Preparation method of titanium and titanium alloy surface nanotube slow-release structure coating

Abstract

The application discloses a preparation method of a titanium and titanium alloy surface nanotube slow-release structure coating, and specifically comprises the following steps: firstly, a titanium and titanium alloy surface special structure nanotube coating is prepared; then, the titanium and titanium alloy surface special structure nanotube coating is soaked in a precursor solution, ultrasonic treatment is carried out, vacuum drying is carried out, the obtained functional nanoparticles or drug-loaded titanium and titanium alloy surface nanotube structure coating is placed into a hydrothermal reaction solution to carry out reaction, the obtained titanium and titanium alloy surface nanotube slow-release structure coating is placed in a medium to carry out polarization, and the titanium and titanium alloy surface nanotube slow-release structure coating can be obtained. The titanium and titanium alloy surface nanotube slow-release structure coating prepared by the application has a piezoelectric effect, can promote osteoblast proliferation and differentiation, can load various drugs and ions, and has a long slow-release period.

Description

Technical Field

[0001] This invention belongs to the field of titanium and titanium alloy coating preparation technology, specifically relating to a method for preparing nanotube slow-release structure coatings on the surface of titanium and titanium alloys. Background Technology

[0002] Titanium and titanium alloys possess excellent mechanical properties, low density, high specific strength, and good biocompatibility, making them widely used in various biomedical treatments and consumer products. However, clinical studies have shown that titanium and its alloys are bioinert materials and, after implantation, cannot form good osseointegration with human bone, posing a risk of implantation failure. Since the various properties of titanium-based implants play a crucial role in osseointegration, surface modification of titanium implants is an important measure to enhance the integration between the implant and bone and improve the success rate of implantation surgery. This can increase the success rate of titanium alloy implants, enabling their better application in the medical field.

[0003] However, as foreign objects in the human body, titanium implants often carry the risk of bacterial infection during implantation or service, which is a significant cause of implant failure. Once infection occurs, bacteria multiply on the surface of the titanium implant, eventually forming a biofilm that affects the interfacial bonding between the implant and human bone tissue, ultimately leading to implant failure. Furthermore, treating bacterial infections is complex and difficult, and can cause more serious problems for patients. While antibiotics can effectively kill bacteria, excessive use can lead to antibiotic resistance and the formation of resistant strains. Therefore, endowing titanium and titanium alloys with antibacterial properties or other functional ion-releasing capabilities through surface modification techniques is of great significance for the practical application of titanium implants.

[0004] In recent years, improving the biocompatibility, wear resistance, corrosion resistance, and antibacterial properties of titanium-based implants through various surface modification techniques has become a research hotspot in the field of medical titanium alloys. Among drug-loaded coating systems on titanium and titanium alloy surfaces, titanium dioxide nanotube structures have attracted widespread attention. Studies have shown that TiO2 nanotube coatings on titanium alloy surfaces promote osteoblast proliferation and inhibit bacterial biofilm formation, while the nanotube structure also exhibits good drug-loading properties. However, after loading drugs into titanium dioxide nanotubes on titanium surfaces, 70% of the drug in the nanotubes is released into surrounding tissues within approximately 5 hours of the start of drug release, resulting in excessively high local drug concentrations and toxic reactions. The local drug concentration, after a brief increase, rapidly drops below the minimum antibacterial concentration. Traditional nanotube structures struggle to achieve controlled and slow release of drugs or functional ions from nanotubes. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing nanotube sustained-release structure coatings on the surface of titanium and titanium alloys, thereby solving the problem of explosive drug release in the initial stage of drug release in nanotube structure coatings prepared by existing technologies.

[0006] The technical solution adopted in this invention is a method for preparing a nanotube slow-release structure coating on the surface of titanium and titanium alloys, which is implemented according to the following steps:

[0007] Step 1: Preparation of special structured nanotube coatings on the surface of titanium and titanium alloys;

[0008] Step 2: Dissolve the drug precursor or functional ionic precursor in a solvent to form a solution, then immerse the special structured nanotube coating on the surface of titanium and titanium alloy in the solution, and perform ultrasonic treatment and vacuum drying to obtain a functional nanoparticle or drug-loaded nanotube structure coating on the surface of titanium and titanium alloy.

[0009] Step 3: Place the functional nanoparticles or drug-loaded titanium and titanium alloy surface nanotube structure coating into a hydrothermal reaction solution for reaction to obtain the titanium and titanium alloy surface nanotube sustained-release structure coating.

[0010] Step 4: Place the nanotube slow-release structure coating on the surface of titanium and titanium alloy obtained in Step 3 in a medium and polarize it to obtain the nanotube slow-release structure coating on the surface of titanium and titanium alloy.

[0011] The invention is further characterized in that,

[0012] Step 1 specifically involves:

[0013] Ethylene glycol, water, and ammonium fluoride are mixed evenly to form a primary anodizing solution. After oxidation at 40–120V for 40–100 min, the sample after removing the surface oxide layer is placed in a secondary anodizing solution and oxidized at 40–80V for 20–60 min. The sample is then removed and cleaned. A tertiary anodizing solution is then added, and the sample is oxidized at 10–60V for 30–80 min. Finally, the titanium and titanium alloy surface coating is heat-treated at 450℃ for 4 h to obtain a special structured nanotube coating.

[0014] The volume ratio of ethylene glycol, water, and ammonium fluoride in the primary anodizing solution is 200:5:1; the molar ratio of ethylene glycol, water, and ammonium fluoride in the secondary anodizing solution is 200:5:1; and the volume ratio of glycerol, water, and ammonium fluoride in the tertiary anodizing solution is 75:50:1.

[0015] In step 2, the drug is vancomycin hydrochloride or alendronate sodium; the functional nano-ions are any one of potassium ions, calcium ions, zinc ions, selenium ions, and silver ions; the solvent is deionized water or anhydrous ethanol; and the ultrasonic treatment time is 5 to 20 minutes.

[0016] In step 3, the hydrothermal reaction solution is any one or both of barium hydroxide solution and strontium hydroxide solution; the concentration of both barium hydroxide solution and strontium hydroxide solution is 0.02 mol / L to 0.10 mol / L.

[0017] In step 3, the reaction temperature is 180–240℃ and the reaction time is 1–3 hours.

[0018] In step 4, the medium is air or silicone oil; during polarization, the polarization field strength is 1-4 kV / mm, the polarization temperature is 80-150℃, and the polarization time is 20-120 min.

[0019] The beneficial effects of this invention are that the nanotube sustained-release structure coating on the surface of titanium and titanium alloys and the preparation method thereof solve the problem of explosive release in the early stage of drug release of nanotube structure coatings prepared by the prior art. The prepared nanotube sustained-release structure coating on the surface of titanium and titanium alloys has a piezoelectric effect, which can promote osteoblast proliferation and differentiation, can load a variety of drugs and ions, and has a long sustained-release period. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the nanotube slow-release structure coating on the surface of titanium and titanium alloys. Detailed Implementation

[0021] The present invention will now be described in detail with reference to specific embodiments and accompanying drawings.

[0022] The present invention discloses a method for preparing a nanotube sustained-release structure coating on the surface of titanium and titanium alloys. The method involves preparing a nanotube array with a special structure on the surface of titanium and titanium alloys by a three-stage anodizing process. After heat treatment, drugs or functional ions are loaded, and then a hydrothermal reaction is carried out to prepare a nanotube sustained-release structure coating on the surface of titanium and titanium alloys.

[0023] The specific steps are as follows:

[0024] Step 1: Preparation of special structured nanotube coatings on the surface of titanium and titanium alloys;

[0025] Specifically, ethylene glycol, water, and ammonium fluoride are mixed evenly to form a primary anodizing solution. After oxidizing at 40–120V for 40–100 min, the surface oxide layer is removed, and a secondary anodizing solution is added. After oxidizing at 40–80V for 20–60 min, the solution is removed and cleaned. Then, a tertiary anodizing solution is added, and the solution is oxidized at 10–60V for 30–80 min. Finally, the titanium and titanium alloy surface coating is heat-treated at 450℃ for 4 h to obtain a special structured nanotube coating.

[0026] The volume ratio of ethylene glycol, water, and ammonium fluoride in the primary anodizing solution is 200:5:1;

[0027] The molar ratio of ethylene glycol, water, and ammonium fluoride in the secondary anodizing solution is 200:5:1;

[0028] In the three-stage anodizing solution, the volume ratio of glycerol, water, and ammonium fluoride is 75:50:1.

[0029] Step 2, loading of functional nano-ions or drugs;

[0030] Specifically, the process involves dissolving a drug precursor or a functional ionic precursor in a solvent to form a solution, then immersing a special structured nanotube coating on the surface of titanium and titanium alloys in the solution and subjecting it to ultrasonic treatment. Finally, the solution is placed in a vacuum drying oven for drying, thereby obtaining a nanotube structured coating on the surface of titanium and titanium alloys loaded with functional nanoparticles or drugs.

[0031] The medication is either vancomycin hydrochloride or alendronate sodium.

[0032] The functional nano-ions are any one of potassium ions, calcium ions, zinc ions, selenium ions, and silver ions;

[0033] The solvent is deionized water or anhydrous ethanol; the ultrasonic treatment time is 5–20 min.

[0034] Step 3, Preparation of nanotube slow-release structure coating on titanium and titanium alloy surfaces;

[0035] The nanotube structure coating on the surface of titanium and titanium alloys prepared in step 2, which contains functional nanoparticles or drug-loaded materials, is placed in a hydrothermal reaction solution for reaction to obtain a sustained-release nanotube structure coating on the surface of titanium and titanium alloys.

[0036] The hydrothermal reaction solution is any one or both of barium hydroxide solution and strontium hydroxide solution;

[0037] The concentrations of both barium hydroxide solution and strontium hydroxide solution are 0.02 mol / L to 0.10 mol / L;

[0038] The volume ratio of barium hydroxide solution to strontium hydroxide solution is 1-2:0-1;

[0039] The reaction temperature is 180–240℃, and the reaction time is 1–3 hours.

[0040] Step 4: Place the nanotube slow-release structure coating on the surface of titanium and titanium alloy obtained in Step 3 in a medium and polarize it for 20 to 120 minutes at a polarization field strength of 1 to 4 kV / mm and a polarization temperature of 80 to 150 °C to obtain the nanotube slow-release structure coating on the surface of titanium and titanium alloy.

[0041] The medium is air or silicone oil;

[0042] The present invention discloses a method for preparing a nanotube sustained-release structure coating on titanium and titanium alloy surfaces. This method utilizes a three-stage anodic oxidation combined with a hydrothermal reaction to obtain a nanotube sustained-release structure coating with a piezoelectric effect. This solves the problems of low drug loading and explosive release in existing nanotube structure coatings. Furthermore, the piezoelectric effect of this coating can promote osteoblast proliferation and differentiation. This method is of significant value for obtaining titanium and titanium alloy surface coatings with controllable release of healthy ions and drugs.

[0043] Example 1

[0044] The method for preparing the nanotube sustained-release structure coating on the surface of titanium and titanium alloys of the present invention is as follows:

[0045] Ethylene glycol, water, and ammonium fluoride were mixed evenly in a volume ratio of 200:5:1 to form a primary anodizing solution. After oxidizing the sample at 40V for 100 min, the surface oxide layer was removed, and a secondary anodizing was performed. The secondary anodizing solution was prepared by mixing ethylene glycol, water, and ammonium fluoride in a molar ratio of 200:5:1. After oxidizing at 40V for 60 min, the sample was removed and cleaned. Then, a tertiary anodizing solution was added. The tertiary anodizing solution was prepared by mixing glycerol, water, and ammonium fluoride in a volume ratio of 75:50:1. The oxidation time was 30 min, and the oxidation voltage was 60V. After the titanium and titanium alloy surface coatings were anodized three times, a special structured nanotube coating was obtained by heat treatment at 450℃ for 4 h.

[0046] Vancomycin hydrochloride was dissolved in deionized water, and the prepared coating sample was then immersed in the solution and sonicated for 5 minutes before being dried in a vacuum drying oven. The dried sample was then subjected to a hydrothermal reaction in a 0.03 mol / L barium hydroxide aqueous solution at 200°C for 2 hours. The hydrothermally treated sample was then placed in air and polarized at a polarization field of 1.5 kV / mm and a polarization temperature of 150°C for 30 minutes to obtain a barium titanate nanotube slow-release structure coating on the surface of titanium and titanium alloys.

[0047] Example 2

[0048] The method for preparing the nanotube sustained-release structure coating on the surface of titanium and titanium alloys of the present invention is as follows:

[0049] Ethylene glycol, water, and ammonium fluoride were mixed evenly in a volume ratio of 200:5:1 to form a primary anodizing solution. The sample was oxidized at 120V for 40 minutes, and after removing the surface oxide layer, a secondary anodizing solution was performed. The secondary anodizing solution was prepared by mixing ethylene glycol, water, and ammonium fluoride in a molar ratio of 200:5:1. After oxidizing at 80V for 20 minutes, the sample was removed and cleaned. Then, a tertiary anodizing solution was added. The tertiary anodizing solution was prepared by mixing glycerol, water, and ammonium fluoride in a volume ratio of 75:50:1. The oxidation time was 80 minutes and the oxidation voltage was 10V. After the titanium and titanium alloy surface coatings were anodized three times, a special structured nanotube coating was obtained by heat treatment at 450℃ for 4 hours.

[0050] Sodium alendronate was dissolved in deionized water, and the prepared coating sample was then immersed in the solution and sonicated for 20 minutes before being dried in a vacuum drying oven. The dried sample was then subjected to a hydrothermal reaction in a 0.1 mol / L mixed aqueous solution of barium hydroxide and strontium hydroxide at 180°C for 1 hour. The hydrothermally treated sample was then placed in air and polarized at a polarization field of 1 kV / mm and a polarization temperature of 80°C for 120 minutes to obtain a sustained-release strontium barium titanate nanotube coating on the surface of titanium and titanium alloys.

[0051] Example 3

[0052] The method for preparing the nanotube sustained-release structure coating on the surface of titanium and titanium alloys of the present invention is as follows:

[0053] Ethylene glycol, water, and ammonium fluoride were mixed evenly in a volume ratio of 200:5:1 to form a primary anodizing solution. After oxidizing the sample at 60V for 60 minutes, the surface oxide layer was removed, followed by a secondary anodizing. The secondary anodizing solution was prepared by mixing ethylene glycol, water, and ammonium fluoride in a molar ratio of 200:5:1. After oxidizing at 60V for 30 minutes, the sample was removed and cleaned. Then, a tertiary anodizing solution was added. The tertiary anodizing solution was prepared by mixing glycerol, water, and ammonium fluoride in a volume ratio of 75:50:1. The oxidation time was 45 minutes, and the oxidation voltage was 30V. After the titanium and titanium alloy surface coatings were anodized three times, they were heat-treated at 450℃ for 4 hours to obtain a special structured nanotube coating.

[0054] Silver nitrate solution was dissolved in deionized water, and the prepared coating sample was then immersed in the solution and sonicated for 10 minutes before being dried in a vacuum drying oven. The dried sample underwent post-treatment (UV irradiation). The treated sample was then subjected to a hydrothermal reaction in a 0.02 mol / L mixed aqueous solution of barium hydroxide and strontium hydroxide at 240℃ for 3 hours. The hydrothermally treated sample was then placed in silicone oil and polarized at a polarization field of 4 kV / mm and a polarization temperature of 120℃ for 20 minutes to obtain a barium strontium titanate nanotube slow-release structure coating on the surface of titanium and titanium alloys.

[0055] The introduction of nanotube sustained-release structures helps improve the sustained release of functional ions or drugs from titanium and titanium alloy surface coatings, extending their action period. By designing nanotube structures, both controlled release of functional ions or drugs and the loading of larger quantities of drugs or functional ions can be achieved. In particular, when the loading of drugs or functional ions lies between anodic oxidation and hydrothermal reactions, the newly formed piezoelectric phase can physically blend with the drug, or form doping or blending with the functional ions, further delaying the release process. Simultaneously, by introducing the piezoelectric effect, the attraction between positive and negative charges can control the release of drugs or functional ions to some extent. Furthermore, the presence of the piezoelectric effect is also beneficial to cell growth and reproduction.

[0056] Figure 1 This is a schematic diagram of the nanotube slow-release structure coating on the surface of titanium and titanium alloys. As can be seen from the figure, the nanotube slow-release structure coating on the titanium surface is composed of nanotubes with a special structure. From the inside out, a single nanotube consists of an inner layer composed of functional ions and a piezoelectric phase, and an outer layer composed of titanium dioxide.

[0057] Table 1 shows a comparison of the drug release characteristics, nanotube structure, release period, and piezoelectric coefficient between Examples 1, 2, and 3 of this invention and typical titanium dioxide nanotube coatings on titanium surfaces. As can be seen from the table, unlike typical titanium dioxide nanotube coatings, Examples 1, 2, and 3 do not exhibit significant burst release behavior. Structurally, they also differ from typical nanotube structures, exhibiting a unique nanotube structure with a narrow top and branched bottom. Furthermore, the drug or functional ion release period of the examples is significantly longer than that of the titanium dioxide nanotubes in the control group. In addition, different piezoelectric coefficients were detected in all examples, indicating that the prepared titanium alloy surface coating possesses a piezoelectric effect, which is expected to promote osteoblast proliferation and differentiation.

[0058] Table 1. Performance comparison of Examples 1-3 and typical titanium dioxide nanotubes

[0059]

[0060]

Claims

1. A method for preparing a nanotube sustained-release structure coating on the surface of titanium and titanium alloys, characterized in that, The specific steps are as follows: Step 1, Preparation of a special structured nanotube coating on the surface of titanium and titanium alloys; specifically: Ethylene glycol, water, and ammonium fluoride are mixed evenly to form a primary anodizing solution. After oxidation at 40-120V for 40-100 minutes, the sample after removing the surface oxide layer is placed in a secondary anodizing solution and oxidized at 40-80V for 20-60 minutes. The sample is then removed and cleaned. A tertiary anodizing solution is then added, and the sample is oxidized at 10-60V for 30-80 minutes. Finally, the titanium and titanium alloy surface coating is heat-treated at 450℃ for 4 hours to obtain a special structured nanotube coating. The volume ratio of ethylene glycol, water, and ammonium fluoride in the primary anodizing solution is 200:5:1; the molar ratio of ethylene glycol, water, and ammonium fluoride in the secondary anodizing solution is 200:5:1; and the volume ratio of glycerol, water, and ammonium fluoride in the tertiary anodizing solution is 75:50:

1. Step 2: Dissolve the drug precursor or functional ionic precursor in a solvent to form a solution, then immerse the special structured nanotube coating on the surface of titanium and titanium alloy in the solution, and perform ultrasonic treatment and vacuum drying to obtain a functional nanoparticle or drug-loaded nanotube structure coating on the surface of titanium and titanium alloy. In step 2, the drug is vancomycin hydrochloride or alendronate sodium; the functional nano-ions are any one of potassium ions, calcium ions, zinc ions, selenium ions, and silver ions; the solvent is deionized water or anhydrous ethanol; and the ultrasonic treatment time is 5-20 minutes. Step 3: Place the functional nanoparticles or drug-loaded titanium and titanium alloy surface nanotube structure coating into a hydrothermal reaction solution for reaction to obtain the titanium and titanium alloy surface nanotube sustained-release structure coating. Step 4: Place the nanotube slow-release structure coating on the surface of titanium and titanium alloy obtained in Step 3 in a medium and polarize it to obtain the nanotube slow-release structure coating on the surface of titanium and titanium alloy. The nanotube slow-release structure coating on the titanium surface is composed of nanotubes with a special structure, exhibiting a unique nanotube structure with a narrow top and a branched bottom. From the inside out, each nanotube consists of an inner layer composed of functional ions and a piezoelectric phase, and an outer layer composed of titanium dioxide.

2. The method for preparing a nanotube slow-release structure coating on the surface of titanium and titanium alloys according to claim 1, characterized in that, In step 3, the hydrothermal reaction solution is any one or both of barium hydroxide solution and strontium hydroxide solution; the concentration of both barium hydroxide solution and strontium hydroxide solution is 0.02 mol / L to 0.10 mol / L.

3. The method for preparing a nanotube slow-release structure coating on the surface of titanium and titanium alloys according to claim 1, characterized in that, In step 3, the reaction temperature is 180~240℃ and the reaction time is 1~3h.

4. The method for preparing a nanotube slow-release structure coating on the surface of titanium and titanium alloys according to claim 1, characterized in that, In step 4, the medium is air or silicone oil; during polarization, the polarization field strength is 1~4kV / mm, the polarization temperature is 80~150℃, and the polarization time is 20~120min.

Images