Titanium alloy urethral stent with zinc-zirconium doped coating

Abstract

The invention provides a titanium alloy urethral stent with a zinc-zirconium doped coating, which is used for solving the problems that the corrosion resistance and biocompatibility of antibacterial coatings such as a silver coating and a copper coating prepared on the surface of a titanium alloy urethral stent are improved by adopting a micro-arc oxidation technology in the prior art; however, the antibacterial performance and the durability still cannot meet clinical requirements. According to the titanium alloy urethral stent with the zinc-zirconium-doped coating, the micro-arc oxidation technology is adopted to grow on the surface of the titanium alloy urethral stent body to form the porous structure and the zinc-zirconium-doped coating, zirconium and zinc in the coating play a synergistic effect, and on the premise that the stability and the biocompatibility of the coating are not affected, the titanium alloy urethral stent with the zinc-zirconium-doped coating can be used for preparing the titanium alloy urethral stent with the zinc-zirconium-doped coating. Compared with the prior art, the titanium alloy urethral stent has the advantages that the titanium alloy urethral stent not only can provide a better antibacterial effect and remarkably inhibit the growth of drug-resistant bacteria, but also can provide an obvious sterilizing effect, so that adverse reactions generated when the titanium alloy urethral stent is in contact with human tissues are greatly reduced, and the safety and reliability in long-term use are ensured; and the antibacterial effect is lasting and is not easy to attenuate.

Description

Technical Field

[0001] This invention relates to urethral stents, and more particularly to a titanium alloy urethral stent with a zinc-zirconium doped coating. Background Technology

[0002] Titanium alloys, a commonly used material in the biomedical field, possess excellent mechanical properties and biocompatibility, and have been widely applied in various implants, such as titanium alloy urethral stents in urology. However, after contact with human tissue, titanium alloy urethral stents are susceptible to bacterial invasion, especially drug-resistant bacteria, which can easily lead to implant failure. To improve the antibacterial properties of titanium alloy urethral stents, researchers have explored various surface modification techniques. Among them, micro-arc oxidation technology has become a widely studied surface modification technique in recent years because it can form a porous coating on the surface of titanium alloy urethral stents.

[0003] Currently, surface modification using micro-arc oxidation technology mainly involves preparing various antibacterial coatings on material surfaces, such as silver and copper coatings. However, most of these coatings suffer from problems such as excessively rapid release of metal ions, leading to a decline in antibacterial efficacy after long-term use. Furthermore, the biocompatibility and long-term stability of coatings on titanium alloy urethral stents are also challenges in current research. While antibacterial coatings such as silver and copper coatings prepared on the surface of titanium alloy urethral stents using micro-arc oxidation technology have improved corrosion resistance and biocompatibility, their antibacterial performance and durability still fail to meet clinical needs. Summary of the Invention

[0004] The purpose of this invention is to solve the technical problem that although the corrosion resistance and biocompatibility of antibacterial coatings such as silver coatings and copper coatings prepared on the surface of titanium alloy urethral stents using micro-arc oxidation technology have been improved, the antibacterial performance and durability still fail to meet clinical needs. The invention provides a titanium alloy urethral stent with a zinc-zirconium doped coating.

[0005] To achieve the above objectives, the technical solution provided by the present invention is as follows: A titanium alloy urethral stent with a zinc-zirconium doped coating includes a titanium alloy urethral stent body and a coating located on the surface of the titanium alloy urethral stent body; its distinctive feature lies in that it is prepared using the following steps: Step 1: Add zirconium salt and zinc salt to the electrolyte, wherein the amount of zirconium salt added is 10~30 g / L and the amount of zinc salt added is 10~20 g / L; Step 2: The titanium alloy urethral stent body is placed in an electrolyte containing zirconium salt and zinc salt. Micro-arc oxidation technology is used to continuously generate micro-arc discharge on the surface of the titanium alloy urethral stent body, thereby growing and forming the coating on the surface of the titanium alloy urethral stent body. The coating is a porous structure and has zinc and zirconium doping.

[0006] Furthermore, the thickness of the porous structure and the zinc- and zirconium-doped coating is 7~15 μm.

[0007] Furthermore, the thickness of the porous structure and the zinc- and zirconium-doped coating is 8.5~12 μm.

[0008] Furthermore, the thickness of the porous structure and the zinc- and zirconium-doped coating is 10.5 μm.

[0009] Furthermore, the zirconium salt is Na2ZrO3, and its addition amount is 14~16 g / L; The zinc salt is Na2ZnO2, and its addition amount is 10~12g / L.

[0010] Furthermore, the zirconium salt is Na2ZrO3, and its addition amount is 15 g / L; The zinc salt is Na2ZnO2, and its addition amount is 10g / L.

[0011] Furthermore, step 2 specifically involves: A titanium alloy urethral stent is placed in an electrolyte containing zirconium and zinc salts. Micro-arc oxidation technology is used to continuously apply the stent under a high-voltage pulsed electric field for 10-15 minutes, causing continuous micro-arc discharge on the surface of the titanium alloy urethral stent. This allows metal ions, oxygen ions, zirconium ions, zinc ions in the electrolyte, and titanium ions in the titanium alloy urethral stent to grow together and form a porous structure with a zinc and zirconium doped coating.

[0012] Furthermore, the electrolyte is a phosphate-based electrolyte.

[0013] Furthermore, the electrolyte is a sodium dihydrogen phosphate-based electrolyte, and the amount of sodium dihydrogen phosphate added is 10~30g / L; Alternatively, the electrolyte is a sodium hexametaphosphate-based electrolyte, with the amount of sodium hexametaphosphate added being 10~30 g / L.

[0014] Furthermore, the electrolyte is a sodium dihydrogen phosphate-based electrolyte, and the amount of sodium dihydrogen phosphate added is 20 g / L; Alternatively, the electrolyte is a sodium hexametaphosphate-based electrolyte, with the amount of sodium hexametaphosphate added being 20 g / L.

[0015] The advantages of this invention compared to the prior art are as follows: 1. The present invention provides a titanium alloy urethral stent with a zinc-zirconium doped coating. The stent employs micro-arc oxidation technology to grow a porous structure with a zinc- and zirconium doped coating on the surface of the titanium alloy urethral stent body. The zirconium and zinc in the coating work synergistically, providing not only good antibacterial effect and significantly inhibiting the growth of drug-resistant bacteria without affecting the stability and biocompatibility of the coating, but also providing significant bactericidal effect. This greatly reduces adverse reactions when the titanium alloy urethral stent comes into contact with human tissue, ensuring safety and reliability during long-term use; moreover, the antibacterial effect is long-lasting and does not easily decay.

[0016] 2. The present invention provides a titanium alloy urethral stent with a zinc-zirconium doped coating, which has high stability and can release zinc and zirconium ions for a long time in complex biological environments such as urine, significantly inhibiting the growth of drug-resistant bacteria. It solves the problem of the antibacterial effect decay of the coating during long-term use, while maintaining long-term bactericidal performance, and can effectively deal with common drug-resistant bacteria in human tissue implants.

[0017] 3. This invention uses micro-arc oxidation technology to grow a porous coating with zinc and zirconium doping on the surface of the titanium alloy urethral stent body. This can effectively enhance the mechanical strength of the titanium alloy urethral stent. In addition to antibacterial function, the coating also has good corrosion resistance, wear resistance and bioactivity, which can promote the rapid repair of bone tissue and expand the application of the corresponding materials in orthopedics and other fields to meet different medical needs.

[0018] 4. The titanium alloy urethral stent with zinc-zirconium doped coating provided by the present invention has a simple, environmentally friendly and low-cost preparation process, and can be applied on a large scale to the surface modification of titanium alloy substrates, and has strong industrialization potential. Attached Figure Description

[0019] Figure 1 This is an electron microscope image of the coating in Embodiment 1 of the titanium alloy urethral stent with zinc-zirconium doped coating of the present invention; Figure 2 The images show electron microscope (EM) images of the untreated coating, the conventional zirconium-doped coating, and the zinc-zirconium-doped coating of the present invention, where (a), (b), and (c) are the low-magnification surface morphologies of the three coatings, respectively; (d), (e), and (f) are the high-magnification surface morphologies of the three coatings, respectively; and (g), (h), and (i) are the cross-sectional morphologies of the three coatings, respectively. Figure 3 The images show the pseudo-color height distribution of a conventional zirconium-doped coating and a zinc-zirconium-doped coating of the present invention, where (a) is a three-dimensional surface height map of the conventional zirconium-doped coating, (b) is a two-dimensional pseudo-color height distribution map of the conventional zirconium-doped coating, (c) is a three-dimensional surface height map of the zinc-zirconium-doped coating of the present invention, and (d) is a two-dimensional pseudo-color height distribution map of the zinc-zirconium-doped coating of the present invention. Figure 4The roughness cross-sectional curves of the conventional zirconium-doped coating and the zinc-zirconium-doped coating of the present invention are shown, where (a) is the roughness cross-sectional curve of the conventional zirconium-doped coating and (b) is the roughness cross-sectional curve of the zinc-zirconium-doped coating of the present invention. Figure 5 The images show the colony distribution of bacteria washed from traditional titanium alloy coated samples and zinc-zirconium doped coated samples of the present invention, smeared onto the corresponding agar medium. (a) and (b) are the colony distribution of Escherichia coli washed from traditional titanium alloy coated samples and zinc-zirconium doped coated samples of the present invention, smeared onto the corresponding agar medium, respectively. (c) and (d) are the colony distribution of Staphylococcus aureus washed from traditional titanium alloy coated samples and zinc-zirconium doped coated samples of the present invention, respectively. Figure 6 To co-culture the zinc-zirconium doped coating sample of the present invention with simulated urine, the colony distribution images were obtained by rinsing and smearing the sample onto the corresponding agar medium after 0, 3, 7, and 14 days of culture. Among them, (a)-(d) are the colony distribution images of Escherichia coli after 0, 3, 7, and 14 days of culture, respectively, and (e)-(h) are the colony distribution images of Staphylococcus aureus after 0, 3, 7, and 14 days of culture, respectively. Figure 7 The images show fluorescence staining patterns of Escherichia coli on the surfaces of an untreated coating, a conventional zirconium-doped coating, and the zinc-zirconium-doped coating of this invention. (a), (b), and (c) are fluorescence staining patterns of live Escherichia coli on the three coating surfaces, respectively; (d), (e), and (f) are fluorescence staining patterns of dead Escherichia coli on the three coating surfaces, respectively; and (g), (h), and (i) are superimposed fluorescence staining patterns of live and dead Escherichia coli on the three coating surfaces, respectively. Figure 8 The images show fluorescence staining patterns of Staphylococcus aureus on the surfaces of an untreated coating, a conventional zirconium-doped coating, and the zinc-zirconium-doped coating of this invention. (a), (b), and (c) are fluorescence staining patterns of live Staphylococcus aureus on the three coating surfaces, respectively; (d), (e), and (f) are fluorescence staining patterns of dead Staphylococcus aureus on the three coating surfaces, respectively; and (g), (h), and (i) are superimposed fluorescence staining patterns of live and dead Staphylococcus aureus on the three coating surfaces, respectively. Detailed Implementation

[0020] To make the advantages and features of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] A titanium alloy urethral stent with a zinc-zirconium doped coating includes a titanium alloy urethral stent body and a coating grown on the surface of the titanium alloy urethral stent body using micro-arc oxidation technology. The titanium alloy urethral stent with a zinc-zirconium doped coating of this invention is prepared using the following steps: Step 1: Prepare the electrolyte. The electrolyte can be a phosphate system, a silicate system, or other electrolytes.

[0022] The electrolyte for phosphate systems is usually selected from sodium dihydrogen phosphate or sodium hexametaphosphate. When sodium dihydrogen phosphate or sodium hexametaphosphate is selected, the amount of sodium dihydrogen phosphate or sodium hexametaphosphate added is in the range of 10~30 g / L.

[0023] Then, zirconium salt and zinc salt are added to the electrolyte. The amount of zirconium salt added ranges from 10 to 30 g / L, and the amount of zinc salt added ranges from 10 to 20 g / L.

[0024] Step 2: Prepare a traditional titanium alloy urethral stent and place it in an electrolyte solution containing zirconium and zinc salts, using it as the stent body. Then, employ micro-arc oxidation technology, continuously applying the solution under a high-voltage pulsed electric field for 10-15 minutes. This allows metal ions, oxygen ions, zirconium ions, zinc ions from the electrolyte, and titanium ions from the titanium alloy urethral stent body to grow and form a coating on the surface of the stent body. The titanium alloy urethral stent with a zinc-zirconium doped coating is thus prepared.

[0025] Because the electrolyte contains zirconium and zinc salts, and this invention uses micro-arc oxidation technology to grow a coating on the surface of the titanium alloy urethral stent, the coating prepared by this invention has a porous structure and is doped with zinc and zirconium. In addition to zinc and zirconium, the porous coating also contains oxygen, titanium, and other metal components. The oxygen originates from water in the electrolyte and dissolved oxygen during the micro-arc oxidation process; the titanium comes from the titanium alloy urethral stent itself; and the other metal components mainly originate from the electrolyte (e.g., if the electrolyte is a phosphate system, the main metal component is phosphorus; if the electrolyte is a silicate system, the main metal component is silicon). Variations in voltage, current density, time, and electrolyte during micro-arc oxidation will result in different thicknesses; these parameters can be adjusted during preparation to achieve the desired thickness.

[0026] Example 1 In this embodiment, a sodium dihydrogen phosphate-based electrolyte was selected, with an addition amount of 20 g / L. The zirconium salt was sodium zirconate (Na₂ZrO₃), with an addition amount of 15 g / L, and the zinc salt was sodium zincate (Na₂ZnO₂), with an addition amount of 10 g / L. Other types of zirconium and zinc salts may also be used in other embodiments of the invention. Correspondingly, during the micro-arc oxidation treatment, this embodiment involved continuous operation under a 600 V high-voltage pulsed electric field for 10 minutes. The resulting porous structure with zinc and zirconium doped coating is shown in the electron microscope image below. Figure 1 As shown.

[0027] The porous structure prepared in this embodiment has a zinc and zirconium doped coating. The average thickness at each location was measured to be 10.57 μm. The weight percentages of oxygen, phosphorus, titanium, zirconium, and zinc were 27.11, 16.45, 6.15, 35.61, and 14.68, respectively, and the atomic percentages were 57.07, 17.89, 4.33, 13.15, and 7.56, respectively.

[0028] Example 2 In this embodiment, a sodium dihydrogen phosphate-based electrolyte was selected, with an addition amount of 15 g / L. The zirconium salt was sodium zirconate (Na₂ZrO₃), with an addition amount of 10 g / L, and the zinc salt was sodium zincate (Na₂ZnO₂), with an addition amount of 15 g / L. Accordingly, during the micro-arc oxidation treatment, this embodiment continuously applied the solution under a 550 V high-voltage pulsed electric field for 12 minutes.

[0029] Example 3 In this embodiment, a sodium dihydrogen phosphate-based electrolyte was selected, with an addition amount of 30 g / L. The zirconium salt was sodium zirconate (Na₂ZrO₃), with an addition amount of 30 g / L, and the zinc salt was sodium zincate (Na₂ZnO₂), with an addition amount of 20 g / L. Accordingly, during the micro-arc oxidation treatment, this embodiment continuously applied the solution under a 620 V high-voltage pulsed electric field for 15 minutes.

[0030] Example 4 In this embodiment, a sodium hexametaphosphate-based electrolyte was selected, with an addition amount of 10 g / L. The zirconium salt was sodium zirconate (Na₂ZrO₃), with an addition amount of 16 g / L, and the zinc salt was sodium zincate (Na₂ZnO₂), with an addition amount of 12 g / L. Accordingly, during the micro-arc oxidation treatment, this embodiment continuously applied a 500V high-voltage pulsed electric field for 13 minutes.

[0031] Example 5 In this embodiment, a sodium hexametaphosphate-based electrolyte was selected, with an addition amount of 20 g / L. The zirconium salt was sodium zirconate (Na₂ZrO₃), with an addition amount of 14 g / L, and the zinc salt was sodium zincate (Na₂ZnO₂), with an addition amount of 10 g / L. Accordingly, during the micro-arc oxidation treatment, this embodiment continuously applied the solution under a 500V high-voltage pulsed electric field for 12 minutes.

[0032] The following uses Example 1 as an example to illustrate the structure and effects of the untreated coating, the traditional zirconium-doped coating, and the zinc-zirconium-doped coating of the present invention.

[0033] Figure 2The images show electron microscope (EM) images of the untreated coating, the conventional zirconium-doped coating, and the zinc-zirconium-doped coating of the present invention. (a), (b), and (c) show the low-magnification surface morphology of the untreated coating, the conventional zirconium-doped coating, and the zinc-zirconium-doped coating of the present invention, respectively. (d), (e), and (f) show the high-magnification surface morphology of the untreated coating, the conventional zirconium-doped coating, and the zinc-zirconium-doped coating of the present invention, respectively. (g), (h), and (i) show the cross-sectional morphology of the untreated coating, the conventional zirconium-doped coating, and the zinc-zirconium-doped coating of the present invention, respectively. It can be seen that the untreated coating surface contains only a small number of fine particles, while the conventional zirconium-doped coating and the zinc-zirconium-doped coating of the present invention exhibit numerous micron- to nanometer-scale protrusions and pores, forming a porous structure. However, the high-magnification surface morphology shows that the surface structure of the zinc-zirconium-doped coating of the present invention is more complex, with clear pore boundaries and exhibiting multi-level roughness. Furthermore, the cross-sectional surface morphology shows that the surface boundary of the zinc-zirconium-doped coating of the present invention is smoother and the thickness is more uniform.

[0034] Figure 3 The images show the pseudo-color height distribution of a conventional zirconium-doped coating and the zinc-zirconium-doped coating of the present invention, where (a) is a three-dimensional surface height map of the conventional zirconium-doped coating, (b) is a two-dimensional pseudo-color height distribution map of the conventional zirconium-doped coating, (c) is a three-dimensional surface height map of the zinc-zirconium-doped coating of the present invention, and (d) is a two-dimensional pseudo-color height distribution map of the zinc-zirconium-doped coating of the present invention. Figure 4 The figures show the roughness cross-sectional curves of a conventional zirconium-doped coating and the zinc-zirconium-doped coating of the present invention, where (a) is the roughness cross-sectional curve of the conventional zirconium-doped coating and (b) is the roughness cross-sectional curve of the zinc-zirconium-doped coating of the present invention. Figure 3 , Figure 4 It can be further seen that the surface roughness of the zinc-zirconium doped coating of the present invention is significantly higher than that of the traditional zirconium doped coating, and the surface roughness structure of the zinc-zirconium doped coating of the present invention is more uniformly distributed and has a larger surface area, which provides conditions for subsequent antibacterial and stronger ion release.

[0035] Using Example 1 as an example, specific tests are conducted to illustrate the antibacterial properties, antibacterial durability, and bactericidal effect of the zinc-zirconium doped coating of the present invention.

[0036] First, in vitro tests were performed, culturing drug-resistant Escherichia coli (ETEC) and Staphylococcus aureus (MRSA) to 100 μL. 6Subsequently, 100 μL of each sample was co-cultured with the titanium alloy urethral stent sample with zinc-zirconium doped coating from Example 1 of this invention and a conventional titanium alloy urethral stent sample, resulting in four culture samples. After 24 hours, the four culture samples were fractionally washed with 900 μL of PBS (phosphate buffer), and after dilution 1000 times, 100 μL of each solution was transferred to the corresponding agar medium and spread evenly. The Escherichia coli and Staphylococcus aureus bacteria washed onto the four agar medium were then observed, and the results are as follows: Figure 5 As shown, (a) is a colony distribution diagram of *E. coli* washed from a traditional titanium alloy coated sample and smeared onto the corresponding agar medium; (b) is a colony distribution diagram of *E. coli* washed from a zinc-zirconium doped coated sample of the present invention and smeared onto the corresponding agar medium; (c) is a colony distribution diagram of *Staphylococcus aureus* washed from a traditional titanium alloy coated sample and smeared onto the corresponding agar medium; and (d) is a colony distribution diagram of *Staphylococcus aureus* washed from a zinc-zirconium doped coated sample of the present invention and smeared onto the corresponding agar medium. It can be seen that, during in vitro testing, the zinc-zirconium doped coated sample of the present invention, through the synergistic effect of zirconium and zinc within the coating, can effectively inhibit the growth of *E. coli* and *Staphylococcus aureus*, effectively improving its antibacterial performance.

[0037] Then, a simulated urine test was performed. The zinc-zirconium doped coating sample of the present invention was co-cultured with simulated urine. At day 0 (i.e., before culturing with simulated urine), day 3, day 7, and day 14, the same culturing, rinsing, and observation methods as described above were used to rinse off Escherichia coli and Staphylococcus aureus from the zinc-zirconium doped coating sample and smear it onto the corresponding agar medium. The obtained colony distribution is shown in the figure. Figure 6 As shown. Figure 6 The images show the colony distribution on the zinc-zirconium doped coating samples of this invention after 0, 3, 7, and 14 days of cultivation, respectively. Figure 6 Images (a)-(d) show the colony distribution of *E. coli* at 0, 3, 7, and 14 days of culture, respectively. Figure 6 Images (e)-(h) show the colony distribution of Staphylococcus aureus at 0, 3, 7, and 14 days of culture, respectively. It can be seen that the zinc-zirconium doped coating of this invention, in a simulated urine environment, can release zinc and zirconium ions over a long period, significantly inhibiting the growth of drug-resistant bacteria while maintaining long-lasting antibacterial properties, thus solving the problem of antibacterial effect attenuation during long-term use.

[0038] Finally, a bactericidal test was conducted using live / dead bacteria fluorescent dyes. In the bactericidal test, live bacteria were marked with green fluorescent dots, and dead bacteria were marked with red fluorescent dots. Escherichia coli and Staphylococcus aureus were stained respectively. Figure 7The images show fluorescence staining patterns of Escherichia coli on the surfaces of an untreated coating, a conventional zirconium-doped coating, and the zinc-zirconium-doped coating of the present invention, respectively. (a), (b), and (c) are fluorescence staining patterns of live Escherichia coli on the surfaces of the untreated coating, the conventional zirconium-doped coating, and the zinc-zirconium-doped coating of the present invention, respectively. (d), (e), and (f) are fluorescence staining patterns of dead Escherichia coli on the surfaces of the untreated coating, the conventional zirconium-doped coating, and the zinc-zirconium-doped coating of the present invention, respectively. (g), (h), and (i) are superimposed fluorescence staining patterns of live and dead Escherichia coli on the surfaces of the untreated coating, the conventional zirconium-doped coating, and the zinc-zirconium-doped coating of the present invention, respectively. Figure 8 The images show fluorescence staining patterns of Staphylococcus aureus on the surfaces of an untreated coating, a conventional zirconium-doped coating, and the zinc-zirconium-doped coating of this invention. (a), (b), and (c) show the fluorescence staining patterns of viable Staphylococcus aureus on the untreated coating, the conventional zirconium-doped coating, and the zinc-zirconium-doped coating of this invention, respectively. (d), (e), and (f) show the fluorescence staining patterns of dead Staphylococcus aureus on the untreated coating, the conventional zirconium-doped coating, and the zinc-zirconium-doped coating of this invention, respectively. (g), (h), and (i) are superimposed fluorescence staining patterns of viable and dead Staphylococcus aureus on the untreated coating, the conventional zirconium-doped coating, and the zinc-zirconium-doped coating of this invention, respectively. It can be seen that the untreated coating surface has a dense signal and a large number of viable bacteria. The conventional zirconium-doped coating has fewer viable bacteria compared to the untreated coating surface, while the zinc-zirconium-doped coating of this invention shows a further reduction in viable bacteria. Simultaneously, a large number of red fluorescent dots appear on its surface, indicating the presence of dead bacteria. This demonstrates that the zinc-zirconium-doped coating of this invention has a significant bactericidal effect, and not merely inhibits bacterial growth.

[0039] Electron microscopy analysis was performed on the porous structures with zinc and zirconium doped coatings prepared in Examples 2 to 7, and their electron microscopic structures were similar to those of Example 1. Simultaneously, the titanium alloy urethral stent samples with zinc-zirconium doped coatings in Examples 2 to 7 were subjected to various tests using the same testing methods as in Example 1. The test results showed that the titanium alloy urethral stent samples with zinc-zirconium doped coatings in Examples 2 to 5 also exhibited similar effects to those in Example 1.

[0040] Currently, although some coatings in the industry incorporate metals such as silver and copper, while achieving some antibacterial effects, these coatings suffer from poor stability and limited duration of antibacterial activity, making it difficult to achieve the comprehensive advantages of this invention in terms of resistance to drug-resistant bacteria, stability, and biocompatibility. The present invention's technique of simultaneously incorporating zinc and zirconium into the coating achieves excellent antibacterial effects while improving biocompatibility, resulting in higher stability and durability. This achieves an optimal balance between coating stability and antibacterial properties.

[0041] In addition, traditional surface modification techniques for titanium alloy urethral stents, such as plasma impregnation and sol-gel methods, can also improve the antibacterial properties of the coating. However, compared with micro-arc oxidation technology, these techniques often lag behind in terms of coating uniformity, durability, and control over metal ions. Therefore, this invention employs micro-arc oxidation technology to grow a zinc-zirconium doped coating on the surface of a titanium alloy urethral stent. While ensuring coating stability and biocompatibility, this method not only provides good antibacterial effects but also significant bactericidal effects, offering significant advantages in applications such as urinary system implants and other human tissue implants.

[0042] When the aforementioned titanium alloy urethral stent with zinc-zirconium doped coating is used in the urinary system, it can effectively solve the problems of insufficient antibacterial performance and easy drug resistance of current titanium alloy urethral stents in clinical applications.

[0043] The above description is only used to illustrate the technical solutions of the present invention, and is not intended to limit them. For those skilled in the art, modifications can be made to the specific technical solutions described in the above embodiments, or equivalent substitutions can be made to some of the technical features. However, these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions protected by the present invention.

Claims

1. A titanium alloy urethral stent with a zinc-zirconium doped coating, comprising a titanium alloy urethral stent body and a coating located on the surface of the titanium alloy urethral stent body; characterized in that, Prepared using the following steps: Step 1: Add zirconium salt and zinc salt to the electrolyte, wherein the amount of zirconium salt added is 10~30 g / L and the amount of zinc salt added is 10~20 g / L; Step 2: The titanium alloy urethral stent body is placed in an electrolyte containing zirconium salt and zinc salt. Micro-arc oxidation technology is used to continuously generate micro-arc discharge on the surface of the titanium alloy urethral stent body, thereby growing and forming the coating on the surface of the titanium alloy urethral stent body. The coating is a porous structure and has zinc and zirconium doping.

2. The titanium alloy urethral stent with a zinc-zirconium doped coating according to claim 1, characterized in that: The thickness of the porous structure and the zinc- and zirconium-doped coating is 7~15 μm.

3. The titanium alloy urethral stent with a zinc-zirconium doped coating according to claim 2, characterized in that: The thickness of the porous structure and the zinc- and zirconium-doped coating is 8.5~12 μm.

4. The titanium alloy urethral stent with a zinc-zirconium doped coating according to claim 3, characterized in that: The thickness of the porous structure and the zinc- and zirconium-doped coating is 10.5 μm.

5. The titanium alloy urethral stent with a zinc-zirconium doped coating according to claim 1, characterized in that: The zirconium salt is Na2ZrO3, and its addition amount is 14~16 g / L; The zinc salt is Na2ZnO2, and its addition amount is 10~12g / L.

6. The titanium alloy urethral stent with a zinc-zirconium doped coating according to claim 5, characterized in that: The zirconium salt is Na2ZrO3, and its addition amount is 15g / L; The zinc salt is Na2ZnO2, and its addition amount is 10g / L.

7. A titanium alloy urethral stent with a zinc-zirconium doped coating according to any one of claims 1-6, characterized in that, Step 2 is as follows: A titanium alloy urethral stent is placed in an electrolyte containing zirconium and zinc salts. Micro-arc oxidation technology is used to continuously apply the stent under a high-voltage pulsed electric field for 10-15 minutes, causing continuous micro-arc discharge on the surface of the titanium alloy urethral stent. This allows metal ions, oxygen ions, zirconium ions, zinc ions in the electrolyte, and titanium ions in the titanium alloy urethral stent to grow together and form a porous structure with a zinc and zirconium doped coating.

8. The titanium alloy urethral stent with a zinc-zirconium doped coating according to claim 7, characterized in that: The electrolyte is a phosphate-based electrolyte.

9. A titanium alloy urethral stent with a zinc-zirconium doped coating according to claim 8, characterized in that: The electrolyte is a sodium dihydrogen phosphate-based electrolyte, and the amount of sodium dihydrogen phosphate added is 10~30g / L; Alternatively, the electrolyte is a sodium hexametaphosphate-based electrolyte, with the amount of sodium hexametaphosphate added being 10~30 g / L.

10. A titanium alloy urethral stent with a zinc-zirconium doped coating according to claim 8, characterized in that: The electrolyte is a sodium dihydrogen phosphate-based electrolyte, and the amount of sodium dihydrogen phosphate added is 20 g / L; Alternatively, the electrolyte is a sodium hexametaphosphate-based electrolyte, with the amount of sodium hexametaphosphate added being 20 g / L.

Images