ZN-GA SERIES ALLOY AND ITS PREPARATION METHOD AND APPLICATION

Abstract

The invention discloses a Zn—Ga series alloy and a preparation method and application thereof, belonging to the technical field of medical alloys. The Zn—Ga series alloy includes Zn and Ga, and Ga accounts for 0-30 wt % but not including 0. The preparation method is to mix Zn and Ga or Zn, Ga and trace elements, then to obtain a Zn—Ga series alloy by coating paint after smelting or sintering. The mechanical properties of the prepared Zn—Ga series alloy meet the requirements of the strength and toughness of medical implant materials, and it can be degraded in vivo. It has the dual characteristics of biological corrosion degradation and suitable corrosion rate to provide long-term effective mechanical support.

Claims

1. A Zn—Ga series alloy is characterized in that it comprises Zn and Ga, and Ga accounts for 0-30 wt %, but not including 0.

2. The Zn—Ga series alloy according to claim 1 is characterized in that the Zn—Ga series alloy further includes trace elements, which is at least one of magnesium, calcium, strontium, manganese, titanium, zirconium, germanium, copper, silicon, phosphorus, lithium, silver, tin and rare earth elements.

3. The Zn—Ga series alloy according to claim 2 is characterized in that the trace element accounts for 0-10 wt %.

4. The Zn—Ga series alloy according to claim 1 is characterized in that the surface of the Zn—Ga series alloy is further coated with a degradable polymer coating, a degradable ceramic coating or a degradable drug coating.

5. The Zn—Ga series alloy according to claim 1 is characterized in that the preparation material of the degradable polymer coating is at least one of the following 1) and 2): 1) any one of polycaprolactone, polylactic acid, polyglycolic acid, L-polylactic acid, polycyanoacrylate, polyanhydride, polyphosphazene, polydioxanone, polyhydroxybutyrate and polyhydroxyvalerates; 2) a copolymer of any two or more of polylactic acid, polycaprolactone, polyglycolic acid, L-polylactic acid, polycyanoacrylate, and polydioxanone; the preparation material of the ceramic coating is at least one of hydroxyapatite, tricalcium phosphate or tetracalcium oxyphosphate; the drug coating is at least one of rapamycin and its derivative coatings, paclitaxel coatings, everolimus coatings, sirolimus coatings, mitomycin coatings and antibacterial coatings.

6. A method for preparing a Zn—Ga series alloy according to claim 1 is characterized in that it comprises the following steps: Mix Zn, Ga and the trace elements according to any one of the following methods 1) and 2) to obtain a mixture. 1) Zn and Ga; 2) Zn, Ga and trace elements; the zinc alloy can be obtained according to the following steps a) or b). a) under the protection of CO2 and SF6 atmosphere, the mixture is smelted or sintered, and the zinc alloy is obtained after cooling; b) under the protection of CO2 and SF6 atmosphere, the mixture is smelted or sintered, and the degradable polymer coating, the degradable ceramic coating or the degradable drug coating is coated after cooling to obtain the Zn—Ga series alloy.

7. The method for preparing the Zn—Ga series alloy according to claim 6 is characterized in that it further comprises a step of machining the Zn GA series alloy.

8. The method for preparing a Zn—Ga series alloy according to claim 7 is characterized in that the mechanical processing is at least one of rolling, forging, rapid solidification and extrusion.

9. The method for preparing a Zn—Ga series alloy according to claim 6 is characterized in that the sintering is any one of the following methods—element powder mixed sintering method, pre-alloyed powder sintering method, and self-propagating high-temperature synthesis method.

10. An application of the Zn—Ga series alloy according to claim 1 is characterized in that the Zn—Ga series alloy is used in preparing a body fluid-degradable medical implant.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0067] In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following will briefly introduce the drawings that need to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative labor.

[0068] FIG. 1 shows the cell compatibility test results of Zn—Ga alloy.

DETAILED DESCRIPTION OF THE INVENTION

[0069] Various exemplary embodiments of the present invention will now be described in detail. The detailed description should not be considered as a limitation to the present invention, but should be understood as a more detailed description of certain aspects, characteristics, and embodiments of the present invention.

[0070] It should be understood that the terms described in the present invention are only used to describe specific embodiments and are not used to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper limit and the lower limit of the range is also specifically disclosed. Each smaller range between any stated value or intermediate value within the stated range and any other stated value or intermediate value within the stated range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded from the range.

[0071] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art in the field of the present invention. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe methods and/or materials related to the documents. In the event of conflict with any incorporated document, the content of this manual shall prevail.

[0072] Without departing from the scope or spirit of the present invention, various improvements and changes can be made to the specific embodiments of the present specification, which is obvious to those skilled in the art. Other embodiments derived from the description of the present invention will also be obvious to the skilled person. The specification and examples of this application are only exemplary.

[0073] As used herein, “including”, “included”, “having”, “containing”, etc., are all open terms, which means including but not limited to.

[0074] The percentages used in the following examples are all mass percentages unless otherwise specified.

Example 1. Preparation of as-Cast Zn—Ga Series Alloy

[0075] Using pure Zn (99.99 wt. %) and pure Ga (99.95 wt. %) (purchased from Beijing Cuibailin Nonferrous Metal Technology Development Center) as raw materials. Mixing according to different mass ratios—the mass ratio of Zn to Ga and other trace elements Y(Gd, Nd) is 99:1, 98.5:1.5, 98:2, 97:3, 95:5) and smelting at 550° C. under the protection of CO.sub.2+SF.sub.6 atmosphere. After the raw materials are fully melted, holding for 10 minutes, then using circulating water to cool quickly and the Zn—Ga alloy ingot was prepared.

Example 2. Preparation of Rolled Zn—Ga Series Alloy

[0076] First, prepare as-cast Zn—Ga alloy ingots according to the steps in Example 1. Then, the obtained Zn—Ga alloy ingots were hot rolled, and the ingots were preheated at 250° C. Then, it is rolled repeatedly in a reciprocating mill by hot rolling at a warm rolling temperature of 250° C. and finally rolled to a thickness of 1.5 mm in a finishing mill at 250° C.

Example 3. Preparation of Extruded Zn—Ga Series Alloy

[0077] Follow the steps in 1) or 2) below to prepare.

[0078] 1) First, prepare as-cast Zn—Ga series alloy ingots according to the steps in Example 1 and prepare Zn—Ga series alloy bars by extrusion. Using radial extrusion with an extrusion temperature 200° C. The extrusion ratio is 20. Then a Zn—Ga series alloy bar with a diameter of 10 mm was prepared.

[0079] 2) First, prepare as-cast Zn—Ga series alloy ingots according to the steps in Example 1, and use high vacuum rapid quenching system to prepare rapidly solidified Zn—Ga series alloy thin strips. The specific method is that the raw materials are mixed according to the stated ratio and then a high vacuum rapid quenching system is used to prepare a rapidly solidified Zn—Ga ribbon (temperature 550° C., no hot pressing time). The parameters are feeding amount 2˜8 g, induction heating power 3˜7 kW, nozzle and roller distance 0.80 mm, spray pressure 0.1 MPa, roller speed 2000 r/min and nozzle slit size 1 film×8 mm×6 mm. Then the thin strip is crushed and pressed into a billet. The Zn—Ga series alloy bar is prepared by extrusion. Using radial extrusion with an extrusion temperature 200° C. and an extrusion ratio 20, and then the Zn—Ga series alloy bars with a diameter of 10 mm is prepared.

Example 4. Zn—Ga Series Alloy Mechanical Properties

[0080] The Zn—Ga series alloys, prepared according to the methods of Examples 1-3, were respectively prepared into tensile samples according to ASTM-E8-04 tensile test standard, and then polished by 400#, 800#, 1200# and 2000# SiC sandpaper series. After ultrasonic cleaning in acetone, absolute ethanol and deionized water for 15 minutes, a universal material mechanics testing machine was used to perform a tensile test at room temperature, and the tensile speed was 1 mm/min.

[0081] The tensile properties at room temperature of each sample of the Zn—Ga series alloy are shown in Table 1. From Table 1, it can be seen that the yield strength and tensile strength of the rolled alloy and the extruded alloy are obviously improved compared to the as-cast alloy. At the same time, the elongation has been greatly increased, indicating that the mechanical properties of the material have been further optimized after the deformation process.

TABLE-US-00001 TABLE 1 Zn—Ga alloy tensile mechanical properties data Tensile Yield Sample No strength/MPa strength/MPa Elongation/% Pure zinc ingot 22.32 13.53 0.25 Zn—5Ga ingot 103.38 78.06 1.15 Zn—1Ga—0.5Y 269.21 210.05 26.91 rolled plate Zn—1Ga—0.5Y 290.39 243.60 18.05 bar Zn—1Ga—0.5Y 183.39 135.26 2.57 casting ingot

Example 5. Zn—Ga Alloy Blood Compatibility

[0082] The rolled Zn—Ga alloy of Example 2 was prepared into a 10×10×1.5 mm Zn—Ga alloy sample piece by wire cutting, which was polished by 400#, 800#, 1200# and 2000# SiC sandpaper series. After ultrasonic cleaning for 15 minutes in acetone, absolute ethanol and deionized water, they were dried at 25° C. Fresh blood from healthy volunteers was collected and stored in an anticoagulant tube containing 3.8 wt % sodium citrate as an anticoagulant. Dilute with 0.9% normal saline at a ratio of 4:5 to prepare a diluted blood sample. Soak the sample in 10 mL of normal saline, keep it at 37±0.5° C. for 30 min, add 0.2 mL of diluted blood sample, and keep it at 37±0.5° C. for 60 min. 10 mL of normal saline was used as the negative control group, and 10 mL of deionized water was used as the positive control group. After centrifugation at 3000 rpm for 5 minutes, the supernatant was taken to measure the absorbance OD value with an Unic-7200 UV-Vis spectrophotometer at 545 nm, and three sets of parallel samples were set for statistical analysis.

[0083] Use the following formula to calculate the hemolysis rate:

Hemolysis rate=(experimental group OD value-negative group OD value)/(positive group OD value-negative group OD value)×100%.

[0084] The experimental results show that the hemolysis rate of Zn—Ga alloy is between 0.2% and 0.5%, which is far less than the safety threshold of 5% required for clinical use, and shows good compatibility of red blood cells and hemoglobin.

Example 7. Preparation of Body Fluid Degradable Medical Zn—Ga Implant and its Cell Compatibility Experiment

[0085] The Zn—Ga alloy was prepared according to the method of Examples 1-3. The 6 Zn—Ga alloy blocks prepared above with length, width, and thickness of 10 mm, 10 mm, and 1.5 mm respectively were sterilized by γ-ray and placed in a sterile culture flask. Add MEM cell culture medium at the ratio of sample surface area to MEM cell culture medium volume of 1.25 cm.sup.2/mL, and place it in an incubator at 37° C., 95% relative humidity, and 5% CO.sub.2 for 72 hours to obtain Zn—Ga alloy extraction liquid stock solution. Seal it and keep it in refrigerator at 4° C. for later use.

[0086] Extraction and cell inoculation culture and observation result. MG63 cells (purchased from Guangzhou Genio Biotechnology Co., Ltd.) were resuscitated and passaged, suspended in MEM cell culture medium, and inoculated on 96-well culture plates. The negative control group was added with MEM cell culture medium, and the Zn—Ga alloy extract group was added with the 4-fold diluted Zn—Ga alloy extract obtained above, so that the final cell concentration was 5×10.sup.4/mL. Culture in a 37° C., 5% CO.sub.2 incubator. After 5 days, take out the culture plate and observe the morphology of living cells under an inverted phase contrast microscope (as shown in FIG. 1). The results showed that the cell morphology showed healthy and stretched spindle-shaped convergent growth, indicating that Zn—Ga alloy has excellent cell compatibility.

[0087] The above-mentioned embodiments only describe the preferred modes of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made by those of ordinary skill in the art to the technical solution of the present invention shall fall within the protection scope determined by the claims of the present invention.