Coating for degradable zn alloy rivets for meniscus staplers

Abstract

The application discloses a coating of a degradable Zn alloy rivet for a meniscus suture device, which comprises the following components in percentage by mass: Zn 10-30 wt.%, Cu 5-20 wt.% and the rest is Sr; and is prepared through the steps of alloying, pouring, solid solution heat treatment and magnetron sputtering. The Sr-Zn-Cu coating can effectively control the degradation speed of the degradable Zn alloy rivet for the meniscus suture device.

Description

Technical Field

[0001] This invention belongs to the field of medical metal materials, specifically relating to a Sr-Zn-Cu coating for biodegradable Zn alloy rivets used in meniscus suture devices. Background Technology

[0002] Currently, most meniscus suture rivets on the market are made of PEEK material. However, PEEK rivets are permanent implants, causing a foreign body sensation after implantation and making the area around the rivet prone to inflammation, potentially requiring a second surgery. This not only increases the patient's financial burden but also raises surgical risks. Due to the low strength of PEEK material (tensile yield strength around 90 MPa, flexural strength around 110 MPa), the rivets are large, resulting in significant postoperative tissue damage. Researchers have begun developing biodegradable metal materials to replace PEEK in the manufacture of meniscus suture rivets. Biodegradable metals possess excellent mechanical properties, allowing for the creation of smaller meniscus suture rivets, reducing inflammation and tissue damage.

[0003] Over the past 20 years, researchers have conducted extensive studies on magnesium (Mg) and iron (Fe)-based biodegradable alloys. However, magnesium-based alloys degrade too quickly, often causing implants to prematurely lose their complete mechanical properties; while iron-based alloys corrode too slowly in the human body environment, leading to problems similar to those of permanent metal implants. Researchers have further developed zinc-based alloys to overcome the limitations of iron and magnesium-based alloys, and zinc-based alloys offer adjustable mechanical properties and corrosion rates.

[0004] However, when using zinc alloy to make biodegradable meniscus suture rivets, the rivets degrade too quickly (0.3 mm / month), causing them to lose strength after a certain period and failing to promote tissue healing. Therefore, there is an urgent need to research and develop a coating for biodegradable Zn alloy rivets used in meniscus suture devices to effectively control the degradation rate. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a Sr-Zn-Cu coating for biodegradable Zn alloy rivets for meniscus suture devices, which can effectively control the degradation rate of biodegradable Zn alloy rivets for meniscus suture devices.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] A Sr-Zn-Cu coating for biodegradable Zn alloy rivets used in meniscus suture devices comprises, by weight percentage: Zn 10–30 wt.%, Cu 5–20 wt.%, with the balance being Sr. The purity of the Zn is 99.99 wt.%, the purity of the Sr is 99.99 wt.%, and the purity of the Cu is 99.99 wt.%.

[0008] Furthermore, the preferred composition range for the Sr-Zn-Cu coating is: Zn 15-20 wt.%, Cu 10-15 wt.%, with the remainder being Sr.

[0009] The method for preparing the Sr-Zn-Cu coating for the biodegradable Zn alloy rivets used in meniscus suture devices includes the following steps:

[0010] (1) Alloy melting: The raw materials pure Sr, pure Zn and pure Cu are mixed according to the designed composition content and placed in a vacuum induction heating furnace for melting;

[0011] (2) Casting: After the raw materials are melted, they are cast to obtain Sr-Zn-Cu alloy ingots;

[0012] (3) Solution heat treatment: Sr-Zn-Cu alloy ingots are solution treated in a heat-holding furnace and then air-cooled to room temperature to reduce compositional segregation and obtain Sr-Zn-Cu alloy ingots with uniform composition.

[0013] (4) Surface modification: Electron beam pulse surface modification was performed on the biodegradable Zn alloy rivets of the meniscus suture device. The electron beam pulse surface modification parameters were: 30 to 120 pulses and 10 to 90 seconds pulse interval. Through electron beam pulse surface modification, the surface roughness of the rivets was increased to increase the coating adhesion.

[0014] (5) Magnetron sputtering: Using DC magnetron sputtering in PVD, Sr-Zn-Cu alloy ingots are made into target materials and fixed on the cathode; biodegradable Zn alloy rivets of meniscus suture are placed on the anode facing the target, and Sr-Zn-Cu coating is formed on the surface of biodegradable Zn alloy rivets of meniscus suture by magnetron sputtering.

[0015] In step (5), the thickness of the Sr-Zn-Cu coating is 1 to 10 μm.

[0016] The principle of this invention is as follows: (1) The Sr-Zn-Cu coating of this invention is used on the surface of the biodegradable Zn alloy rivet of the meniscus suture device. The coating uses Sr as the matrix material. Sr element can improve the biocompatibility and mechanical properties of biodegradable metals, promote tissue healing, and reduce the degradation rate. The addition of Zn to the coating components can enhance the bonding strength with the matrix, and the coating is not easy to fall off. Cu element in the coating components has good antibacterial properties, which can prevent bacteria from adhering to the surface of the implant, reduce the tendency of pitting corrosion, and slow down the strength decay during the degradation process, so that the biodegradable Zn alloy rivet of the meniscus suture device can play a role in tissue healing. (2) This invention uses electron beam surface technology to treat the rivet, and then DC magnetron sputtering is used to make the Sr-Zn-Cu coating. The coating after magnetron sputtering is more uniform and has stronger adhesion, which can more effectively control the degradation rate of Zn alloy rivets.

[0017] Compared with the prior art, the present invention has the following advantages and effects:

[0018] (1) The invention of Sr-Zn-Cu alloy coating reduces the degradation rate of biodegradable Zn alloy rivets in meniscus suture devices, improves the bonding strength and antibacterial rate of the coating, and makes the degradation rate of rivets match the tissue healing rate, thus perfectly realizing the function of biodegradable Zn alloy meniscus suture device rivets.

[0019] (2) The use of electron beam surface treatment technology to treat rivets greatly improves the surface roughness and surface condition of the substrate compared with the existing technology (without electron beam treatment), resulting in higher coating bonding strength and thus enabling the coating to more effectively control the degradation rate of biodegradable Zn alloy rivets.

[0020] (3) The Sr-Zn-Cu coating is fabricated by DC magnetron sputtering, which produces a more uniform coating and stronger adhesion than the general physical vapor deposition method. Detailed Implementation

[0021] To facilitate understanding of the present invention, specific embodiments will be described in detail below. These embodiments will help those skilled in the art to further understand the present invention; however, they are not intended to limit the invention in any way. It should be noted that those skilled in the art can make various modifications and improvements to the present invention without departing from its conceptual framework, and these modifications and improvements all fall within the scope of protection of the present invention. Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods. Unless otherwise specified, the materials and reagents used in the following embodiments are commercially available.

[0022] Example 1

[0023] A Sr-Zn-Cu coating for biodegradable Zn alloy rivets used in meniscus suture devices comprises the following components by mass percentage: Zn 10%, Cu 5%, Sr 85%; the raw materials are pure zinc (99.99 wt.%), pure strontium (99.99 wt.%), and pure copper (99.99 wt.%); the parameters for electron beam pulse surface modification of the meniscus suture device rivets are: 30 pulses and a pulse interval of 90 s; the Sr-Zn-Cu coating thickness obtained by magnetron sputtering is approximately 10 μm. Preparation parameters and coating properties are shown in Table 1.

[0024] Example 2

[0025] A Sr-Zn-Cu coating for biodegradable Zn alloy rivets used in meniscus suture devices comprises the following components by mass percentage: Zn 10%, Cu 20%, and Sr 70%. The parameters for electron beam pulse surface modification of the meniscus suture device rivets were: 120 pulses and a pulse interval of 10 s; the Sr-Zn-Cu coating thickness obtained by magnetron sputtering was approximately 1 μm. Preparation parameters and coating properties are shown in Table 1.

[0026] Example 3

[0027] A Sr-Zn-Cu coating for biodegradable Zn alloy rivets used in meniscus suture devices comprises the following components by mass percentage: Zn 30%, Cu 20%, and Sr 50%. The parameters for electron beam pulse surface modification of the meniscus suture device rivets were: 60 pulses and a pulse interval of 90 s; the Sr-Zn-Cu coating thickness obtained by magnetron sputtering was approximately 4 μm. Preparation parameters and coating properties are shown in Table 1.

[0028] Example 4

[0029] A Sr-Zn-Cu coating for biodegradable Zn alloy rivets used in meniscus suture devices comprises the following components by mass percentage: Zn 15%, Cu 10%, and Sr 75%. The parameters for electron beam pulse surface modification of the meniscus suture device rivets were: 60 pulses and a pulse interval of 60 s; the Sr-Zn-Cu coating thickness obtained by magnetron sputtering was approximately 3 μm. Preparation parameters and coating properties are shown in Table 1.

[0030] Example 5

[0031] A Sr-Zn-Cu coating for biodegradable Zn alloy rivets used in meniscus suture devices comprises the following components by mass percentage: Zn 15%, Cu 15%, and Sr 70%. The parameters for electron beam pulse surface modification of the meniscus suture device rivets were: 80 pulses and a pulse interval of 50 s; the Sr-Zn-Cu coating thickness obtained by magnetron sputtering was approximately 5 μm. Preparation parameters and coating properties are shown in Table 1.

[0032] Example 6

[0033] A Sr-Zn-Cu coating for biodegradable Zn alloy rivets used in meniscus suture devices comprises the following components by mass percentage: Zn 20%, Cu 15%, and Sr 65%. The parameters for electron beam pulse surface modification of the meniscus suture device rivets were: 90 pulses and a pulse interval of 40 s; the Sr-Zn-Cu coating thickness obtained by magnetron sputtering was approximately 7 μm. Preparation parameters and coating properties are shown in Table 1.

[0034] Comparative Example 1

[0035] Comparative Example 1 shows the case of a biodegradable Zn alloy rivet for a meniscus suture device without a coating; performance parameters are shown in Table 1. As can be seen from Table 1, the Sr-Zn-Cu coating formed on the biodegradable Zn alloy rivet of the meniscus suture device in this invention effectively controls the degradation rate of the Zn alloy rivet, reducing it from 0.3 mm / month without the coating to 0.027 mm / month with the coating. This ensures that the degradation rate of the biodegradable Zn alloy rivet matches the tissue healing rate, thus better promoting tissue healing. Furthermore, the Sr-Zn-Cu coating of this invention can effectively improve the antibacterial rate of the biodegradable Zn alloy rivet, increasing it from 65% to 99%.

[0036] Table 1. Performance of Sr-Zn-Cu coating for biodegradable Zn alloy rivets used in meniscus suture devices.

[0037]

[0038] Comparative Examples 2-4

[0039] In the coating preparation process, the meniscus suture rivet was not subjected to electron beam pulse surface modification. Other steps were the same as in Examples 4, 5, and 6, and the resulting coating properties are shown in Table 2. As can be seen from Table 2, the present invention uses electron beam pulse to modify the surface of the meniscus suture rivet, changing the surface roughness and surface state of the substrate to increase the bonding strength between the coating and the substrate, thereby enabling the coating to more effectively control the degradation rate of the biodegradable Zn alloy rivet.

[0040] Table 2 Comparison of biodegradable Zn alloy rivets for meniscus suture devices with and without surface modification.

[0041]

[0042] It is understood that the above specific description of the present invention is only for illustrating the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Those skilled in the art should understand that local modifications or equivalent substitutions can still be made to the present invention to achieve the same technical effect; as long as the use needs are met, they are all within the protection scope of the present invention.

Claims

1. A Sr-Zn-Cu coating for biodegradable Zn alloy rivets used in meniscus suture devices, characterized in that: The coating comprises, by mass percentage: Zn 10–30 wt.%, Cu 5–20 wt.%, with the remainder being Sr; the Sr-Zn-Cu coating is prepared by the following steps: (1) Alloy melting: The raw materials, pure Sr, pure Zn and pure Cu, are mixed according to the designed composition content and placed in a vacuum induction heating furnace for melting; (2) Casting: After the raw materials are melted, they are cast to obtain Sr-Zn-Cu alloy ingots; (3) Solution heat treatment: Sr-Zn-Cu alloy ingots are solution treated in a holding furnace and then air-cooled to room temperature to reduce compositional segregation and obtain Sr-Zn-Cu alloy ingots with uniform composition. (4) Surface modification: Electron beam pulse surface modification was performed on the biodegradable Zn alloy rivets of the meniscus suture device. The electron beam pulse surface modification parameters were: 30 to 120 pulses and 10 to 90 seconds pulse interval. (5) Magnetron sputtering: Using DC magnetron sputtering in PVD, Sr-Zn-Cu alloy ingots are made into target materials and fixed on the cathode; biodegradable Zn alloy rivets of meniscus suture are placed on the anode facing the target, and Sr-Zn-Cu coating is formed on the surface of biodegradable Zn alloy rivets of meniscus suture by magnetron sputtering.

2. The Sr-Zn-Cu coating for biodegradable Zn alloy rivets used in meniscus suture devices according to claim 1, characterized in that: The purity of Zn is 99.99 wt.%, the purity of Sr is 99.99 wt.%, and the purity of Cu is 99.99 wt.%.

3. The Sr-Zn-Cu coating for biodegradable Zn alloy rivets used in meniscus suture devices according to claim 1, characterized in that: The composition range of the Sr-Zn-Cu coating is: Zn 15-20 wt.%, Cu 10-15 wt.%, and the remainder is Sr.

4. The Sr-Zn-Cu coating for biodegradable Zn alloy rivets used in meniscus suture devices according to claim 1, characterized in that: In step (5), the thickness of the Sr-Zn-Cu coating is 1~10μm.

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