Magnesium alloy anastomosis nail material capable of delaying degradation and removing residual stress and preparation method of magnesium alloy anastomosis nail material

Abstract

The invention discloses a magnesium alloy anastomosis nail capable of delaying degradation and removing residual stress and a preparation method. The anastomosis nail comprises an anastomosis nail base body and an oxidation film layer. The anastomosis nail base body is made of magnesium alloy, and the magnesium alloy comprises 1.5%-6% of Zn, 0.01%-0.1% of one or more of Si, Mn, Fe, Cu, Ti, Ni, Al and the like and the balance Mg. An oxidation film layer with a multi-layer structure is formed on the surface of the anastomosis nail through micro-plasma oxidation treatment, so that the anastomosis nail has better corrosion resistance, the degradation speed of the anastomosis nail is delayed, and the implantation requirement of the anastomosis nail in a living body is met. Meanwhile, the residual stress of the bent part is removed in a heat treatment mode, the problem of stress concentration of the bent part is solved, and the phenomenon that the bent part is broken in the deformation process of the anastomosis nail is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of medical device materials, and in particular provides a magnesium alloy stapler with delayed degradation and residual stress removal and a preparation method thereof. Background Art

[0002] Anastomotic staples are mainly used to suture human skin or tissue. Currently, the staples on the market are mainly titanium staples. The material used for titanium staples is titanium alloy. This material cannot degrade by itself after being implanted into the human body. It will remain in the human body for a long time, causing interference with imaging examinations and hindering diagnosis.

[0003] In recent years, biodegradable medical metal materials have developed rapidly and attracted widespread attention. Magnesium alloy, as a representative of these materials, has excellent performance, good biocompatibility, and can be degraded in the human body, avoiding the risks of secondary surgery.

[0004] At present, there are still some problems in the application of magnesium alloys in the biomedical field. Especially in the field of staples, magnesium alloy staples degrade quickly, and there is a potential risk of degradation and failure before achieving medical effects. Especially in the bending part, the stress concentration will be caused in this part during the processing. Not only is there a risk of fracture due to deformation of the bending part of the staples sutured to human tissue when implanted into the human body, but also the bending part degrades faster than other parts of the staples. When degradation occurs, the bending part will degrade and fracture first. Summary of the invention

[0005] The purpose of the present invention is to solve the above problems and provide a magnesium metal anastomotic staple which can delay degradation and remove residual stress and a preparation method thereof.

[0006] The present invention is achieved through the following technical solutions:

[0007] A magnesium alloy stapler for delaying degradation and removing residual stress and a preparation method thereof, the stapler comprising a stapler substrate and an oxide film layer. The stapler substrate is made of a magnesium alloy, and the magnesium alloy composition comprises 1.5-6% Zn, 0.01-0.1% of one or more of Si, Mn, Fe, Cu, Ti, Ni, Al and the like, and the remainder Mg. The surface of the stapler is subjected to microplasma oxidation treatment to form an oxide film layer having a multilayer structure, and the bending part is subjected to heat treatment to remove residual stress.

[0008] Preferably, the staple base is composed of a staple body; staple legs extending from both ends of the staple body toward a direction perpendicular to the staple body; a staple tip at the distal end of the staple leg; and a transition between the staple body and the staple legs: a bending portion.

[0009] Preferably, the oxidizing liquid component used in the microplasma oxidation treatment of the staple surface is a weakly alkaline aqueous solution containing sodium silicate and sodium fluoride.

[0010] Preferably, the microplasma oxidation voltage on the surface of the stapler is 300-400V.

[0011] Preferably, the microplasma oxidation time of the staple surface is 10-20 minutes.

[0012] Preferably, the oxide film layer has a thickness of 5-20 μm.

[0013] Preferably, the heat treatment temperature of the bending portion is 250°C.

[0014] Preferably, the heat treatment time of the bending part is 1-20 minutes.

[0015] Preferably, the material of the heat treatment fixture for the bending portion is a metal material with good thermal conductivity.

[0016] Preferably, a method for preparing a magnesium alloy stapler that delays degradation and removes residual stress is provided, the method specifically comprising:

[0017] 1) subjecting the magnesium alloy ingot to homogenization treatment at 400-500° C. for 4-12 hours;

[0018] 2) Processing the ingot into a round ingot with a diameter of 20-40 mm and removing the surface oxide layer;

[0019] 3) Extruding the magnesium alloy ingot into magnesium alloy rods with a diameter of 1-2.5 mm through two passes with different deformation amounts;

[0020] 4) The obtained magnesium alloy rod is subjected to multiple drawing deformation and annealing to obtain a magnesium alloy wire with a diameter of 0.25-0.3 mm;

[0021] 5) immersing the magnesium alloy wire in an oxidizing solution for micro plasma oxidation treatment;

[0022] 6) processing the magnesium alloy wire treated in step 5) into a magnesium alloy anastomotic staple;

[0023] 7) The processed magnesium alloy bending part is heat treated to remove residual stress, so as to obtain a magnesium alloy staple which can delay degradation and remove residual stress.

[0024] The beneficial effects of the present invention are:

[0025] 1. The present invention forms an oxide film layer with a multi-layer structure by performing microplasma oxidation treatment on the surface of the staple, so that the staple has better corrosion resistance, slows down the degradation rate of the staple, and ensures the implantation requirements of the staple in the organism.

[0026] 2. The present invention removes residual stress at the bending part by heat treatment, thereby solving the problem of stress concentration at the bending part and avoiding the fracture of the anastomotic staple at the bending part during the deformation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0028] Figure 1 It is a structural schematic diagram of a magnesium alloy anastomotic staple capable of delaying degradation and removing residual stress and a preparation method embodiment disclosed in the present invention;

[0029] Figure 2 The present invention is a schematic diagram of a micro plasma oxidation device for a magnesium alloy anastomotic staple capable of delaying degradation and removing residual stress and an embodiment of a preparation method thereof.

[0030] Figure 3 The present invention is an overall schematic diagram of a heat treatment fixture for the bending part of a magnesium alloy anastomotic staple capable of delaying degradation and removing residual stress and an embodiment of a preparation method thereof.

[0031] Figure 4 The present invention is a partial schematic diagram of a heat treatment fixture for the bending part of a magnesium alloy anastomotic staple capable of delaying degradation and removing residual stress and an embodiment of a preparation method thereof.

[0032] Figure 5 The present invention is a schematic front view of a heat treatment fixture for the bending part of a magnesium alloy anastomotic staple capable of delaying degradation and removing residual stress and an embodiment of a preparation method thereof.

[0033] In the figure: 1. nail tip, 2. nail leg, 3. nail body, 4. bending part, 5. fixture body, 6. fixture cover, 7. magnesium alloy anastomosis nail, 8. fixture hollow part, 9. power supply, 10. voltage regulating system, 11. magnesium alloy wire, 12. agitator, 13. cooling system, 14. cathode, 15. oxidation tank. DETAILED DESCRIPTION

[0034] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0035] A magnesium alloy stapler for delaying degradation and removing residual stress and a preparation method thereof, the stapler comprising a stapler substrate and an oxide film layer. The stapler substrate is made of a magnesium alloy, and the magnesium alloy composition comprises 1.5-6% Zn, 0.01-0.1% of one or more of Si, Mn, Fe, Cu, Ti, Ni, Al and the like, and the remainder Mg. The surface of the stapler is subjected to microplasma oxidation treatment to form an oxide film layer having a multilayer structure, and the bending part is subjected to heat treatment to remove residual stress.

[0036] For further explanation, see Figure 1 The staple base is composed of a staple body 3; staple legs 2 extending from both ends of the staple body 3 toward a direction perpendicular to the staple body; a staple tip 1 at the distal end of the staple leg 2; and a transition portion 4 between the staple body 3 and the staple leg 2.

[0037] Further explanation: the oxidizing liquid component used in the microplasma oxidation treatment of the staple surface is a weak alkaline aqueous solution containing sodium silicate and sodium fluoride.

[0038] Furthermore, the microplasma oxidation voltage on the surface of the stapler is 300-400V.

[0039] Furthermore, the microplasma oxidation time of the staple surface is 10-20 minutes.

[0040] Furthermore, the oxide film layer has a thickness of 5-20 μm.

[0041] Further explanation: the heat treatment temperature of the bending part is 250°C.

[0042] Furthermore, the heat treatment time of the bending part is 1-20 minutes.

[0043] Furthermore, the material of the heat treatment fixture for the bending portion is a metal material with good thermal conductivity.

[0044] Further description, a method for preparing a magnesium alloy stapler for delaying degradation and removing residual stress comprises the following steps:

[0045] 1) subjecting the magnesium alloy ingot to homogenization treatment at 400-500° C. for 4-12 hours;

[0046] 2) Processing the ingot into a round ingot with a diameter of 20-40 mm and removing the surface oxide layer;

[0047] 3) Extruding the magnesium alloy ingot into magnesium alloy rods with a diameter of 1-2.5 mm through two passes with different deformation amounts;

[0048] 4) The obtained magnesium alloy rod is subjected to multiple drawing deformation and annealing to obtain a magnesium alloy wire with a diameter of 0.25-0.3 mm;

[0049] 5) immersing the magnesium alloy wire in an oxidizing solution for micro plasma oxidation treatment;

[0050] 6) processing the magnesium alloy wire treated in step 5) into a magnesium alloy anastomotic staple;

[0051] 7) The processed magnesium alloy bending part is heat treated to remove residual stress, so as to obtain a magnesium alloy staple which can delay degradation and remove residual stress.

[0052] The following is a further description of a method for preparing a magnesium alloy staple with delayed degradation and residual stress removal according to the present invention in conjunction with the embodiments and the accompanying drawings:

[0053] Example 1

[0054] In this embodiment, a method for preparing a magnesium alloy stapler for delaying degradation and removing residual stress comprises the following steps:

[0055] Step 1: subjecting the magnesium alloy ingot to homogenization treatment at 400°C for 6 hours;

[0056] Step 2: Process the ingot into a round ingot with a diameter of 20 mm and remove the surface oxide layer;

[0057] Step 3: The magnesium alloy ingot is transformed into a magnesium alloy rod with a diameter of 5 mm through a first extrusion process, and then transformed into a magnesium alloy rod with a diameter of 1 mm through a second extrusion process;

[0058] Step 4: The obtained magnesium alloy rod is subjected to multiple drawing deformation and annealing to obtain a magnesium alloy wire with a diameter of 0.25 mm;

[0059] Step 5: Reference Figure 2 , pour a weak alkaline aqueous solution containing sodium silicate and sodium fluoride into the oxidation tank 15, stir the oxidation solution evenly through the stirrer 12, immerse the magnesium alloy wire 11 in the oxidation solution, so that the magnesium alloy wire 11 and the cathode 14 form positive and negative electrodes, turn on the power supply 9, adjust the voltage to 300V through the voltage regulating system 10, perform micro plasma oxidation treatment on the magnesium alloy wire 11, and the oxidation time is 10 minutes, so that a dense oxide film is formed on the surface of the magnesium alloy wire 11. During the reaction, the cooling system 13 regulates the overall temperature of the oxidation solution within a range to prevent the oxidation solution temperature from being too high.

[0060] Step 6: Processing the magnesium alloy wire 11 processed in step 5 into a magnesium alloy anastomotic staple 7;

[0061] Step 7: Reference Figure 3 , Figure 4 , Figure 5The clamp body 5 and the clamp cover 6 are made of copper blocks. The processed magnesium alloy staples 7 are placed in the clamp body 5. The clamp body has 10 rows in total. A single row can hold up to 50 magnesium alloy staples. The magnesium alloy staples 7 are fixed to the clamp body 5 through the clamp cover 6. A clamp hollow portion 8 is formed between the clamp cover 6 and the clamp body 7. The bent portion 4 of the magnesium alloy staple 7 is in contact with the clamp, and the remaining portion of the magnesium alloy staple 7 is in contact with the air. The clamp is placed in a device with a temperature of 250°C. Due to the difference in thermal conductivity between metal and air, the bent portion 4 is heat treated for 5 minutes. A magnesium alloy staple (7) that can delay degradation and remove residual stress is obtained.

[0062] The thickness of the oxide layer of the magnesium alloy anastomotic staple (7) is 10 μm.

[0063] The magnesium alloy staple (7) was immersed in PBS simulated body fluid and maintained its intact structure for 20 days, and completely degraded for 50 days.

[0064] Example 2

[0065] In this embodiment, a method for preparing a magnesium alloy stapler for delaying degradation and removing residual stress comprises the following steps:

[0066] Step 1: homogenizing the magnesium alloy ingot at 450°C for 8 hours;

[0067] Step 2: Process the ingot into a round ingot with a diameter of 30 mm and remove the surface oxide layer;

[0068] Step 3: The magnesium alloy ingot is transformed into a magnesium alloy rod with a diameter of 4 mm through a first extrusion process, and then transformed into a magnesium alloy rod with a diameter of 1.5 mm through a second extrusion process;

[0069] Step 4: The obtained magnesium alloy rod is subjected to multiple cold and hot alternating drawing deformations to obtain a magnesium alloy wire with a diameter of 0.26 mm;

[0070] Step 5: Reference Figure 2 , pour a weak alkaline aqueous solution containing sodium silicate and sodium fluoride into the oxidation tank 15, stir the oxidation solution evenly through the stirrer 12, immerse the magnesium alloy wire 11 in the oxidation solution, so that the magnesium alloy wire 11 and the cathode 14 form positive and negative electrodes, turn on the power supply 9, adjust the voltage to 350V through the voltage regulating system 10, perform micro plasma oxidation treatment on the magnesium alloy wire 11, and the oxidation time is 15 minutes, so that a dense oxide film is formed on the surface of the magnesium alloy wire 11. During the reaction, the cooling system 13 regulates the overall temperature of the oxidation solution within a range to prevent the oxidation solution temperature from being too high.

[0071] Step 6: Processing the magnesium alloy wire 11 processed in step 5 into a magnesium alloy anastomotic staple 7;

[0072] Step 7: Reference Figure 3 , Figure 4 , Figure 5 The clamp body 5 and the clamp cover 6 are made of aluminum blocks. The processed magnesium alloy staples 7 are placed in the clamp body 5. The clamp body has 10 rows in total, and a single row can hold up to 50 magnesium alloy staples. The magnesium alloy staples 7 are fixed to the clamp body 5 through the clamp cover 6. A clamp hollow part 8 is formed between the clamp cover 6 and the clamp body 7, so that the bending part 4 of the magnesium alloy staple 7 is in contact with the clamp, and the remaining parts of the magnesium alloy staple 7 are in contact with the air. The clamp is placed in a device with a temperature of 250°C. Due to the difference in thermal conductivity between metal and air, the bending part 4 is heat treated for 10 minutes, and a magnesium alloy staple 7 that can delay degradation and remove residual stress is obtained.

[0073] The thickness of the oxide layer of the magnesium alloy staple 7 is 15 μm.

[0074] The magnesium alloy staple 7 was immersed in PBS simulated body fluid and maintained its intact structure for 25 days, and was completely degraded for 55 days.

[0075] Example 3

[0076] In this embodiment, a method for preparing a magnesium alloy stapler for delaying degradation and removing residual stress comprises the following steps:

[0077] Step 1: subjecting the magnesium alloy ingot to homogenization treatment at 500°C for 10 hours;

[0078] Step 2: Process the ingot into a round ingot with a diameter of 40 mm and remove the surface oxide layer;

[0079] Step 3: The magnesium alloy ingot is transformed into a magnesium alloy rod with a diameter of 3 mm through a first extrusion process, and then transformed into a magnesium alloy rod with a diameter of 2 mm through a second extrusion process;

[0080] Step 4: The obtained magnesium alloy rod is subjected to multiple cold and hot alternating drawing deformations to obtain a magnesium alloy wire with a diameter of 0.27 mm;

[0081] Step 5: Reference Figure 2 , pour a weak alkaline aqueous solution containing sodium silicate and sodium fluoride into the oxidation tank 15, stir the oxidation solution evenly through the stirrer 12, immerse the magnesium alloy wire 11 in the oxidation solution, so that the magnesium alloy wire 11 and the cathode 14 form positive and negative electrodes, turn on the power supply 9, adjust the voltage to 380V through the voltage regulating system 10, perform micro plasma oxidation treatment on the magnesium alloy wire 11, and the oxidation time is 20 minutes, so that a dense oxide film is formed on the surface of the magnesium alloy wire 11. During the reaction, the cooling system 13 regulates the overall temperature of the oxidation solution within a range to prevent the oxidation solution temperature from being too high.

[0082] Step 6: Processing the magnesium alloy wire 11 processed in step 5 into a magnesium alloy anastomotic staple 7;

[0083] Step 7: Reference Figure 3 , Figure 4 , Figure 5 The clamp body 5 and the clamp cover 6 are made of silver blocks. The processed magnesium alloy staples 7 are placed in the clamp body 5. The clamp body has 10 rows in total, and a single row can hold up to 50 magnesium alloy staples. The magnesium alloy staples 7 are fixed to the clamp body 5 through the clamp cover 6. A clamp hollow part 8 is formed between the clamp cover 6 and the clamp body 7, so that the bending part 4 of the magnesium alloy staple 7 is in contact with the clamp, and the remaining parts of the magnesium alloy staple 7 are in contact with the air. The clamp is placed in a device with a temperature of 250°C. Due to the difference in thermal conductivity between metal and air, the bending part 4 is heat treated for 15 minutes, and a magnesium alloy staple 7 that can delay degradation and remove residual stress is obtained.

[0084] The thickness of the oxide layer of the magnesium alloy staple 7 is 20 μm.

[0085] The magnesium alloy staple 7 was immersed in PBS simulated body fluid and maintained its intact structure for 30 days, and was completely degraded for 60 days.

[0086] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations within the meaning and scope of the elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A magnesium alloy stapler for delaying degradation and removing residual stress and a preparation method thereof, characterized in that: The stapler comprises a stapler substrate and an oxide film layer. The stapler substrate is made of a magnesium alloy, which contains 1.5-6% Zn, 0.01-0.1% of one or more of Si, Mn, Fe, Cu, Ti, Ni, Al and the like, and a balance of Mg. The surface of the stapler is subjected to microplasma oxidation treatment to form an oxide film layer having a multi-layer structure, and the bending portion (4) is subjected to heat treatment to remove residual stress.

2. The magnesium alloy stapler for delaying degradation and removing residual stress according to claim 1, characterized in that: The anastomotic staple base is composed of a staple body (3), a staple leg (2), a staple tip (1) and a bending portion (4); Nail legs (2) extending from both ends of the nail body (3) in a vertical direction close to the nail body (3), nail tips (1) at the far ends of the nail legs (2) and transitions between the nail body (3) and the nail legs (2).

3. The magnesium alloy stapler for delaying degradation and removing residual stress according to claim 1, characterized in that: The oxidizing liquid component used in the micro-plasma oxidation treatment of the staple surface is a weak alkaline aqueous solution containing sodium silicate and sodium fluoride.

4. The magnesium alloy stapler for delaying degradation and removing residual stress according to claim 1, characterized in that: The microplasma oxidation voltage on the staple surface is 300-400V.

5. The magnesium alloy staple for delaying degradation and removing residual stress according to claim 1, characterized in that: The microplasma oxidation time of the stapler surface is 10-20 minutes.

6. The magnesium alloy staple for delaying degradation and removing residual stress according to claim 1, characterized in that: The oxide film layer has a thickness of 5-20 μm.

7. The magnesium alloy staple for delaying degradation and removing residual stress according to claim 1, characterized in that: The heat treatment temperature of the bending part (4) is 250°C, and the heat treatment time of the bending part (4) is 1-20 minutes.

8. The magnesium alloy staple for delaying degradation and removing residual stress according to claim 1, characterized in that: The material of the heat treatment fixture of the bending portion (4) is a metal material with good thermal conductivity.

9. The method for preparing a magnesium alloy staple for delaying degradation and removing residual stress according to claim 1, characterized in that: The method is as follows: S1: subjecting the magnesium alloy ingot to homogenization treatment at 400-500°C for 4-12 hours; S2: Processing the ingot into a round ingot with a diameter of 20-40 mm and removing the surface oxide layer; S3: extruding the magnesium alloy ingot into a magnesium alloy rod with a diameter of 1-2.5 mm through two passes with different deformation amounts; S4: The obtained magnesium alloy rod is subjected to multiple drawing deformation and annealing to obtain a magnesium alloy wire with a diameter of 0.25-0.3 mm; S5: immersing the magnesium alloy wire in an oxidizing solution for micro plasma oxidation treatment; S6: processing the magnesium alloy wire treated in step 5) into a magnesium alloy anastomotic staple; S7: heat-treating the processed magnesium alloy bending part (4) to remove residual stress, thereby obtaining a magnesium alloy staple that can delay degradation and remove residual stress.

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