A programmable drug release anti-infective and osteoinductive multifunctional orthopedic endosseous implant device and method of making same

Abstract

The application discloses a programmable drug release anti-infection and bone formation promoting multifunctional orthopedic internal implant device and a preparation method thereof. The implant is prepared according to the following steps: 1) introducing a titanium nanotube (TNT) structure on the surface of a titanium alloy base by using an anodic oxidation method; 2) sequentially loading an anti-infection component, a bone formation promoting factor and a blood vessel formation promoting factor into the TNT tube by using a vacuum sequential loading process; and 3) finally, coating a poly-tannic acid (PTA) coating on the surface of the material base by using a tannic acid (TA) in-situ self-polymerization technology. The multifunctional bone implant device can sequentially release the anti-infection drug, the blood vessel formation promoting factor and the bone formation promoting factor in the order of the vacuum drug loading, and the modified surface of the device has good drug release and oxidation resistance, so that the bone infection can be efficiently prevented and treated, and the bone repair efficiency is improved.

Description

Technical Field

[0001] This invention belongs to the field of orthopedic implant preparation, and relates to an implant device and its preparation method, particularly to a programmable drug-release anti-infection / osteopromoting multifunctional orthopedic implant device and its preparation method. Background Technology

[0002] In today's society, the number of orthopedic trauma patients continues to rise, leading to a growing clinical demand for internal fixation materials for fractures. Traditional internal fixation materials suffer from poor bioactivity, long postoperative healing times, and relatively high perioperative infection rates. Postoperative infection is one of the most common complications in orthopedics, potentially leading to repair failure, high subsequent treatment costs, a high rate of reoperation, and unsatisfactory postoperative outcomes. Therefore, developing a new type of implant to address these issues is urgently needed.

[0003] Tissue engineering technology has flourished in recent years, and various novel orthopedic implants have shown great clinical application potential in the field of fracture fixation. However, very few multifunctional implants are currently used clinically. Most implants can only perform the most basic fixation function and are unable to address issues such as infection prevention and bone promotion. Even with the few multifunctional implants available, the drug release process is highly uncontrollable and difficult to match with the physiological osteogenic cycle, leading to problems such as early infiltration of large numbers of inflammatory cells, limited formation of the osteogenic microenvironment, delayed bone repair, and late-stage secondary infection. At the same time, drug loading on the implant surface is difficult. Common methods include ultrasonic loading and adsorption, but these generally suffer from low drug loading efficiency and poor drug loading consistency.

[0004] To address the aforementioned issues, this invention designs a multifunctional orthopedic implant based on a vacuum sequential loading process, which combines anti-infection and osteogenic properties. The PTA coating on the implant surface simultaneously provides antioxidant and physical shielding effects, enhancing biocompatibility and preventing biofilm formation while enabling sustained drug release. The longitudinal structure of the titanium nanotubes allows for top-down sequential drug release, which is compatible with the physiological osteogenic process, thus achieving effective postoperative anti-infection and efficient osteogenic effects. Summary of the Invention

[0005] The purpose of this invention is to address the problems of poor anti-infection ability and weak osteogenic ability of ordinary internal fixation implants. By combining the characteristics of materials such as TC4 titanium alloy, titanium dioxide nanotubes, and tannic acid (TA), this invention provides a multifunctional orthopedic implant device with programmed drug release for anti-infection and osteogenic purposes, as well as its preparation method.

[0006] This invention is achieved using the following technical solution:

[0007] The present invention discloses a method for preparing a programmable drug-release anti-infective / osteogenic multifunctional orthopedic implant, comprising the following steps:

[0008] (1) Remove the oxide film on the surface of the titanium alloy substrate, clean it with ultrasound, and then perform anodizing treatment on the cleaned titanium alloy substrate to obtain a titanium alloy substrate material containing titanium nanotubes (TNT); prepare a bone-promoting vacuum loading solution, a blood vessel-promoting vacuum loading solution, and an anti-infection vacuum loading solution.

[0009] (2) The titanium alloy substrate material containing titanium nanotubes (TNT) was sequentially placed in a bone-promoting vacuum loading solution, a blood vessel-promoting vacuum loading solution, and an anti-infection vacuum loading solution for vacuum sequential loading, resulting in a multifunctional material containing bone-promoting components, blood vessel-promoting components, and anti-infection components in the TNT tubes from bottom to top.

[0010] (3) The multifunctional material is placed in Tris-HCl containing tannic acid (TA) and shaken for 12-72 hours to achieve in-situ self-polymerization of TA and form a polytannic acid (PTA) coating on the surface of the multifunctional material. After cleaning, encapsulation and irradiation sterilization, an anti-infection / osteopromoting multifunctional orthopedic implant based on vacuum sequential loading process is obtained.

[0011] Furthermore, in step (1), the method for removing the oxide film on the surface of the titanium alloy substrate is as follows: the titanium alloy substrate is polished in sequence with sandpaper or grinding wheel with mesh sizes of 120, 320, 600 and 800 to remove the oxide film on the surface and obtain a smooth surface; the ultrasonic cleaning is performed by placing the substrate in acetone, anhydrous ethanol and deionized water in sequence for ultrasonic cleaning, with a cleaning power of 80-100w and a cleaning time of 15-30min.

[0012] Furthermore, the method is characterized in that, in step (1), the anodizing process includes: placing the cleaned titanium alloy substrate in an electrolytic cell for anodizing, wherein the anode in the electrolytic cell is a titanium alloy sample, the cathode is a titanium plate, the electrode spacing is 15-25 cm, the voltage is 15-25 V, the electrolyte solvent is composed of deionized water, glycerol and ethylene glycol in a 2:1:1 ratio, the electrolyte solute is 1-2 wt% sulfuric acid, 1-5 wt% hydrofluoric acid and 0.25-0.75 wt% sodium dodecyl sulfate; and the electrolysis time is 1-4 h.

[0013] Furthermore, the electrolyte level must be sufficient to completely submerge the titanium alloy substrate during each anodizing process, and the electrolyte needs to be replaced when the current is less than 0.02A.

[0014] Furthermore, in step (1), the pore size of the titanium nanotubes (TNT) is 80-120 nm.

[0015] Furthermore, the bone-promoting vacuum loading solution is a mixed solution of bone-promoting polypeptide / sodium alginate / glycerol / deionized water, wherein the bone-promoting polypeptide is one or more of BMP-2, bone growth peptide OGP, BMP-7, and TGF-β, with a concentration of 10-50 μg / ml; the sodium alginate concentration is 0.25-0.75 wt%, and the viscosity is >0.002 Pas; the glycerol concentration is 0.25-2.5 wt%, and the remainder is deionized water;

[0016] The aforementioned angiogenic vacuum loading solution is a mixed solution of angiogenic peptide / sodium alginate / glycerol / deionized water, wherein the angiogenic peptide is one or more of α-FGF, β-FGF, PD-ECGF, TGF, TNF, and VEGF, with a concentration of 5-50 μg / ml; the sodium alginate concentration is 0.25-0.75 wt%, and the viscosity is >0.002 Pas; the glycerol concentration is 0.25-2.5 wt%, and the remainder is deionized water;

[0017] The anti-infective vacuum-loaded solution is a 5wt% commercial povidone-iodine solution / povidone-iodine powder / sodium alginate / glycerol mixed solution, wherein the concentration of povidone-iodine powder is 1-10wt%; the concentration of sodium alginate is 0.25-0.75wt% and the viscosity is >0.002Pas; the concentration of glycerol is 0.5-5wt% and the remainder is 5wt% commercial povidone-iodine solution.

[0018] Furthermore, in step (2), the specific steps of the vacuum sequential loading include:

[0019] 1) Place the titanium alloy substrate material containing titanium nanotubes (TNT) into a bone-promoting vacuum loading solution for vacuum loading. The resulting product is washed with deionized water and dried in a forced-air dryer at 25-35°C for 24-72 hours. This process can be repeated 3-10 times to ensure sufficient loading and obtain a material containing bone-promoting components.

[0020] 2) Place the material containing bone-promoting components obtained in step 1) into a vascular-promoting vacuum loading solution for vacuum loading. Wash the resulting product with deionized water and dry it in a forced-air drying at 25-35℃ for 6-24 hours. This process can be repeated 3-10 times to ensure sufficient loading, thereby obtaining a material containing both bone-promoting and vascular-promoting components.

[0021] 3) Place the material containing bone-promoting and angiogenesis-promoting components obtained in step 2) into an anti-infective vacuum loading solution for vacuum loading. Rinse the resulting product with deionized water and dry it in a forced-air drying environment at 25-35°C for 6-24 hours. This process can be repeated 3-10 times to ensure sufficient loading. This yields a multifunctional material containing bone-promoting, angiogenesis-promoting, and anti-infective components sequentially from bottom to top inside the TNT tube.

[0022] Furthermore, the vacuum load has a vacuuming time of 5-30 min, a vacuum degree of 1-100 Pa, and a pressure holding time of 2-20 min;

[0023] Furthermore, in step (3), the pH of the Tris-HCl containing tannic acid (TA) is 8.5, and the TA content is 2-16 mg / ml; the shaking rate is 40-120 rpm, and the reaction temperature is 25-37℃.

[0024] The beneficial effects of this invention are as follows:

[0025] 1) The implant described in this invention uses TC4 titanium alloy, osteogenic polypeptide, angiogenic polypeptide, povidone-iodine, sodium alginate, tannic acid (TA) and other main raw materials as a combination of processes such as anodizing, vacuum sequential loading and in-situ self-polymerization.

[0026] 2) This invention introduces a longitudinally semi-sealed nanotube structure onto the surface of a titanium alloy substrate through anodizing. This nanotube, with its high aspect ratio tubular structure, is suitable for efficient drug loading, providing feasibility for vacuum loading processes. Simultaneously, this invention innovatively introduces a vacuum loading process, overcoming the problem of high surface tension at the nanotube openings, which hinders drug loading. This method is also cost-effective and offers strong controllability. Different drug loading amounts can be customized by adjusting parameters such as loading time, loading cycles, and vacuum level, enabling customizable implants. Furthermore, the drug loading efficiency and stability of the vacuum loading method are significantly superior to traditional loading methods, greatly increasing implant production efficiency. This invention innovatively combines traditional anodizing with vacuum sequential loading technology, achieving innovative application of the process.

[0027] 3) This invention further utilizes the controllable order of drug loading in sequential vacuum loading to achieve "sequential loading and reverse release" of drugs. Based on the longitudinal semi-sealed tube structure of the nanotube and the controllability of the vacuum loading order, the drug loading order is from bottom to top (from bottom to top: osteogenic factor, angiogenic factor, anti-infective factor), and the release order is from top to bottom (from front to back: anti-infective factor, angiogenic factor, osteogenic factor). This adapts the implant to the timing of infection and the physiological osteogenic process: the antibacterial components released initially on the surface exert a significant anti-infective effect, followed by the release of angiogenic peptides to promote angiogenesis and provide the necessary microenvironment for osteogenic formation; the osteogenic factor located at the bottom of the nanotube is released relatively late, starting to exert its effect after the local osteogenic microenvironment has been basically formed, and its effect lasts for a longer period, exerting its effect throughout the entire osteogenic process. This invention leverages the advantages of the vacuum sequential loading process, endowing multiple active components with a stacked structure, achieving organic synergy between the functions of the active components from a temporal perspective, which is significantly innovative.

[0028] 4) The PTA coating layer on the surface of this invention has good antioxidant and antibacterial adhesion effects. Its antioxidant capacity can improve the oxygen free radical (ROS) response caused by neutrophil infiltration in the early stages of implantation, reducing tissue damage. Its antibacterial adhesion effect can inhibit the formation of bacterial biofilms, further enhancing its anti-infection ability. Simultaneously, the PTA coating layer and sodium alginate can jointly form a physical barrier, playing a synergistic role. This can significantly improve the cytotoxicity problem caused by the initial burst release of antibacterial drugs, while prolonging the action time of various components to achieve long-lasting and sustained-release effects, matching the longer cycle of physiological osteogenic processes.

[0029] 5) This invention has a five-layer sequential structure from bottom to top: titanium nanotubes, three active ingredients (osteogenic factor, angiogenic factor, and anti-infective drug), and a surface PTA coating layer. The bottom titanium nanotubes are the basic structure for efficient drug loading; the osteogenic factor, angiogenic factor, and anti-infective drug work synergistically to promote the formation of an early osteogenic microenvironment and long-term osteogenic promotion; the surface PTA coating layer improves biocompatibility and simultaneously provides sustained-release and anti-infective effects. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of a programmable drug-release anti-infection / osteopromoting multifunctional orthopedic implant device in an embodiment of the present invention.

[0031] Figure 2 This is a SEM image of the TNT structure on the titanium alloy surface in an embodiment of the present invention;

[0032] Figure 3 This is a SEM image of the active component after vacuum sequential loading of TNT in an embodiment of the present invention;

[0033] Figure 4 This is a SEM image of the surface structure of the anti-infection / osteopromoting multifunctional orthopedic implant device in an embodiment of the present invention;

[0034] Figure 5 The release curves of the antibacterial active ingredient, the angiogenic active ingredient, and the osteogenic active ingredient in Example 2 of the present invention are shown (using a 1cm*1cm*0.2cm TC4 metal sheet, placed in 3ml PBS solution, and extracts at different time points were diluted with deionized water to 1 / 1000 and then detected by ICP-MS). Detailed Implementation

[0035] The technical solution of the present invention will be clearly and thoroughly described below with reference to specific examples and accompanying drawings.

[0036] A schematic diagram of the multifunctional orthopedic implant device with programmable drug delivery for anti-infection and osteopromoting effects of the present invention is shown below. Figure 1 As shown, it has a five-layer sequential structure from bottom to top: titanium nanotubes, three active ingredients (osteogenic factor, angiogenic factor, and anti-infective drug), and a PTA coating layer on the surface.

[0037] Example 1

[0038] ①The titanium alloy substrate was polished with sandpaper of 120, 320, 600 and 800 grit in sequence to remove the oxide film on the surface and obtain a smooth surface. Then it was ultrasonically cleaned in acetone, anhydrous ethanol and deionized water for 15 minutes in sequence.

[0039] ② The cleaned titanium alloy substrate was placed in an electrolytic cell for anodizing treatment. The electrode spacing was 20 cm, the voltage was 20 V, and the electrolyte consisted of deionized water, glycerol, and ethylene glycol in a volume ratio of 2:1:1. The electrolyte solutes were 2 wt% sulfuric acid, 5 wt% hydrofluoric acid, and 0.75 wt% sodium dodecyl sulfate. The anodizing time was 4 h. The SEM image of the resulting structure is shown below. Figure 2 As shown;

[0040] ③ Prepare vacuum-loaded solution media with bone-promoting / angiogenic / anti-infection functions: The bone-promoting solution media is a mixed solution of bone-promoting peptide / sodium alginate / glycerol / deionized water, wherein the bone-promoting peptide is BMP-2 with a concentration of 30 μg / ml; the sodium alginate concentration is 0.5 wt% with a viscosity > 0.002 Pas; and the glycerol concentration is 2 wt%. The angiogenic solution media is a mixed solution of angiogenic peptide / sodium alginate / glycerol / deionized water, wherein the angiogenic peptide is VEGF with a concentration of 30 μg / ml; the sodium alginate concentration is 0.5 wt% with a viscosity > 0.002 Pas; and the glycerol concentration is 2 wt%. The anti-infection solution media is a 5 wt% commercial povidone-iodine solution / povidone-iodine powder / sodium alginate / glycerol mixed solution, wherein the povidone-iodine powder concentration is 10 wt%; the sodium alginate concentration is 0.5 wt% with a viscosity > 0.002 Pas; and the glycerol concentration is 3 wt%.

[0041] ④ The anodized titanium alloy substrate material from step ② was sequentially placed in the above-mentioned bone-promoting vacuum loading solution medium, blood vessel-promoting vacuum loading solution medium, and anti-infection vacuum loading solution medium for cyclic vacuum loading. The vacuuming time was 30 min, the vacuum degree was 100 Pa, and the holding time was 20 min. Each step of the anti-infection, blood vessel-promoting, and bone-promoting solution medium vacuum loading was repeated 5 times to ensure sufficient loading. After each vacuum loading, the sample surface was rinsed three times with deionized water to remove residual vacuum loading solution medium. After vacuum loading with the anti-infection solution medium, the sample was dried at 35°C for 24 hours, and after vacuum loading with the blood vessel-promoting and bone-promoting solution media, the sample was dried at 35°C for 6 hours. The resulting structure is shown below. Figure 3 As shown;

[0042] ⑤ Place the material from step ④ in Tris-HCl (pH=8.5) containing TA (4 mg / ml) and shake at 80 rpm for 24 h;

[0043] ⑥ After cleaning, packaging, and irradiation sterilization, the desired anti-infection / osteopromoting multifunctional orthopedic implant device based on vacuum sequential loading process is obtained. Its surface structure is as follows: Figure 4 As shown;

[0044] ⑦ SEM analysis of the above materials showed that the average diameter of the titanium nanotubes was approximately 114 nm. The maximum release rates of iodine ions, angiogenic peptides, and osteogenic peptides appeared at approximately 5 days, 7 days, and 21 days, respectively. CCK-8 assay of the extract of the material showed a relative cell activity of 89% and a 24-hour antibacterial rate of 97%.

[0045] Example 2

[0046] ①The titanium alloy substrate was polished with sandpaper of 120, 320, 600 and 800 grit in sequence to remove the oxide film on the surface and obtain a smooth surface. Then it was ultrasonically cleaned in acetone, anhydrous ethanol and deionized water for 15 minutes in sequence.

[0047] ② The cleaned titanium alloy substrate was placed in an electrolytic cell for anodizing treatment. The electrode spacing was 20 cm, the voltage was 15 V, and the electrolyte consisted of deionized water, glycerol and ethylene glycol in a volume ratio of 2:1:1. The electrolyte solutes were 2 wt% sulfuric acid, 5 wt% hydrofluoric acid and 0.75 wt% sodium dodecyl sulfate. The electrolysis time was 4 h.

[0048] ③ Prepare vacuum-loaded solution media with bone-promoting / angiogenic / anti-infection functions: The bone-promoting solution media is a mixed solution of bone-promoting peptide / sodium alginate / glycerol / deionized water, wherein the bone-promoting peptide is BMP-2 with a concentration of 30 μg / ml; the sodium alginate concentration is 0.5 wt% with a viscosity > 0.002 Pas; and the glycerol concentration is 2 wt%. The angiogenic solution media is a mixed solution of angiogenic peptide / sodium alginate / glycerol / deionized water, wherein the angiogenic peptide is VEGF with a concentration of 30 μg / ml; the sodium alginate concentration is 0.5 wt% with a viscosity > 0.002 Pas; and the glycerol concentration is 2 wt%. The anti-infection solution media is a 5 wt% commercial povidone-iodine solution / povidone-iodine powder / sodium alginate / glycerol mixed solution, wherein the povidone-iodine powder concentration is 10 wt%; the sodium alginate concentration is 0.5 wt% with a viscosity > 0.002 Pas; and the glycerol concentration is 3 wt%.

[0049] ④ The anodized titanium alloy substrate material from step ② was sequentially placed in the above-mentioned bone-promoting vacuum loading solution medium, blood vessel-promoting vacuum loading solution medium, and anti-infection vacuum loading solution medium for cyclic vacuum loading. The vacuuming time was 30 min, the vacuum degree was 100 Pa, and the holding time was 20 min. Each step of vacuum loading in the anti-infection, blood vessel-promoting, and bone-promoting solution media was repeated 5 times to ensure sufficient loading. After each vacuum loading, the sample surface was rinsed three times with deionized water to remove residual vacuum loading solution medium. After vacuum loading in the anti-infection solution medium, the sample was dried at 35°C for 24 hours, and after vacuum loading in the blood vessel-promoting and bone-promoting solution media, the sample was dried at 35°C for 6 hours.

[0050] ⑤ Place the material from step ④ in Tris-HCl (pH=8.5) containing TA (4 mg / ml) and shake at 80 rpm for 24 h;

[0051] ⑥ After cleaning, packaging, and irradiation sterilization, the desired anti-infection / osteopromoting multifunctional orthopedic implant device based on vacuum sequential loading process is obtained.

[0052] ⑦ The release curves of the antibacterial active ingredient, the pro-angiogenic active ingredient, and the pro-osteogenic active ingredient in this example are as follows: Figure 5 As shown, compared to Example 1, the voltage during anodizing was reduced. SEM analysis of the above material showed that the average diameter of the titanium nanotubes was approximately 82 nm. The reduced diameter led to a decrease in drug loading, with the total iodine release reduced to 63% of that in Example 1, the total release of angiogenic peptides reduced to 55% of that in Example 1, and the total release of bone-promoting peptides reduced to 71% of that in Example 1. At the same time, the release rate decreased, with the main release phases occurring at approximately 7 days, 14 days, and 28 days, respectively. CCK-8 assays were performed on the extract of this material, and the relative cell viability was 90%, with a 24-hour antibacterial rate of 91%.

[0053] Example 3

[0054] ①The titanium alloy substrate was polished with sandpaper of 120, 320, 600 and 800 grit in sequence to remove the oxide film on the surface and obtain a smooth surface. Then it was ultrasonically cleaned in acetone, anhydrous ethanol and deionized water for 15 minutes in sequence.

[0055] ② The cleaned titanium alloy substrate was placed in an electrolytic cell for anodizing treatment. The electrode spacing was 20 cm, the voltage was 20 V, and the electrolyte consisted of deionized water, glycerol and ethylene glycol in a volume ratio of 2:1:1. The electrolyte solutes were 2 wt% sulfuric acid, 5 wt% hydrofluoric acid and 0.75 wt% sodium dodecyl sulfate. The electrolysis time was 4 h.

[0056] ③ Prepare vacuum-loaded solution media with bone-promoting / angiogenic / anti-infection functions: The bone-promoting solution media is a mixed solution of bone-promoting peptide / sodium alginate / glycerol / deionized water, wherein the bone-promoting peptide is BMP-2 with a concentration of 30 μg / ml; the sodium alginate concentration is 0.5 wt% with a viscosity > 0.002 Pas; and the glycerol concentration is 2 wt%. The angiogenic solution media is a mixed solution of angiogenic peptide / sodium alginate / glycerol / deionized water, wherein the angiogenic peptide is VEGF with a concentration of 30 μg / ml; the sodium alginate concentration is 0.5 wt% with a viscosity > 0.002 Pas; and the glycerol concentration is 2 wt%. The anti-infection solution media is a 5 wt% commercial povidone-iodine solution / povidone-iodine powder / sodium alginate / glycerol mixed solution, wherein the povidone-iodine powder concentration is 2 wt%; the sodium alginate concentration is 0.5 wt% with a viscosity > 0.002 Pas; and the glycerol concentration is 3 wt%.

[0057] ④ The anodized titanium alloy substrate material from step ② was sequentially placed in the above-mentioned bone-promoting vacuum loading solution medium, blood vessel-promoting vacuum loading solution medium, and anti-infection vacuum loading solution medium for cyclic vacuum loading. The vacuuming time was 30 min, the vacuum degree was 100 Pa, and the holding time was 20 min. Each step of vacuum loading in the anti-infection, blood vessel-promoting, and bone-promoting solution media was repeated 5 times to ensure sufficient loading. After each vacuum loading, the sample surface was rinsed three times with deionized water to remove residual vacuum loading solution medium. After vacuum loading in the anti-infection solution medium, the sample was dried at 35°C for 24 hours, and after vacuum loading in the blood vessel-promoting and bone-promoting solution media, the sample was dried at 35°C for 6 hours.

[0058] ⑤ Place the material from step ④ in Tris-HCl (pH=8.5) containing TA (4 mg / ml) and shake at 80 rpm for 24 h;

[0059] ⑥ After cleaning, packaging, and irradiation sterilization, the desired anti-infection / osteopromoting multifunctional orthopedic implant device based on vacuum sequential loading process is obtained.

[0060] ⑦ Compared with Example 1, the mass fraction of povidone-iodine powder was reduced, and the total release of povidone-iodine decreased to about 72% of that in Example 1; SEM analysis of the above material showed that the average diameter of titanium nanotubes was 117 nm. The extract of the material was subjected to CCK-8 test, and the relative cell activity was 91%, and the 24-hour antibacterial rate was 87%.

[0061] Example 4

[0062] ①The titanium alloy substrate was polished with sandpaper of 120, 320, 600 and 800 grit in sequence to remove the oxide film on the surface and obtain a smooth surface. Then it was ultrasonically cleaned in acetone, anhydrous ethanol and deionized water for 15 minutes in sequence.

[0063] ② The cleaned titanium alloy substrate was placed in an electrolytic cell for anodizing treatment. The electrode spacing was 20 cm, the voltage was 20 V, and the electrolyte consisted of deionized water, glycerol and ethylene glycol in a volume ratio of 2:1:1. The electrolyte solutes were 2 wt% sulfuric acid, 5 wt% hydrofluoric acid and 0.75 wt% sodium dodecyl sulfate. The electrolysis time was 4 h.

[0064] ③ Prepare vacuum-loaded solution media with bone-promoting / angiogenic / anti-infection functions: The bone-promoting solution media is a mixed solution of bone-promoting peptide / sodium alginate / glycerol / deionized water, wherein the bone-promoting peptide is BMP-2 with a concentration of 30 μg / ml; the sodium alginate concentration is 0.5 wt% with a viscosity > 0.002 Pas; and the glycerol concentration is 2 wt%. The angiogenic solution media is a mixed solution of angiogenic peptide / sodium alginate / glycerol / deionized water, wherein the angiogenic peptide is VEGF with a concentration of 30 μg / ml; the sodium alginate concentration is 0.5 wt% with a viscosity > 0.002 Pas; and the glycerol concentration is 2 wt%. The anti-infection solution media is a 5 wt% commercial povidone-iodine solution / povidone-iodine powder / sodium alginate / glycerol mixed solution, wherein the povidone-iodine powder concentration is 10 wt%; the sodium alginate concentration is 0.5 wt% with a viscosity > 0.002 Pas; and the glycerol concentration is 3 wt%.

[0065] ④ The anodized titanium alloy substrate material from step ② was sequentially placed in the above-mentioned bone-promoting vacuum loading solution medium, blood vessel-promoting vacuum loading solution medium, and anti-infection vacuum loading solution medium for cyclic vacuum loading. The vacuuming time was 30 min, the vacuum degree was 100 Pa, and the holding time was 20 min. Each step of vacuum loading in the anti-infection, blood vessel-promoting, and bone-promoting solution media was repeated 5 times to ensure sufficient loading. After each vacuum loading, the sample surface was rinsed three times with deionized water to remove residual vacuum loading solution medium. After vacuum loading in the anti-infection solution medium, the sample was dried at 35°C for 24 hours, and after vacuum loading in the blood vessel-promoting and bone-promoting solution media, the sample was dried at 35°C for 6 hours.

[0066] ⑤ Place the material from step ④ in Tris-HCl (pH=8.5) containing TA (16 mg / ml) and shake at 80 rpm for 48 h;

[0067] ⑥ After cleaning, packaging, and irradiation sterilization, the desired anti-infection / osteopromoting multifunctional orthopedic implant device based on vacuum sequential loading process is obtained.

[0068] ⑦ Compared with Example 1, the concentration of TA and the self-polymerization time were increased. Due to the extended polymerization time, the active components loaded during polymerization were lost, and the total release of each group decreased slightly. The total release of iodide ions was 91% of that in Example 1, the total release of angiogenic peptides was 87% of that in Example 1, and the total release of bone-promoting peptides was 89% of that in Example 1. Furthermore, the increased thickness of the PTA coating on the surface led to a decrease in the release rate of active components inside the nanotubes and a prolonged release time. The maximum release rate occurred at approximately 10 days, 24 days, and 60 days, respectively. SEM analysis of the above materials showed that the average diameter of the titanium nanotubes was approximately 122 nm. CCK-8 assay was performed on the extract of this material, and the relative cell viability was 95%, with a 24-hour antibacterial rate of 85%.

[0069] Example 5

[0070] ①The titanium alloy substrate was polished with sandpaper of 120, 320, 600 and 800 grit in sequence to remove the oxide film on the surface and obtain a smooth surface. Then it was ultrasonically cleaned in acetone, anhydrous ethanol and deionized water for 15 minutes in sequence.

[0071] ② The cleaned titanium alloy substrate was placed in an electrolytic cell for anodizing treatment. The electrode spacing was 20 cm, the voltage was 20 V, and the electrolyte consisted of deionized water, glycerol and ethylene glycol in a volume ratio of 2:1:1. The electrolyte solutes were 2 wt% sulfuric acid, 5 wt% hydrofluoric acid and 0.75 wt% sodium dodecyl sulfate. The electrolysis time was 4 h.

[0072] ③ Prepare vacuum-loaded solution media with bone-promoting / angiogenic / anti-infection functions: The bone-promoting solution media is a mixed solution of bone-promoting peptide / sodium alginate / glycerol / deionized water, wherein the bone-promoting peptide is BMP-2 with a concentration of 30 μg / ml; the sodium alginate concentration is 0.5 wt% with a viscosity > 0.002 Pas; and the glycerol concentration is 2 wt%. The angiogenic solution media is a mixed solution of angiogenic peptide / sodium alginate / glycerol / deionized water, wherein the angiogenic peptide is VEGF with a concentration of 30 μg / ml; the sodium alginate concentration is 0.5 wt% with a viscosity > 0.002 Pas; and the glycerol concentration is 2 wt%. The anti-infection solution media is a 5 wt% commercial povidone-iodine solution / povidone-iodine powder / sodium alginate / glycerol mixed solution, wherein the povidone-iodine powder concentration is 10 wt%; the sodium alginate concentration is 0.5 wt% with a viscosity > 0.002 Pas; and the glycerol concentration is 3 wt%.

[0073] ④ The anodized titanium alloy substrate material from step ② is sequentially placed in the above-mentioned bone-promoting vacuum loading solution medium, blood vessel-promoting vacuum loading solution medium, and anti-infection vacuum loading solution medium for cyclic vacuum loading. The vacuuming time is 30 min, the vacuum degree is 100 Pa, and the holding time is 20 min. The vacuum loading of the blood vessel-promoting and bone-promoting solution media is repeated 5 times each to ensure sufficient loading. The vacuum loading of the anti-infection solution medium is repeated 10 times to increase the iodine loading. After each vacuum loading, the sample surface is rinsed three times with deionized water to remove residual vacuum loading solution medium. After vacuum loading the anti-infection solution medium, it is dried at 35°C for 24 hours. After vacuum loading the blood vessel-promoting and bone-promoting solution media, it is dried at 35°C for 6 hours.

[0074] ⑤ Place the material from step ④ in Tris-HCl (pH=8.5) containing TA (4 mg / ml) and shake at 80 rpm for 24 h;

[0075] ⑥ After cleaning, packaging, and irradiation sterilization, the desired anti-infection / osteopromoting multifunctional orthopedic implant device based on vacuum sequential loading process is obtained.

[0076] ⑦ Compared with Example 1, the number of times the anti-infective drug was vacuum loaded was increased, and the total amount of iodine ions released increased to about 132% of that in Example 1; the iodine release time was relatively prolonged, with the maximum release rate occurring around 8 days; SEM analysis of the above material showed that the average diameter of the titanium nanotubes was 118 nm. When the extract of this material was subjected to CCK-8 assay, the relative cell activity was 82%, and the 24-hour antibacterial rate was >99%.

[0077] Example 6

[0078] ①The titanium alloy substrate was polished with sandpaper of 120, 320, 600 and 800 grit in sequence to remove the oxide film on the surface and obtain a smooth surface. Then it was ultrasonically cleaned in acetone, anhydrous ethanol and deionized water for 15 minutes in sequence.

[0079] ② The cleaned titanium alloy substrate was placed in an electrolytic cell for anodizing treatment. The electrode spacing was 20 cm, the voltage was 20 V, and the electrolyte consisted of deionized water, glycerol and ethylene glycol in a volume ratio of 2:1:1. The electrolyte solutes were 2 wt% sulfuric acid, 5 wt% hydrofluoric acid and 0.75 wt% sodium dodecyl sulfate. The electrolysis time was 4 h.

[0080] ③ Prepare vacuum-loaded solution media with bone-promoting / angiogenic / anti-infection functions: The bone-promoting solution media is a mixed solution of bone-promoting peptide / sodium alginate / glycerol / deionized water, wherein the bone-promoting peptide is BMP-2 with a concentration of 30 μg / ml; the sodium alginate concentration is 0.5 wt% with a viscosity > 0.002 Pas; and the glycerol concentration is 2 wt%. The angiogenic solution media is a mixed solution of angiogenic peptide / sodium alginate / glycerol / deionized water, wherein the angiogenic peptide is VEGF with a concentration of 30 μg / ml; the sodium alginate concentration is 0.5 wt% with a viscosity > 0.002 Pas; and the glycerol concentration is 2 wt%. The anti-infection solution media is a 5 wt% commercial povidone-iodine solution / povidone-iodine powder / sodium alginate / glycerol mixed solution, wherein the povidone-iodine powder concentration is 10 wt%; the sodium alginate concentration is 0.5 wt% with a viscosity > 0.002 Pas; and the glycerol concentration is 3 wt%.

[0081] ④ The anodized titanium alloy substrate material from step ② is sequentially placed in the above-mentioned bone-promoting vacuum loading solution medium, blood vessel-promoting vacuum loading solution medium, and anti-infection vacuum loading solution medium for cyclic vacuum loading. The vacuuming time is 30 min, the vacuum degree is 100 Pa, and the holding time is 20 min. The vacuum loading of the anti-infection solution medium is repeated 5 times, and the vacuum loading of the blood vessel-promoting and bone-promoting solution mediums is repeated 10 times to increase the loading amount of blood vessel-promoting and bone-promoting drugs. After each vacuum loading, the sample surface is rinsed three times with deionized water to remove residual vacuum loading solution medium. After vacuum loading the anti-infection solution medium, it is dried at 35°C for 24 hours, and after vacuum loading the blood vessel-promoting and bone-promoting solution mediums, it is dried at 35°C for 6 hours.

[0082] ⑤ Place the material from step ④ in Tris-HCl (pH=8.5) containing TA (4 mg / ml) and shake at 80 rpm for 24 h;

[0083] ⑥ After cleaning, packaging, and irradiation sterilization, the desired anti-infection / osteopromoting multifunctional orthopedic implant device based on vacuum sequential loading process is obtained.

[0084] ⑦ Compared with Example 1, the number of repetitions of vacuum-loaded angiogenesis-promoting and osteogenic peptides was increased. The total release of iodine was approximately 68% of that in Example 1, the total release of angiogenesis-promoting peptides was 140% of that in Example 1, and the total release of osteogenic peptides was 129% of that in Example 1. The SEM analysis of the above materials showed that the average diameter of the titanium nanotubes was 114 nm. The CCK-8 assay of the extract of the material showed a relative cell activity of 92% and a 24-hour antibacterial rate of 83%.

[0085] The embodiments described above provide a detailed explanation of the technical solutions and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, additions, and equivalent substitutions made within the scope of the principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a programmable drug-release, multifunctional orthopedic implant for anti-infection and osteopromoting purposes, characterized in that, Includes the following steps: (1) Remove the oxide film on the surface of the titanium alloy substrate, clean it with ultrasonication, and then perform anodizing treatment on the cleaned titanium alloy substrate to obtain a titanium alloy substrate material containing titanium nanotubes (TNT). Prepare bone-promoting vacuum loading solutions, blood vessel-promoting vacuum loading solutions, and anti-infective vacuum loading solutions; (2) The titanium alloy substrate material containing titanium nanotubes (TNT) was sequentially placed in a bone-promoting vacuum loading solution, a blood vessel-promoting vacuum loading solution, and an anti-infection vacuum loading solution for vacuum sequential loading, resulting in a multifunctional material containing bone-promoting components, blood vessel-promoting components, and anti-infection components in the TNT tubes from bottom to top. (3) The multifunctional material is placed in Tris-HCl containing tannic acid (TA) and shaken for 12-72 hours to achieve in-situ self-polymerization of TA and form a polytannic acid (PTA) coating on the surface of the multifunctional material. After cleaning, encapsulation and irradiation sterilization, an anti-infection and osteopromoting multifunctional orthopedic implant based on vacuum sequential loading process is obtained. In step (1), the anodizing process includes: placing the cleaned titanium alloy substrate in an electrolytic cell for anodizing, wherein the anode in the electrolytic cell is a titanium alloy sample, the cathode is a titanium plate, the electrode spacing is 15-25 cm, the voltage is 15-25 V, the electrolyte solvent is composed of deionized water, glycerol and ethylene glycol in a volume ratio of 2:1:1, the electrolyte solute is 1-2 wt% sulfuric acid, 1-5 wt% hydrofluoric acid and 0.25-0.75 wt% sodium dodecyl sulfate; the electrolysis time is 1-4 h. The anti-infective vacuum-loaded solution is a mixture of 5wt% commercial povidone-iodine solution, povidone-iodine powder, sodium alginate, and glycerol. The concentration of povidone-iodine powder is 1-10wt%; the concentration of sodium alginate is 0.25-0.75wt% with a viscosity >0.002 Pas; the concentration of glycerol is 0.5-5wt%; and the remainder is 5wt% commercial povidone-iodine solution.

2. The method for preparing the programmable drug-release, anti-infective, and osteopromoting multifunctional orthopedic implant according to claim 1, characterized in that, In step (1), the method for removing the oxide film on the surface of the titanium alloy substrate is as follows: the titanium alloy substrate is polished in sequence with sandpaper or grinding wheel with a mesh size of 120, 320, 600 and 800 to remove the oxide film on the surface and obtain a smooth surface; the ultrasonic cleaning is performed by placing the substrate in acetone, anhydrous ethanol and deionized water in sequence for ultrasonic cleaning, with a cleaning power of 80-100w and a cleaning time of 15-30min.

3. The method for preparing the programmable drug-release, anti-infective, and osteopromoting multifunctional orthopedic implant according to claim 1, characterized in that, Each anodizing process requires the electrolyte to completely submerge the titanium alloy substrate, and the electrolyte needs to be replaced when the current is less than 0.02A.

4. The method for preparing the programmable drug-release, anti-infective, and osteopromoting multifunctional orthopedic implant according to claim 1, characterized in that, In step (1), the pore size of the titanium nanotubes (TNT) is 80-120 nm.

5. The method for preparing the programmable drug-release, anti-infective, and osteopromoting multifunctional orthopedic implant according to claim 1, characterized in that, The bone-promoting vacuum-loaded solution is a mixed solution of bone-promoting polypeptide, sodium alginate, glycerol, and deionized water. The bone-promoting polypeptide is one or more of BMP-2, bone growth peptide OGP, BMP-7, and TGF-β, with a concentration of 10-50 μg / ml; the sodium alginate concentration is 0.25-0.75 wt%, and the viscosity is >0.002 Pas; the glycerol concentration is 0.25-2.5 wt%, and the remainder is deionized water. The aforementioned angiogenic vacuum loading solution is a mixed solution of angiogenic peptides, sodium alginate, glycerol, and deionized water. The angiogenic peptides are one or more of α-FGF, β-FGF, PD-ECGF, TGF, TNF, and VEGF, with a concentration of 5-50 μg / ml. The sodium alginate concentration is 0.25-0.75 wt%, and the viscosity is >0.002 Pas. The glycerol concentration is 0.25-2.5 wt%, and the remainder is deionized water.

6. The method for preparing the programmable drug-release, anti-infective, and osteopromoting multifunctional orthopedic implant according to claim 1, characterized in that, In step (2), the specific steps of vacuum sequential loading include: 1) The titanium alloy substrate material containing titanium nanotubes (TNT) was placed in a bone-promoting vacuum loading solution for vacuum loading. The resulting product was washed with deionized water and dried in a forced-air drying process at 25-35°C for 24-72 hours to obtain a material containing bone-promoting components. 2) Place the material containing bone-promoting components obtained in step 1) into a vascular-promoting vacuum loading solution for vacuum loading. Wash the resulting product with deionized water and dry it in a forced-air drying environment at 25-35°C for 6-24 hours to obtain a material containing both bone-promoting and vascular-promoting components. 3) The material containing bone-promoting and angiogenesis-promoting components obtained in step 2) is placed in an anti-infective vacuum loading solution for vacuum loading. The resulting product is rinsed with deionized water and dried in a forced-air drying environment at 25-35°C for 6-24 hours to obtain a multifunctional material containing bone-promoting, angiogenesis-promoting, and anti-infective components sequentially from bottom to top inside the TNT tube.

7. The method for preparing a multifunctional orthopedic implantable device with programmable drug release for anti-infection and osteopromoting effects according to claim 6, characterized in that, The vacuum load has a vacuuming time of 5-30 min, a vacuum degree of 1-100 Pa, and a pressure holding time of 2-20 min.

8. The method for preparing the multifunctional orthopedic implantable device with programmable drug release for anti-infection and osteopromoting effects according to claim 1, characterized in that, In step (3), the pH of the Tris-HCl containing tannic acid (TA) is 8.5, and the TA content is 2-16 mg / ml; the shaking rate is 40-120 rpm, and the reaction temperature is 25-37℃.

9. A programmable drug-release, multifunctional orthopedic implant for both anti-infection and osteopromoting purposes, characterized in that, Prepared using the method described in any one of claims 1-8.

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