A polyvinyl alcohol-based composite material, its preparation method and application

Abstract

This invention relates to the field of polyvinyl alcohol (PVA) materials technology, specifically disclosing a PVA-based composite material, its preparation method, and its applications. This invention utilizes femtosecond laser technology to surface-treat a titanium alloy matrix, creating a unique micro / nano hierarchical structure on the titanium alloy surface. This enhances the bonding strength between the gel and the titanium alloy matrix. Furthermore, by introducing an appropriate amount of copper ions into a PVA-based polymer with a specific structure, a bioactive surface promoting osteoblast adhesion and proliferation is constructed. 2+ The introduction of this compound not only improves the biocompatibility and antibacterial properties of the material, but also avoids cytotoxic reactions and protein adsorption induced by high concentrations of metal ions, thereby achieving stable and long-lasting antibacterial effects and promoting the directed differentiation of osteoblasts. This polyvinyl alcohol-based composite material is expected to bring more reliable and lasting therapeutic effects to the clinical treatment of bone diseases and implant repair, and has broad application prospects in the field of bone repair implant materials.

Description

Technical Field

[0001] This invention relates to the field of polyvinyl alcohol materials technology, and in particular to a polyvinyl alcohol-based composite material, its preparation method, and its application. Background Technology

[0002] In recent years, with the increasing use of implants, the risk of implant-related infections has become increasingly prominent. Implants are highly susceptible to causing bacterial bone defects and chronic osteomyelitis. Osteomyelitis often occurs alongside bacterial infection and biofilm formation, leading to rupture of blood flow to the periosteum and intraosseous arterial system, ultimately resulting in osteonecrosis. Currently, the gold standard for treating osteomyelitis is a combination of local antibiotic delivery and systemic antibiotic therapy. However, biofilm formation limits the effectiveness of antibiotics, thus easily leading to disease relapse and making treatment difficult. Therefore, prevention has become a key clinical strategy.

[0003] Currently, while pure titanium and its alloys, widely used in clinical practice, possess excellent chemical stability, mechanical strength, corrosion resistance, and biocompatibility, they lack antibacterial properties, making them prone to bacterial infections, leading to secondary surgeries and significant resource consumption. Staphylococcus aureus is a major pathogen causing orthopedic implant infections. Despite extensive antibiotic research, resistance, especially multidrug resistance, is easily developed. Furthermore, researchers are dedicated to constructing coatings with immuno-osteogenic regulatory functions on implant surfaces to achieve both antibacterial and osteogenic effects. Although some progress has been made in orthopedic implant surface modification, the bonding strength of current coatings is insufficient, resulting in the inability to maintain biological function long-term. Therefore, there is an urgent clinical need for a novel method to prevent infection and promote tissue repair to address the challenges of implant-related infections. Summary of the Invention

[0004] To address the problem that insufficient bonding strength between the coating and the substrate in existing technologies leads to the inability to maintain the coating's function over a long period, this invention provides a polyvinyl alcohol-based composite material, its preparation method, and its application.

[0005] To solve the above-mentioned technical problems, the technical solution provided by the present invention is as follows:

[0006] In a first aspect, the present invention provides a polyvinyl alcohol-based composite material comprising a titanium alloy substrate treated by a femtosecond laser, wherein the titanium alloy substrate contains a gel coating of a polyvinyl alcohol-based polymer as shown in formula (I).

[0007]

[0008] Cu is coordinated to the terpyridine and catechol groups of the polyvinyl alcohol-based polymer. 2+ .

[0009] Compared to existing technologies, the polyvinyl alcohol-based composite material provided by this invention uses a femtosecond laser-treated titanium alloy as the substrate. Femtosecond laser treatment creates a unique micro / nano hierarchical structure on the titanium alloy surface, effectively increasing the contact area between the gel coating and the substrate, thereby significantly enhancing the bonding strength between the gel coating and the substrate. Simultaneously, a polyvinyl alcohol-based polymer with a specific structure is selected as the functional coating, wherein the polymer has a high content of catechol groups, which can improve the Cu... 2+ The grafting rate, and through the terpyridine group and catechol group with Cu 2+ The coordination effect of Cu 2+ Chelating and anchoring in polyvinyl alcohol polymers improves material stability and achieves Cu 2+ The long-lasting, slow release of nutrients achieves a sustained antibacterial effect; furthermore, by introducing specific amounts of terpyridine and catechol groups, the Cu content in the polyvinyl alcohol polymer can be controlled. 2+ The content of Cu, in appropriate amounts 2+ The introduction of [the substance] can not only improve the biocompatibility and antibacterial properties of the material, but also avoid cytotoxic reactions and protein adsorption induced by high concentrations of metal ions.

[0010] This invention introduces an appropriate amount of Cu into a polyvinyl alcohol-based polymer with a specific structure. 2+ It can be obtained through Cu 2+ The slow release of Cu provides a localized environment that promotes bone growth and has antibacterial properties. 2+ The introduction of [the substance] can further enhance the osteogenicity of polyvinyl alcohol-based composite materials by regulating the synthesis of extracellular matrix and cell differentiation, and has broad application prospects in the field of bone repair implant materials.

[0011] Furthermore, the thickness of the gel coating is 15nm to 25nm.

[0012] Furthermore, the preparation method of the polyvinyl alcohol-based polymer includes the following steps:

[0013] The compound shown in formula (II) and dopamine hydrochloride were subjected to an amidation reaction in a carboxyl activator and a reaction solvent to obtain the polyvinyl alcohol polymer shown in formula (I);

[0014]

[0015] Furthermore, in conjunction with the above-mentioned method for preparing polyvinyl alcohol-based polymers, the carboxyl activator is 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride.

[0016] Furthermore, in conjunction with the above-described method for preparing polyvinyl alcohol-based polymers, the reaction solvent is MES buffer.

[0017] For example, the MES buffer has a pH of 4.8 and a concentration of 0.1 mol / L.

[0018] Furthermore, in conjunction with the above-mentioned method for preparing polyvinyl alcohol-based polymers, the mass ratio of the compound shown in formula (II), the carboxyl activator, and dopamine hydrochloride is 5:12-14:12-14.

[0019] Preferably, the mass ratio of the compound represented by formula (II), the carboxyl activator, and dopamine hydrochloride is 5:13:13.

[0020] Preferably, the concentrations of the compound represented by formula (II), the carboxyl activator, and dopamine hydrochloride dissolved in the reaction solvent are 5–10 mg / mL, 13–26 mg / mL, and 13–26 mg / mL, respectively.

[0021] Furthermore, in conjunction with the above-mentioned method for preparing polyvinyl alcohol-based polymers, the amidation reaction temperature is 20℃~30℃, and the reaction time is 8h~12h.

[0022] It should be noted that after the reaction is completed, the reaction solution is dialyzed in deionized water for 3 days and then freeze-dried to obtain the polyvinyl alcohol-based polymer shown in formula (Ⅰ).

[0023] This invention introduces terpyridine and catechol groups into polyvinyl alcohol (PVA) molecules via a simple amidation reaction, effectively improving the antibacterial properties of PVA. Furthermore, the introduction of these groups enhances the adhesion of the implant to biological cells, improving its stability within bone tissue. Additionally, the terpyridine and catechol groups act as active groups, regulating the tissue microenvironment surrounding the implant and promoting more effective tissue repair and regeneration. Moreover, specific amounts of terpyridine and catechol groups also enhance the mechanical strength and toughness of the PVA-based gel, making it more suitable for the mechanical performance requirements of bone implants during use.

[0024] Furthermore, the preparation method of the compound represented by formula (II) includes the following steps:

[0025] The compound shown in formula (III) was subjected to an amidation reaction with 2,2':6',2”-terpyridine-4'-amine in a catalyst, a base and a reaction solvent to give the compound shown in (II);

[0026]

[0027] Furthermore, in conjunction with the preparation method of the compound shown in formula (II) above, the catalyst is 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride.

[0028] Furthermore, in conjunction with the preparation method of the compound shown in formula (II) above, the base is 4-dimethylaminopyridine, and the reaction solvent is dimethyl sulfoxide.

[0029] Furthermore, in conjunction with the preparation method of the compound shown in formula (II) above, the temperature of the amidation reaction is 20℃~30℃, and the reaction time is 8h~12h.

[0030] Furthermore, in conjunction with the preparation method of the compound shown in formula (II) above, the mass-to-volume ratio of the compound shown in formula (III) to the reaction solvent is 10 mg:1 mL to 20 mg:1 mL; the amount of 2,2':6',2”-terpyridine-4'-amine added is 17% to 28% of the mass of the compound shown in formula (II); the amount of catalyst added is 17% to 28% of the mass of the compound shown in formula (II); and the amount of base added is 6.5% to 22% of the mass of the compound shown in formula (II).

[0031] Furthermore, the preparation method of the compound represented by formula (II) includes the following steps:

[0032] Polyvinyl alcohol and succinic anhydride were esterified in a reaction solvent and an amine catalyst to obtain the compound shown in formula (III).

[0033] Furthermore, in conjunction with the preparation method of the compound shown in formula (II) above, the reaction solvent is dimethyl sulfoxide.

[0034] Furthermore, in conjunction with the preparation method of the compound shown in formula (II) above, the amine catalyst is triethylamine.

[0035] Furthermore, in conjunction with the preparation method of the compound shown in formula (II) above, the esterification reaction temperature is 20℃~30℃ and the reaction time is 8h~12h.

[0036] Furthermore, in conjunction with the preparation method of the compound shown in formula (II) above, the mass-to-volume ratio of polyvinyl alcohol to the reaction solvent is 1.5 mg:1 mL to 2.5 mg:1 mL; the volume ratio of the reaction solvent to triethylamine is 1:80 to 1:100; and the mass concentration of succinic anhydride dissolved in the reaction solvent is 0.84% ​​to 1.4%.

[0037] Specifically, the chemical reaction equation for preparing the polyvinyl alcohol-based polymer shown in formula (Ⅰ) of this invention is as follows:

[0038]

[0039]

[0040] The method for preparing polyvinyl alcohol-based polymers provided by this invention has a simple process route, mild operating conditions, and is suitable for large-scale industrial production applications, with good economic benefits and development prospects.

[0041] Secondly, the present invention also provides a method for preparing a polyvinyl alcohol-based composite material, characterized by comprising the following steps:

[0042] S1, dissolve the polyvinyl alcohol-based polymer shown in formula (Ⅰ) in water to obtain a polyvinyl alcohol-based polymer solution; mix the polyvinyl alcohol-based polymer solution with MOPs buffer solution evenly to obtain an impregnation solution;

[0043] S2, the titanium alloy substrate is pretreated by femtosecond laser. After treatment, it is cleaned to obtain the pretreated titanium alloy substrate.

[0044] S3, the pretreated titanium alloy matrix is ​​added to the impregnation solution, soaked, dried, then impregnated in copper solution, dried, to obtain polyvinyl alcohol-based composite material.

[0045] Furthermore, the concentration of the polyvinyl alcohol-based polymer solution is 2 mg / mL to 4 mg / mL.

[0046] Furthermore, the volume ratio of the polyvinyl alcohol-based polymer solution to the MOPs buffer solution is 1:1.5 to 1:2.5.

[0047] Furthermore, the MOPs buffer is Tris-MOPs-SDS electrophoresis buffer (20×, pH 8.3).

[0048] Furthermore, the processing frequency of the femtosecond laser is 610Hz to 630Hz, the power is 4.3Hz to 4.4Hz, the line spacing is 0.03μm to 0.05μm, and the velocity is 490 femtoseconds to 510 femtoseconds.

[0049] Furthermore, the immersion time in the impregnation solution is 10h to 14h.

[0050] Furthermore, the copper solution is a copper chloride solution.

[0051] Furthermore, the concentration of the copper chloride solution is 0.2 mg / mL to 0.5 mg / mL.

[0052] Furthermore, the immersion time in the copper solution is 1 hour to 1.5 hours.

[0053] This invention utilizes femtosecond laser technology to surface-treat a titanium alloy substrate, enhancing the bonding strength between the gel and the substrate. Furthermore, by introducing copper ions into a polyvinyl alcohol-based polymer with a specific structure, a bioactive surface is constructed that promotes osteoblast adhesion and proliferation. This achieves stable and long-lasting antibacterial properties and promotes directed osteoblast differentiation, potentially leading to more reliable and durable therapeutic effects in the clinical treatment of bone diseases and implant repair, with broad application prospects.

[0054] Thirdly, the present invention also provides the application of the above-mentioned polyvinyl alcohol-based composite material in the preparation of orthopedic implants.

[0055] The polyvinyl alcohol-based composite material provided by this invention has good safety and biocompatibility, exhibits long-lasting and excellent antibacterial activity against Gram-positive bacteria, and has a good ability to promote tissue repair. It is suitable for use in the preparation of orthopedic implants and has broad application value in the field of medical biotechnology. Attached Figure Description

[0056] Figure 1 The above is the 1H NMR spectrum of the PVA-TP-CA material prepared in Example 1 of this invention;

[0057] Figure 2 XPS spectra of the PVA-TP-CA / Cu@Ti sample prepared in Example 2 of this invention, where (a) is the full spectrum and (b) is Cu2p.

[0058] Figure 3 SEM images of the PVA-TP-CA material prepared in Example 1 and the PVA-TP-CA / Cu@Ti sample prepared in Example 2 of this invention are shown. Among them, (a) is the PVA-TP-CA material, (b) is a magnified view of the part marked by the red circle in (a), (c) is the PVA-TP-CA / Cu@Ti sample, and (d) is a magnified view of the part marked by the red circle in (c). The upper left corner of (a) and (b) is the hydrophobic contact angle test diagram of the corresponding materials.

[0059] Figure 4 This is a comparison diagram of the bonding strength between the PVA-TP-CA coating and the titanium alloy substrate in the PVA-TP-CA / Cu@Ti samples prepared in Example 2 and Comparative Example 1 of this invention;

[0060] Figure 5 This is a graph showing the cumulative release of copper ions in the PVA-TP-CA / Cu@Ti sample prepared in Example 2 of this invention.

[0061] Figure 6 Comparison of the proliferation of rat bone marrow mesenchymal stem cells in PVA-TP-CA / Cu@Ti samples prepared in different copper chloride solutions;

[0062] Figure 7 Comparison of antibacterial properties of PVA-TP-CA / Cu@Ti samples prepared in different copper chloride solutions. (A) shows the morphology of Staphylococcus aureus on different sample surfaces, (B) shows the morphology of Escherichia coli on different sample surfaces, (C) shows the comparison of antibacterial activity of different samples against Staphylococcus aureus, and (D) shows the comparison of antibacterial activity of different samples against Escherichia coli. Detailed Implementation

[0063] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0064] The polyvinyl alcohol (PVA) used in the following examples is polyvinyl alcohol 1799, manufactured by Aladdin; 2,2':6',2”-terpyridine-4'-amine (TP) is from Sinocare Research & Development Co., Ltd.; and dopamine hydrochloride is from McLean.

[0065] The titanium alloy substrate used in the following examples is a titanium sheet with a size of 10mm×10mm×1mm. Before use, the titanium sheet was polished with 600-grit and 1500-grit silicon carbide sandpaper respectively, and then rinsed with deionized water.

[0066] Example 1

[0067] A method for preparing a polyvinyl alcohol-based polymer includes the following steps:

[0068] Step a: Add 2.5g of polyvinyl alcohol to 100mL of dimethyl sulfoxide at 95℃, then add 1mL of triethylamine and 0.35g of succinic anhydride. Stir the resulting mixture at 95℃ for 30min, stir overnight at room temperature, then add the reaction solution to a dialysis bag with a molecular weight cutoff of 3.5kDa and dialyze with deionized water for one week. Freeze dry to obtain PVA-COOH.

[0069] Step b: Take 1g of the PVA-COOH prepared above, 0.28g of TP (2,2':6',2”-terpyridine-4'-amine), 0.17g of EDCI (1-ethyl-3-(3-dimethylpropyl)carbodiimide hydrochloride) and 0.112g of DMAP (4-dimethylaminopyridine) and add them to 100mL of dimethyl sulfoxide. Stir at 95℃ for 30min, stir at room temperature overnight, and then add the reaction solution to a dialysis bag with a molecular weight cutoff of 8.0kDa and dialyze with deionized water for 3 days. Freeze dry to obtain PVA-TP-COOH;

[0070] Step c: Add 0.3g of the above-prepared PVA-TP-COOH, 0.78g of EDCI, and 0.78g of dopamine hydrochloride to 30mL of 0.1mol / L MES buffer at pH 4.8, mix well, stir overnight at room temperature, add the reaction solution to a dialysis bag with a molecular weight cutoff of 8.0kDa, dialyze with deionized water for 3 days, and freeze-dry to obtain PVA-TP-CA.

[0071] The chemical reaction equations for the above reactions are as follows:

[0072]

[0073]

[0074] The reaction raw materials of the above substances can also be replaced with other proportions specified in this specification, and the reaction temperature and time can also be replaced with other conditions specified in this specification. As long as they are within the range specified in this specification, PVA-TP-CA with the same structure and performance can be obtained.

[0075] Example 2

[0076] This embodiment provides a method for preparing a polyvinyl alcohol-based composite material, including the following steps:

[0077] S1, PVA-TP-CA prepared in Example 1 is added to deionized water to obtain a PVA-TP-CA solution with a concentration of 3 mg / mL; the PVA-TP-CA solution is mixed with MOPs buffer at a volume ratio of 1:2 to obtain an impregnation solution;

[0078] S2. The titanium alloy substrate was treated using femtosecond laser technology. The frequency of the femtosecond laser was 620Hz, the power was 4.35Hz, the line spacing was 0.04μm, and the speed was 500 femtoseconds. After the treatment, the titanium alloy substrate was cleaned with 75% alcohol and dried to obtain the pretreated titanium alloy substrate.

[0079] S3, the pretreated titanium alloy substrate is added to the above impregnation solution and soaked at room temperature for 12 hours, then dried at room temperature, and then added to a 0.5 mg / mL copper chloride solution and soaked for 1 hour, and dried at room temperature to obtain a titanium alloy substrate with a PVA-TP-CA coating, denoted as PVA-TP-CA / Cu@Ti.

[0080] Example 3

[0081] This embodiment provides a method for preparing a polyvinyl alcohol-based composite material, including the following steps:

[0082] S1, PVA-TP-CA prepared in Example 1 is added to deionized water to obtain a PVA-TP-CA solution with a concentration of 2 mg / mL; the PVA-TP-CA solution is mixed with MOPs buffer at a volume ratio of 1:1.5 to obtain an impregnation solution;

[0083] S2. The titanium alloy substrate was treated using femtosecond laser technology. The frequency of the femtosecond laser was 610 Hz, the power was 4.3 Hz, the line spacing was 0.03 μm, and the speed was 490 femtoseconds. After the treatment, the titanium alloy substrate was cleaned with 75% alcohol and dried to obtain the pretreated titanium alloy substrate.

[0084] S3, the pretreated titanium alloy substrate is added to the above impregnation solution and soaked at room temperature for 14 hours, then dried at room temperature, and then added to a 0.2 mg / mL copper chloride solution and soaked for 1.5 hours, and dried at room temperature to obtain a titanium alloy substrate with a PVA-TP-CA coating, denoted as PVA-TP-CA / Cu@Ti.

[0085] Example 4

[0086] This embodiment provides a method for preparing a polyvinyl alcohol-based composite material, including the following steps:

[0087] S1, PVA-TP-CA prepared in Example 1 is added to deionized water to obtain a PVA-TP-CA solution with a concentration of 4 mg / mL; the PVA-TP-CA solution is mixed with MOPs buffer at a volume ratio of 1:2.5 to obtain an impregnation solution;

[0088] S2. The titanium alloy substrate was treated using femtosecond laser technology. The frequency of the femtosecond laser was 630 Hz, the power was 4.4 Hz, the line spacing was 0.05 μm, and the speed was 510 femtoseconds. After the treatment, the titanium alloy substrate was cleaned with 75% alcohol and dried to obtain the pretreated titanium alloy substrate.

[0089] S3, the pretreated titanium alloy substrate is added to the above impregnation solution and soaked at room temperature for 10 hours, then dried at room temperature, and then added to a 0.5 mg / mL copper chloride solution and soaked for 1 hour, and dried at room temperature to obtain a titanium alloy substrate with a PVA-TP-CA coating, denoted as PVA-TP-CA / Cu@Ti.

[0090] Comparative Example 1

[0091] This comparative example provides a method for preparing a polyvinyl alcohol-based composite material, which differs from Example 2 only in that the femtosecond laser treatment step on the titanium alloy substrate is omitted. The specific steps are as follows:

[0092] S1, PVA-TP-CA prepared in Example 1 is added to deionized water to obtain a PVA-TP-CA solution with a concentration of 3 mg / mL; the PVA-TP-CA solution is mixed with MOPs buffer at a volume ratio of 1:2 to obtain an impregnation solution;

[0093] S2, the titanium alloy substrate is added to the above impregnation solution and soaked at room temperature for 12 hours, then dried at room temperature, and then added to a 0.5 mg / mL copper chloride solution and soaked for 1 hour, and dried at room temperature to obtain a titanium alloy substrate with a PVA-TP-CA coating.

[0094] Characterization

[0095] Figure 1 The image shows the 1H NMR spectrum of the PVA-TP-CA material prepared in Example 1. As can be seen from the image, the chemical shifts of the TP groups are mainly concentrated between 7.0 ppm and 9.0 ppm, while the chemical shifts of the CA groups are mainly concentrated between 6.0 ppm and 7.0 ppm, indicating that TP and CA were successfully grafted onto the polyvinyl alcohol molecular chain.

[0096] XPS plot of PVA-TP-CA / Cu@Ti prepared in Example 2 is shown below. Figure 2 As shown. From Figure 2 As shown in (a), the binding energy of Cu2p in the PVA-TP-CA / Cu coating is 932.6 eV. From... Figure 2 As can be seen in (b), the satellite peaks of copper ions in the 2P orbital are mainly located at 943 eV and 961 eV, proving that copper ions have been grafted into the coating.

[0097] SEM images of the PVA-TP-CA material prepared in Example 1 and the PVA-TP-CA / Cu@Ti material prepared in Example 2 are shown below. Figure 3 As shown in the figure, the grafting of copper ions increases the roughness of the copper alloy substrate. Furthermore, it is well known that titanium alloys have poor hydrophilicity, while... Figure 3 (a) and Figure 3 (b) The contact angle test in the upper left corner shows that the introduction of the coating on the titanium alloy substrate significantly improves the hydrophilicity of the substrate, and the hydrophilicity is also improved to a certain extent after grafting copper ions, which is conducive to promoting cell adhesion, improving the bonding force between the implant and the surrounding bone tissue, and accelerating the bone healing process.

[0098] Performance testing

[0099] 1. Bond strength

[0100] The bonding strength of the coating was tested using the tensile test. According to ISO 13779.2, 3M DP460 adhesive with high bonding strength was selected, along with two titanium rods with a diameter of 1 mm and a length of 5 cm. The titanium rods with double-sided coating were bonded between the cross sections of the two titanium rods using 3M DP460 adhesive, and tensile testing was performed using a mechanical testing machine at a tensile rate of 1 mm / min.

[0101] The test results of the titanium alloy substrates with PVA-TP-CA coatings prepared in Example 2 and Comparative Example 1 are as follows: Figure 4 As shown.

[0102] As shown in the figure, the adhesion strength between the PVA-TP-CA coating and the titanium alloy substrate in the sample prepared in Example 2 is 29.04 MPa, while the adhesion strength between the PVA-TP-CA coating and the titanium alloy substrate in the sample prepared in Comparative Example 1 is 38.8 MPa. This demonstrates that the adhesion strength between the titanium alloy substrate and the PVA-TP-CA coating is significantly enhanced after femtosecond laser treatment.

[0103] 2. Release of copper ions

[0104] The PVA-TP-CA / Cu@Ti (10mm×10mm×1mm) samples prepared in Example 2 were immersed in 5 mL of phosphate buffer (pH 7.4). Three parallel groups were established for each sample. Copper ion concentration was measured at 1, 2, 3, 6, 7, 8, 9, and 12 days, and the buffer was replaced with fresh PBS. Copper ion concentration was detected using inductively coupled plasma optical emission spectrometry (ICP-MS), and the results are shown in Table 1. Figure 5 As stated above.

[0105] Table 1 Copper ion release

[0106] Release amount (ppb) RSD / % of three sample groups 1d 13.534 3.11 2d 27.143 2.114 3d 36.133 4.543 6d 36.244 2.311 7d 39.381 3.243 8d 48.948 8.261 9d 50.108 8.978 12d 62.293 5.768

[0107] This demonstrates that the PVA-TP-CA / Cu@Ti sample prepared in the embodiments of the present invention can achieve the slow release of copper ions, thereby achieving the effects of long-lasting antibacterial activity and promoting tissue repair.

[0108] 3. Promotes cell proliferation

[0109] The PVA-TP-CA prepared in Example 1 was immersed in copper chloride solutions of different concentrations, namely 0.1 mg / mL, 0.2 mg / mL, 0.5 mg / mL and 1 mg / mL, and PVA-TP-CA / Cu@Ti samples were prepared in the same manner as in Example 2.

[0110] Each prepared sample was placed in a 24-well plate, and rat bone marrow mesenchymal stem cells (BMSCs) were seeded onto the coating surface of each sample, with 1.5 × 10⁻⁶ cells seeded per well. 4 Samples were cultured at 37℃ for 1 day and 3 days, respectively. After culture, the samples were transferred to new 24-well plates and gently washed three times with PBS buffer for 5 minutes each time. CCK-8 and complete culture medium were mixed at a volume ratio of 1:9, and 1 mL of the mixture was added to each well. The plates were then incubated at 37℃ in the dark for 2.5 hours. 100 μL of the resulting solution was then transferred to a 96-well plate, and the absorbance of each sample solution was measured using a microplate reader at a wavelength of 450 nm. The results are shown in Table 2 and 3. Figure 6 As shown.

[0111] Table 2. Cell proliferation of rat bone marrow mesenchymal stem cells in PVA-TP-CA / Cu@Ti samples prepared with copper chloride solutions of different concentrations.

[0112]

[0113] 4. Antibacterial properties

[0114] The PVA-TP-CA / Cu@Ti test samples prepared in copper chloride solutions of different concentrations were placed in a 24-well plate with the coated side facing up. In a clean bench, 1 mL of a 1×10⁻⁶ solution was pipetted onto the plate. 8 Staphylococcus aureus at a concentration of CFU / mL and 1×10 6 CFU / mL of *E. coli* was added to the surface of each group of samples. After incubating the plates at 37℃ for 24 hours, the bacterial suspension in each well was collected. The antibacterial rate of each group of samples was detected and calculated using serial dilution and plate count methods. 100 μL of serially diluted bacterial suspension was evenly spread onto agar plates and incubated at 37℃ for 24 hours. After removing the plates, plates with colony counts between 30 and 300 were selected, and the number of colonies grown on the plates was counted. The number of viable bacteria in the surrounding culture medium was then calculated based on the dilution factor. The results are as follows: Figure 7 As shown in Table 3.

[0115] Table 3. Performance of PVA-TP-CA / Cu@Ti samples against Staphylococcus aureus and Escherichia coli.

[0116]

[0117] As can be seen from the results, the PVA-TP-CA / Cu@Ti sample prepared in the embodiments of the present invention has excellent anti-Staphylococcus aureus and antibacterial effects. Considering both cell proliferation and antibacterial effects, the PVA-TP-CA / Cu@Ti sample prepared in 0.5 mg / mL copper chloride solution has the best performance.

[0118] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A polyvinyl alcohol-based composite material, characterized in that, The titanium alloy substrate includes a femtosecond laser-treated titanium alloy substrate, on which a gel coating of a polyvinyl alcohol-based polymer of formula (I) is contained; Equation (I) Cu is coordinated to the terpyridine and catechol groups of the polyvinyl alcohol-based polymer. 2+ ; The preparation method of the polyvinyl alcohol-based polymer includes the following steps: The compound shown in formula (III) was subjected to an amidation reaction with 2,2':6',2''-terpyridine-4'-amine in a catalyst, a base and a reaction solvent to give the compound shown in (II); The compound shown in formula (II) and dopamine hydrochloride were subjected to an amidation reaction in a carboxyl activator and a reaction solvent to obtain the polyvinyl alcohol polymer shown in formula (I).

2. The polyvinyl alcohol-based composite material as described in claim 1, characterized in that, The thickness of the gel coating is 15nm~25nm.

3. The polyvinyl alcohol-based composite material as described in claim 1, characterized in that, The carboxyl activator is 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride; The reaction solvent is MES buffer; The mass ratio of the compound represented by formula (II), the carboxyl activator, and dopamine hydrochloride is 5:12~14:12~14; The amidation reaction is carried out at a temperature of 20°C to 30°C for 8 to 12 hours.

4. The polyvinyl alcohol-based composite material as described in claim 1, characterized in that, The catalyst is 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride; The base is 4-dimethylaminopyridine; The reaction solvent is dimethyl sulfoxide; The amidation reaction is carried out at a temperature of 20°C to 30°C for 8 to 12 hours.

5. The polyvinyl alcohol-based composite material as described in claim 1, characterized in that, The preparation method of the compound shown in formula (Ⅲ) includes the following steps: Polyvinyl alcohol and succinic anhydride were esterified in a reaction solvent and an amine catalyst to obtain the compound shown in formula (III).

6. The polyvinyl alcohol-based composite material as described in claim 5, characterized in that, The reaction solvent is dimethyl sulfoxide; The amine catalyst is triethylamine; The esterification reaction is carried out at a temperature of 20℃~30℃ for 8h~12h.

7. The method for preparing the polyvinyl alcohol-based composite material according to any one of claims 1 to 6, characterized in that, Includes the following steps: S1, dissolve the polyvinyl alcohol-based polymer shown in formula (Ⅰ) in water to obtain a polyvinyl alcohol-based polymer solution; mix the polyvinyl alcohol-based polymer solution with MOPs buffer solution evenly to obtain an impregnation solution; S2, the titanium alloy substrate is pretreated by femtosecond laser. After treatment, it is cleaned to obtain the pretreated titanium alloy substrate. S3, the pretreated titanium alloy matrix is ​​added to the impregnation solution, soaked, dried, then impregnated in a copper salt solution, dried, to obtain a polyvinyl alcohol-based composite material.

8. The use of the polyvinyl alcohol-based composite material according to any one of claims 1 to 6 in the preparation of orthopedic implants.

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