. Adding the KCl solution dropwise to the Bi(NO)3·5H2O solution, stirring magnetically and then performing a hydrothermal reaction to obtain BiOCl powder.

[0007] S2. Pyrrole monomer is added dropwise to water at a certain concentration and stirred to dissolve. Ferric chloride hexahydrate is added to water at a certain concentration and ultrasonically dissolved. Then, FeCl3·6H2O solution is slowly added dropwise to the Py solution and magnetically stirred. After the reaction is completed, the mixture is washed alternately with anhydrous ethanol and water for 3-5 times and dried in a freeze dryer to obtain PPy.

[0008] S3, BiOCl powder was added to water at a certain concentration, magnetically stirred once, and then FeCl3·6H2O was added and magnetically stirred twice. During the stirring process, Py monomer was added and magnetically stirred three times at room temperature. The resulting suspension was magnetically separated, repeatedly washed with water, and freeze-dried to obtain a BiOCl@PPy heterojunction;

[0009] S4. Add the polyetheretherketone substrate to concentrated sulfuric acid and sonicate for 5 to 10 minutes. Then add it to acetone-water and repeatedly wash and dry it to obtain S-PEEK with a porous surface structure. Add the sulfonated PEEK to the polydopamine solution, stir and dry it to obtain PS-PEEK. Then, add the BiOCl@PPy heterojunction solution dropwise to the PS-PEEK surface multiple times and dry it to obtain BiOCl@PPy@PS-PEEK.

[0010] In a preferred embodiment of the present invention, in step S1, the added concentration of bismuth nitrate pentahydrate is 0.04-0.08 mol / L; the added concentration of potassium chloride is 0.08-0.12 mol / L; the magnetic stirring time is 1-2 hours; the temperature of the hydrothermal reaction is: 150-170°C, and the time is 4-6 hours.

[0011] In a preferred embodiment of the present invention, in step S2, the concentration of the pyrrole monomer added is 0.6-0.8 mol / L; the concentration of the ferric chloride hexahydrate added is 0.25-0.4 mol / L.

[0012] In a preferred embodiment of the present invention, in step S2, the stirring and dissolving time is 20 to 60 minutes; the ultrasonic dissolving time is 20 to 60 minutes; the reaction time is 10 to 13 hours; and the drying temperature is -30 to -50°C and the drying time is 20 to 24 hours.

[0013] In a preferred embodiment of the present invention, in step S3, the added concentration of the BiOCl powder is 0.01-0.02 mol / L; and the mass ratio of the BiOCl powder, the Py monomer, and the FeCl3·6H2O is 1:1-1.15:0.65-0.88.

[0014] In a preferred embodiment of the present invention, in the step S3, the time of the first magnetic stirring is 20 to 50 minutes; the time of the second magnetic stirring is 20 to 50 minutes; the time of the third magnetic stirring is 20 to 24 hours; the temperature of the freeze-drying is -30 to -50°C, and the time is 20 to 24 hours.

[0015] In a preferred embodiment of the present invention, in step S4, the concentration of the BiOCl@PPy heterojunction solution is 180-210 μg / mL.

[0016] In a preferred embodiment of the present invention, in step S4, the number of washings is 2-4 times; the concentration of the polydopamine solution is 1-3 mg / mL; the stirring time is 20-24 hours; and the number of dropwise additions is 4-7 times.

[0017] The present invention provides a biological heterojunction material with both antibacterial and bone nerve repair properties, which is prepared by any one of the aforementioned preparation methods.

[0018] The present invention provides an application of the aforementioned biological heterojunction material in a hard tissue repair implant.

[0019] The present invention solves the defects existing in the background technology and has the following beneficial effects:

[0020] (1) The present invention provides a bioheterojunction material with both antibacterial and bone nerve repair properties, as well as a preparation method and application thereof. By combining lamellar bismuth oxychloride with excellent piezoelectric properties and unique energy band structure with polypyrrole with good conductivity and biocompatibility to form a heterojunction structure, the recombination rate of electron-hole pairs in bismuth oxychloride is effectively delayed, thereby increasing the yield of ROS and enhancing the antibacterial efficiency of the material. In addition, by compounding the bismuth oxychloride-polypyrrole bioheterojunction with polyetheretherketone, while maintaining excellent mechanical properties, it also has long-lasting antibacterial ability and the effect of promoting nerve repair, thereby achieving efficient repair of bone defects infected by drug-resistant bacteria and reconstruction of nerve function.

[0021] (2) In the present invention, polypyrrole formed by polymerization of pyrrole monomers has good conductivity and can not only transmit electrical signals to promote cell metabolism and proliferation, but also ensure the safety and effectiveness of the composite material in the body due to its excellent biocompatibility. Thus, through the charge transfer mechanism, the electron separation on the surface of bismuth oxychloride is further promoted, and the generation of ROS is synergistically enhanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments described in the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive efforts.

[0023] Figure 1 is a SEM morphology image of the material prepared in Example 1 of the present invention, wherein A is BiOCl, B is PPy, and C is a SEM morphology image of a BiOCl@PPy heterojunction;

[0024] Figure 2 1 is a graph of the sonodynamic performance of the material prepared in Example 1 of the present invention, wherein A is a fluorescence signal detected by a fluorescence spectrophotometer at an appropriate wavelength when SOSG is excited, reflecting the generation of singlet oxygen, and B is a fluorescence signal detected by a fluorescence spectrophotometer at an appropriate wavelength when TA is excited, reflecting the generation of hydroxyl radicals;

[0025] Figure 3 : This is an antibacterial effect diagram of the material prepared in Example 1 of the present invention, wherein A is an antibacterial effect diagram of methicillin-resistant Staphylococcus aureus, and B is an antibacterial effect diagram of drug-resistant Escherichia coli;

[0026] Figure 4 This is a diagram showing cell activity after co-culturing the material prepared in Example 1 of the present invention with PC12 cells;

[0027] Figure 5 Graphs showing the expression of nerve-related proteins in the material prepared in Example 1 of the present invention, wherein A shows the expression of Schwann cell repair and axon formation under ultrasound, and B shows the expression of NGF-related mRNA;

[0028] The correspondence between symbols and materials in the figure is as follows: Control represents the blank group; BPP represents BiOCl@PPy heterojunction; US(+) represents 1.0 W / cm 2 , 5min ultrasonic treatment; US(-) means no ultrasonic treatment; MRSA means methicillin-resistant Staphylococcus aureus; MDRE means drug-resistant Escherichia coli; S-PEEK means sulfonated PEEK, and the obtained PEEK surface has a porous structure; PS-PEEK means polydopamine is loaded on the surface of PEEK with a porous structure; the materials in the figures are all coated on PS-PEEK, which is omitted in the legend. PS-PEEK is represented by Control, BiOCl, PPy and BPP. DETAILED DESCRIPTION

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0030] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0031] Application Overview:

[0032] In recent years, reactive oxygen species (ROS) therapy has shown great potential due to its ability to rapidly destroy bacterial structures. This therapy relies on the highly reactive ROS to oxidize the lipids, nucleic acids, and proteins of pathogens, effectively disrupting the integrity of bacterial membranes and achieving rapid sterilization. Bismuth oxychloride (BiOCl), a two-dimensional sheet material with excellent piezoelectric properties and a unique band structure, can efficiently catalyze oxygen to produce reactive oxygen species in response to external stimuli, making it an ideal candidate for ROS therapy.

[0033] In-depth research revealed that the narrow band gap of bismuth oxychloride, as a single semiconductor material, accelerates the recombination process of electrons and holes, greatly limiting the production of ROS and resulting in reduced antibacterial efficiency. This discovery reveals the key technical bottleneck facing bismuth oxychloride in practical applications.

[0034] Therefore, in order to solve this problem, the applicant modified bismuth oxychloride to inhibit its rapid electron-hole recombination, thereby increasing the yield of ROS and enhancing the antibacterial effect.

[0035] In view of the above findings, the concept of the present invention is to propose a biological heterojunction material with both antibacterial and bone nerve repair properties, as well as its preparation method and application. By selecting bismuth oxychloride and polypyrrole to construct a heterojunction as the implant surface coating, the nerve-bone interaction is regulated and sterilization is induced, thereby promoting the transformation of bone defects infected by drug-resistant strains into a bone tissue repair environment around the implant.

[0036] It should be noted that the raw materials, equipment, reagents, etc. used in the present invention can be purchased from the market or obtained through existing preparation methods.

[0037] A method for preparing a biological heterojunction material having both antibacterial and bone nerve repair properties comprises the following steps:

[0038] S1. Dissolving bismuth nitrate pentahydrate and potassium chloride in water at certain concentrations to obtain a Bi(NO)3·5H2O solution and a KCl solution, respectively. Adding the KCl solution dropwise to the Bi(NO)3·5H2O solution, stirring magnetically and then performing a hydrothermal reaction to obtain BiOCl powder.

[0039] S2. Pyrrole monomer is added dropwise to water at a certain concentration and stirred to dissolve. Ferric chloride hexahydrate is added to water at a certain concentration and ultrasonically dissolved. Then, FeCl3·6H2O solution is slowly added dropwise to the Py solution and magnetically stirred. After the reaction is completed, the mixture is washed alternately with anhydrous ethanol and water for 3-5 times and dried in a freeze dryer to obtain PPy.

[0040] S3, BiOCl powder was added to water at a certain concentration, magnetically stirred once, and then FeCl3·6H2O was added and magnetically stirred twice. During the stirring process, Py monomer was added and magnetically stirred three times at room temperature. The resulting suspension was magnetically separated, repeatedly washed with water, and freeze-dried to obtain a BiOCl@PPy heterojunction;

[0041] S4. Add the polyetheretherketone substrate to concentrated sulfuric acid and sonicate for 5 to 10 minutes. Then add it to acetone-water and repeatedly wash and dry it to obtain S-PEEK with a porous surface structure. Add the sulfonated PEEK to the polydopamine solution, stir and dry it to obtain PS-PEEK. Then, add the BiOCl@PPy heterojunction solution dropwise to the PS-PEEK surface multiple times and dry it to obtain BiOCl@PPy@PS-PEEK.

[0042] In some specific embodiments, in step S1, the added concentration of bismuth nitrate pentahydrate is 0.04-0.08 mol / L; the added concentration of potassium chloride is 0.08-0.12 mol / L; the magnetic stirring time is 1-2 h; the hydrothermal reaction temperature is 150-170° C., and the time is 4-6 h.

[0043] In some specific embodiments, in step S2, the concentration of pyrrole monomer added is 0.6-0.8 mol / L; the concentration of ferric chloride hexahydrate added is 0.25-0.4 mol / L.

[0044] In some specific embodiments, in step S2, the stirring and dissolving time is 20 to 60 minutes; the ultrasonic dissolving time is 20 to 60 minutes; the reaction time is 10 to 13 hours; and the drying temperature is -30 to -50°C, and the drying time is 20 to 24 hours.

[0045] In some specific embodiments, in step S3, the added concentration of BiOCl powder is 0.01-0.02 mol / L; the mass ratio of BiOCl powder, Py monomer and FeCl3·6H2O is 1:1-1.15:0.65-0.88.

[0046] In some specific embodiments, in step S3, the time of the first magnetic stirring is 20 to 50 minutes; the time of the second magnetic stirring is 20 to 50 minutes; the time of the third magnetic stirring is 20 to 24 hours; the temperature of freeze-drying is -30 to -50°C, and the time is 20 to 24 hours.

[0047] In some specific embodiments, in step S4, the concentration of the BiOCl@PPy heterojunction solution is 180-210 μg / mL.

[0048] In some specific embodiments, in step S4, the number of washings is 2-4 times; the concentration of the polydopamine solution is 1-3 mg / mL; the stirring time is 20-24 h; and the number of dropwise additions is 4-7 times.

[0049] The present invention provides a biological heterojunction material with both antibacterial and bone nerve repair properties, which is prepared by any of the above-mentioned preparation methods.

[0050] The present invention provides an application of the aforementioned biological heterojunction material in a hard tissue repair implant.

[0051] Example 1

[0052] A method for preparing a biological heterojunction material having both antibacterial and bone nerve repair properties comprises the following steps:

[0053] S1. Dissolve 0.97 g of bismuth nitrate pentahydrate (Bi(NO)3·5H2O) in 40 mL of water and 0.15 g of potassium chloride (KCl) in 20 mL of water. Add the KCl solution dropwise to the Bi(NO)3·5H2O solution, stir magnetically for 1 h, and then perform a hydrothermal reaction at 160°C for 5 h to obtain BiOCl powder.

[0054] S2. Drop 5 mL of pyrrole (Py) monomer into 100 mL of water and stir to dissolve for 30 min. Add 8.6 g of ferric chloride hexahydrate (FeCl3·6H2O) into 100 mL of water and dissolve under ultrasonication for 30 min. Slowly add the FeCl3·6H2O solution dropwise to the Py solution and react for 12 h under magnetic stirring. After the reaction, wash with anhydrous ethanol and water alternately for 3 times and dry in a freeze dryer at -30°C for 24 h to obtain PPy.

[0055] S3. Add 362 mg of BiOCl powder to 100 mL of water and stir magnetically for 30 min. Then add 280 mg of FeCl3·6H2O and continue stirring magnetically for 30 min. During the stirring process, add 400 μL of Py monomer and stir magnetically at room temperature for 24 h. The resulting suspension is magnetically separated, washed repeatedly with water, and dried at -30°C for 24 h to obtain a BiOCl@PPy heterojunction.

[0056] S4. The polyetheretherketone substrate was added to concentrated sulfuric acid and ultrasonicated for 5 minutes. The substrate was then added to acetone-water-acetone-water for cleaning and drying to obtain S-PEEK with a porous surface structure. The sulfonated PEEK was added to a 2 mg / mL polydopamine solution, stirred for 24 hours, and dried to obtain PS-PEEK. A 200 μg / mL BiOCl@PPy heterojunction solution was then added dropwise to the PS-PEEK surface 5 times, 20 μL at a time, and dried to obtain BiOCl@PPy@PS-PEEK.

[0057] In order to verify the successful acquisition of BiOCl, PPy and BiOCl@PPy heterojunctions in Example 1, Figure 1 A shows the BiOCl of Example 1, B shows the PPy of Example 1, and C shows the SEM morphology of the BiOCl@PPy heterojunction of Example 1.

[0058] Reactive oxygen release experiment:

[0059] Experiment 1: The sulfonated polyetheretherketone bone repair material (Control), bismuth oxychloride-coated polyetheretherketone bone repair material (BiOCl@PS-PEEK), polypyrrole-coated polyetheretherketone bone repair material (PPy@PS-PEEK), and bismuth oxychloride-polypyrrole bioheterojunction-coated polyetheretherketone bone repair material (BiOCl@PPy@PS-PEEK) prepared in Example 1 were placed in a 48-well plate, and water was used as a dispersant. 1 μL of singlet oxygen green fluorescent probe was added thereto, and the mixture was gently ultrasonically mixed. The mixture was ultrasonically treated (1.0 W / cm 2 8min), the mixed solution was centrifuged, 100 μL was added to 3 mL of water, and the fluorescence intensity was measured using a fluorescence spectrophotometer. The test results are shown in Figure 2 A.

[0060] Experiment 2: Replace 1 μL of singlet oxygen green fluorescent probe with 100 μL of terephthalic acid and repeat the operation of Experiment 1. The test results are shown in Figure 2 B.

[0061] Experimental results: From Figure 2 It can be seen that compared with PS-PEEK, BiOCl@PS-PEEK or PPy@PS-PEEK, BiOCl@PPy@PS-PEEK is more conducive to the production of reactive oxygen species under ultrasonic excitation conditions, thereby achieving better antibacterial effect.

[0062] Antibacterial experiment:

[0063] Experiment 1: Gram-positive methicillin-resistant Staphylococcus aureus was used for antibacterial experiments. The bacteria were cultured in LB medium at 37°C in a constant temperature shaker for 12 hours. The bacteria were diluted in a 48-well plate until the concentration reached 10 4 colony forming unit (CFU) mL -1 Bacteria were co-cultured with PS-PEEK, BiOCl@PS-PEEK, PPy@PS-PEEK, and BiOCl@PPy@PS-PEEK. The sample amount was 200 μg in the bacterial suspension. The bacterial suspension samples of the +US group were ultrasonically treated at an intensity of 1.0 W / cm 2 The treated samples were then co-cultured with bacteria for 8 minutes. 100 μL of the treated bacterial suspension was added to LB agar medium and spread on the plate using a spreader. The plate was incubated at 37°C for 24 hours to observe the growth of the colonies. The test results are shown in the table. Figure 3 A.

[0064] Experiment 2: Replace methicillin-resistant Staphylococcus aureus with drug-resistant Escherichia coli and repeat the above experimental operation to obtain the antibacterial effect of each material on drug-resistant Escherichia coli. The test results are shown in Figure 3 B.

[0065] Experimental results: From Figure 3 It can be seen that BiOCl@PPy@PS-PEEK has a significant antibacterial effect under ultrasound, while BiOCl@PS-PEEK and PPy@PS-PEEK have limited inhibitory effects on bacterial growth. At the same time, PS-PEEK has no antibacterial effect. Therefore, BiOCl@PPy@PS-PEEK has a good antibacterial effect under ultrasonic excitation conditions.

[0066] Biosafety (cytotoxicity) evaluation experiment:

[0067] PC12 / Schwann cells were cultured in DMEM containing 10% fetal bovine serum. After the cells adhered to the wall and grew, fresh culture medium was replaced. When the cell fusion rate reached 80%, the cells were cultured at 10 4 The cells were seeded at a density of 100 μg / well on a 24-well plate and cultured for 24 hours. The cells were then seeded into a 24-well plate containing the PS-PEEK, BiOCl@PS-PEEK, PPy@PS-PEEK, and BiOCl@PPy@PS-PEEK materials prepared in Example 1. Three parallel groups were set up in each group and cultured again for 24 hours. The biocompatibility of the materials was then tested using a CCK-8 kit, and the absorbance of each group was measured at a wavelength of 450 nm using an enzyme reader. The absorbance represents cell activity, and the test results are shown in Table 1. Figure 4 .

[0068] Experimental results: From Figure 4 It can be seen that the cell activity of BiOCl@PPy@PS-PEEK is not much different from that of the other groups, which proves its excellent biocompatibility.

[0069] Neural-related protein expression experiment:

[0070] First, the rat neural gene sequence was searched in GenBank, and the relevant primers were designed and synthesized, with GAPDH as the internal reference. Then, total RNA was extracted from the cell sample. This process includes cell lysis, genomic DNA removal, RNA adsorption, impurity removal, and RNA elution to obtain high-purity RNA. Next, the residual genomic DNA was removed and a reverse transcription reaction was performed. Subsequently, a real-time fluorescence PCR reaction was performed. Finally, the experimental results were processed using the relative quantification method, and the test results are shown in Figure 2. Figure 5 A and Figure 5 B.

[0071] Experimental results: From Figure 5 It can be seen that BiOCl@PPy@PS-PEEK has better expression of nerve-related proteins than other groups, proving its good ability to promote the expression of nerve-related proteins.

[0072] In summary, the present invention combines lamellar bismuth oxychloride with excellent piezoelectric properties and a unique energy band structure with polypyrrole with good conductivity and biocompatibility to form a heterojunction structure, which effectively delays the recombination rate of electron-hole pairs in bismuth oxychloride, thereby increasing the yield of ROS and enhancing the antibacterial efficiency of the material. In addition, by compounding the bismuth oxychloride-polypyrrole bioheterojunction with polyetheretherketone, while maintaining excellent mechanical properties, it also has long-lasting antibacterial ability and the effect of promoting nerve repair, thereby achieving efficient repair of bone defects infected by drug-resistant bacteria and reconstruction of nerve function.

[0073] By utilizing the polypyrrole formed after polymerization of pyrrole monomers, it has good conductivity and can not only transmit electrical signals to promote cell metabolism and proliferation, but its excellent biocompatibility also ensures the safety and effectiveness of the composite material in the body. It further promotes the electron separation on the surface of bismuth oxychloride through the charge transfer mechanism, and synergistically enhances the generation of ROS.

[0074] In order to further make the purpose and effect of the present invention simple and easy to understand, the present invention is further described in conjunction with examples and comparative examples.

[0075] Example 2

[0076] This embodiment is substantially the same as embodiment 1, except that in step S3, the amount of FeCl3·6H2O used is 241 mg, that is, the mass ratio of BiOCl powder, Py monomer, and FeCl3·6H2O is 1:1.07:0.67.

[0077] Example 3

[0078] This embodiment is substantially the same as embodiment 1, except that in step S3, the amount of FeCl3·6H2O used is 313 mg, that is, the mass ratio of BiOCl powder, Py monomer, and FeCl3·6H2O is 1:1.07:0.87.

[0079] Example 4

[0080] This embodiment is substantially the same as embodiment 1, except that in step S4, the concentration of the BiOCl@PPy heterojunction solution is 185 μg / mL.

[0081] Example 5

[0082] This embodiment is substantially the same as embodiment 1, except that in step S4, the concentration of the BiOCl@PPy heterojunction solution is 206 μg / mL.

[0083] Comparative Example 1

[0084] This comparative example is basically the same as Example 1, except that in step S3, the amount of FeCl3·6H2O used is 222 mg, that is, the mass ratio of BiOCl powder, Py monomer and FeCl3·6H2O is 1:1.07:0.61.

[0085] Comparative Example 2

[0086] This comparative example is basically the same as Example 1, except that in step S3, the amount of FeCl3·6H2O used is 324 mg, that is, the mass ratio of BiOCl powder, Py monomer and FeCl3·6H2O is 1:1.07:0.90.

[0087] Comparative Example 3

[0088] This comparative example is substantially the same as Example 1, except that in step S4, the concentration of the BiOCl@PPy heterojunction solution is 174 μg / mL.

[0089] Comparative Example 4

[0090] This comparative example is substantially the same as Example 1, except that in step S4, the concentration of the BiOCl@PPy heterojunction solution is 221 μg / mL.

[0091] The BiOCl@PPy@PS-PEEK obtained in Examples 2-5 and Comparative Examples 1-4 were tested using the same active oxygen release experiment (Experiment 1) and antibacterial experiment (Experiments 1 and 2) as the BiOCl@PPy@PS-PEEK obtained in Example 1. The performance test results are shown in Table 1.

[0092] Table 1:

[0093]

[0094]

[0095] As shown in Table 1, in order to illustrate the rationality of the formula between BiOCl powder, Py monomer and FeCl3·6H2O in the above scheme, by comparing Example 1 with Example 2 and Example 3, it can be seen that the experiment verified that precise control of the FeCl3·6H2O content can effectively increase the yield of ROS and ensure that the biological heterojunction material has good antibacterial efficiency and effect.

[0096] Specifically, the electrons in the conduction band of BiOCl jump to the LUMO orbit of PPy under ultrasonic or mechanical stimulation, while the holes in the valence band of BiOCl are retained. The type II band structure formed at the heterojunction interface can significantly prolong the lifetime of electron-hole pairs and promote the continuous generation of ROS. 3+ As an oxidant, the doping state of PPy chains is formed during the polymerization of pyrrole monomers, ensuring that PPy has high conductivity. Then, the appropriate amount of FeCl3·6H2O can make Fe 3+ The concentration can fully oxidize the pyrrole monomer to form a continuous, conjugated PPy network, while not excessively occupying the active sites on the BiOCl surface, thereby maintaining the smooth interface charge transfer channel of the heterojunction.

[0097] And by comparing Example 1 with Comparative Example 1 and Comparative Example 2, it can be seen that the dosage is too low to cause Fe 3+ Insufficient concentration leads to incomplete oxidation of pyrrole monomers, shortened PPy chain length and incomplete conjugated structure, which weakens its ability to act as an electron acceptor. As a result, the electrons in the BiOCl conduction band cannot be effectively transferred to PPy, resulting in accelerated electron-hole recombination rate, decreased ROS production, and significantly reduced antibacterial efficiency. 3+ Fe(OH)3 colloidal precipitation forms on the BiOCl surface, covering the active sites of BiOCl, hindering the photo / piezoelectric excitation process, and causing over-doping of PPy, destroying the continuity of its conjugated π electron system, forming conductive "islands", and hindering the overall charge migration, thereby resulting in a simultaneous decrease in ROS yield and antibacterial effect.

[0098] By comparing Example 1 with Example 4 and Example 5, it can be seen that after the BiOCl@PPy heterojunction solution with an appropriate concentration is dropped onto the PS-PEEK surface, the polydopamine coating on the PS-PEEK surface is rich in phenolic hydroxyl and amino functional groups, which form a stable interface with the BiOCl@PPy heterojunction through hydrogen bonding and π-π stacking. - It forms an electrostatic interaction with the amino group of dopamine, while the conjugated π electron system of PPy produces π-π conjugation with the benzene ring of dopamine, ensuring that the heterojunction is evenly distributed and firmly attached, thereby ensuring the ROS generation efficiency and antibacterial effect. By comparing Example 1 with Comparative Examples 3 and 4, it can be seen that low-concentration solutions are difficult to form continuous coverage on the PS-PEEK surface, resulting in sparse distribution of heterojunctions, insufficient exposure of active sites, and discontinuous interfacial charge transfer paths between BiOCl and PPy, further weakening the ROS yield. High-concentration solutions easily form multilayer stacking on the PS-PEEK surface, resulting in an extension of the charge transfer path of the BiOCl@PPy heterojunction and masking the active sites of BiOCl and PPy, hindering ROS generation and electrical signal transmission, thereby reducing antibacterial efficiency and effect.

[0099] The above description is based on the ideal embodiment of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the embodiments should be considered as illustrative and non-restrictive in all respects. The scope of the present invention is defined by the appended claims, not the foregoing description, and it is intended that all variations within the meaning and range of equivalents of the claims be encompassed within the present invention. Any reference signs in the claims should not be construed as limiting the claim to which they relate.

[0100] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A method for preparing BiOCl@PPy@PS-PEEK material with both antibacterial and bone nerve repair properties, characterized in that: The following steps are involved: S1. Dissolving bismuth nitrate pentahydrate and potassium chloride in water at certain concentrations to obtain a Bi(NO)3·5H2O solution and a KCl solution, respectively. Adding the KCl solution dropwise to the Bi(NO)3·5H2O solution, stirring magnetically and then performing a hydrothermal reaction to obtain BiOCl powder. S2. BiOCl powder was added to water at a certain concentration and magnetically stirred once. FeCl3·6H2O was then added and magnetically stirred twice. During the stirring process, Py monomer was added and magnetically stirred three times at room temperature. The resulting suspension was magnetically separated, repeatedly washed with water, and freeze-dried to obtain a BiOCl@PPy heterojunction. S3. The polyetheretherketone substrate was added to concentrated sulfuric acid and ultrasonicated for 5-10 minutes. The substrate was then added to acetone-water and repeatedly washed and dried to obtain S-PEEK with a porous surface structure. The sulfonated PEEK was added to a polydopamine solution, stirred and dried to obtain PS-PEEK. The BiOCl@PPy heterojunction solution was then added dropwise to the PS-PEEK surface multiple times and dried to obtain BiOCl@PPy@PS-PEEK. In step S2, the added concentration of the BiOCl powder is 0.01-0.02 mol / L; the mass ratio of the BiOCl powder, the Py monomer, and the FeCl3·6H2O is 1:1-1.15:0.65-0.

88.

2. The method for preparing the BiOCl@PPy@PS-PEEK material having both antibacterial and bone and nerve repair properties according to claim 1, characterized in that: In step S1, the added concentration of bismuth nitrate pentahydrate is 0.04-0.08 mol / L; the added concentration of potassium chloride is 0.08-0.12 mol / L; the magnetic stirring time is 1-2 h; the temperature of the hydrothermal reaction is 150-170° C., and the time is 4-6 h.

3. The method for preparing the BiOCl@PPy@PS-PEEK material having both antibacterial and bone and nerve repair properties according to claim 1, characterized in that: In step S2, the time of the first magnetic stirring is 20 to 50 minutes; the time of the second magnetic stirring is 20 to 50 minutes; the time of the third magnetic stirring is 20 to 24 hours; the temperature of the freeze-drying is -30 to -50°C, and the time is 20 to 24 hours.

4. The method for preparing the BiOCl@PPy@PS-PEEK material having both antibacterial and bone and nerve repair properties according to claim 1, characterized in that: In step S3, the concentration of the BiOCl@PPy heterojunction solution is 180-210 μg / mL.

5. The method for preparing the BiOCl@PPy@PS-PEEK material having both antibacterial and bone and nerve repair properties according to claim 1, characterized in that: In step S3, the number of washings is 2-4 times; the concentration of the polydopamine solution is 1-3 mg / mL; the stirring time is 20-24 h; and the number of dropwise additions is 4-7 times.

6. A BiOCl@PPy@PS-PEEK material with both antibacterial and bone and nerve repair properties, characterized by: Prepared by the preparation method according to any one of claims 1 to 5.

7. Use of the BiOCl@PPy@PS-PEEK material according to claim 6 in a hard tissue repair implant.

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