CN104762645B - Medical implant material and preparation method thereof - Google Patents

Abstract

The invention discloses a method for treating the surface of a medical metal implant material, which belongs to the field of implant processing and preparation in biomedical material engineering. In this method, the medical metal matrix material is used as the cathode, and the oxide ceramic film rich in calcium and phosphorus is prepared on the surface of the medical metal implant by means of cathode plasma electrolytic deposition technology; then the calcium and phosphorus components in the film are converted into hydroxyl by hydrothermal treatment Apatite, forming a hydroxyapatite/oxide composite ceramic film layer. The method is simple, the equipment used is consistent with the traditional plasma electrolytic oxidation equipment, and the prepared film layer is firmly combined with the substrate, which can effectively improve the biological activity of the substrate material, inhibit the precipitation of harmful ions in the substrate material, and improve biocompatibility and safety. At the same time, it broadens the selection range of medical metal matrix materials.

Description

Medical implant material and its preparation method

technical field

The invention belongs to the technical field of surface modification of medical metal materials, in particular to a medical implant material and a preparation method thereof.

Background technique

Biomedical metal materials, also known as surgical implant metal materials, have high mechanical strength and fatigue resistance, and are the most widely used load-bearing implant materials in clinical applications. Compared with bioceramics and biopolymer materials, biomedical metal materials have high strength, good toughness, bending fatigue resistance, excellent processing performance and many other excellent properties that cannot be replaced by other medical materials. Medical metal materials for clinical application mainly include stainless steel, cobalt-chromium alloy, titanium alloy and memory alloy. In addition, there are shape memory alloys, precious metals, and pure metals such as tantalum, niobium, and zirconium. There are many kinds of medical metal materials, but there are two common problems in clinical medicine. First, after the medical metal materials are implanted into the human body, the corrosion of the physiological environment will cause the metal ions to diffuse to the surrounding tissues, resulting in toxic side effects of the surrounding tissues. Typical examples are toxic ions such as nickel, cobalt, and chromium. Studies have found that nickel, cobalt, and chromium plasma all have sensitization reactions to the human body. When the chromium element in steel is in the hexavalent state, it also has a greater tendency of toxicity and allergies to the human body. The enrichment of nickel ions is very toxic to the human body, has allergic reactions, and may induce mutations and canceration in organisms. Second, when used for hard tissue implant materials, especially for bone implant materials and bone substitute materials, medical metal materials are generally biologically inert and cannot form direct osseointegration with surrounding tissues. Therefore, in order to make the medical metal material implanted in the body fully exert its function, it is best to carry out surface modification on its surface. On the one hand, it improves the corrosion resistance and wear resistance of the surface, improves its biological characteristics to reduce biological toxicity; on the other hand, it endows the material with biological activity, improves the binding ability of the material and bone tissue, strengthens osseointegration, and makes the material more Good biocompatibility and biocompatibility. This is also an urgent problem to be solved in the clinical application of medical metal materials, and it is also an important research direction in the field of medical metal materials.

Implant materials are in direct contact with tissues, and their interface properties are particularly important. Therefore, using surface modification to improve the biocompatibility of medical metal materials will be the development trend of medical metal materials in the future. Scholars at home and abroad have carried out more research on this in recent years. Among them, the modified coating materials that have been studied more include hydroxyapatite film, diamond-like film, nitride film, silicon carbide film and polymer coating. From the perspective of coating materials, diamond-like films, nitride films, and silicon carbide films can significantly improve the corrosion resistance and wear resistance of the implanted material surface, and inhibit the precipitation of toxic ions, but these materials are biologically inert materials. There is no osteoinductive ability and osteoconductivity, and it cannot form osseointegration with bone tissue; the mechanical properties of polymer coating and bone tissue are similar, but the degradation and tissue inflammation problems in medical use cannot be avoided; hydroxyapatite film The layer has an excellent osteoinductive effect and can directly form an osseointegration with bone tissue, but hydroxyapatite is a brittle material with poor mechanical properties, and the formed film layer is not wear-resistant and has low bonding force. Compared with the above-mentioned materials, the hydroxyapatite film still has incomparable advantages. First of all, hydroxyapatite is the main component of biological hard tissue, and its mechanical properties are similar to those of bone tissue. Secondly, hydroxyapatite has excellent osteoinductive effect and can directly form osseointegration with bone tissue without other inflammatory reactions. Therefore, as long as the problem of poor mechanical properties of the hydroxyapatite material is solved, it will become an excellent coating for surface modification of medical metal materials.

In the research, it was found that the composite ceramic film layer formed by combining hydroxyapatite with Al ₂ O ₃ , TiO ₂ , ZrO ₂ and other oxides can greatly improve its mechanical properties and mechanical properties, and will not affect the excellent performance of hydroxyapatite itself. biological performance. It is worth mentioning that the plasma electrolytic oxidation technology developed in recent years has shown great advantages in the preparation of hydroxyapatite/oxide composite ceramic films. The ceramic film layer prepared by plasma electrolytic oxidation technology has high mechanical properties and is tightly combined with the substrate, which can achieve metallurgical bonding and high bonding force. Moreover, this film layer has a composite structure with a loose and porous outer layer and a compact and dense inner layer, which not only helps to improve the corrosion resistance of the matrix, but also effectively inhibits the precipitation of harmful ions in the matrix, and the loose and porous outer layer is tissue cells. It provides enough space for the climbing anchoring and growth proliferation, and it is an excellent modified coating.

However, when the plasma electrolytic oxidation technology is used to prepare the hydroxyapatite/oxide composite ceramic film layer, the medical metal material sample is in the anode position in the electrolytic cell, which makes the plasma electrolytic oxidation technology still have great limitations in its application. First, the plasma electrolytic oxidation technology is mainly used in valve metals such as titanium, zirconium, magnesium, and tantalum and their alloys, and its application in non-valve metals such as stainless steel, cobalt-chromium alloys, and nickel-chromium alloys is still very limited. Second, the plasma electrolytic oxidation technology will oxidize the matrix during operation, and the biotoxic ions in the matrix will be deposited in the newly formed oxide film, which will intensify the precipitation of toxic ions and reduce the biocompatibility of the material. Therefore, how to solve the two difficult problems of the traditional plasma electrolytic oxidation technology is a technical problem to be overcome.

Contents of the invention

The purpose of the present invention is to overcome the above-mentioned deficiencies of the prior art, to provide a method for preparing a hydroxyapatite oxide composite ceramic film layer on the surface of a medical metal implant material by cathodic plasma electrolytic deposition/hydrothermal treatment, to solve the existing problems. The technical problem that the matrix material is limited when the plasma electrolytic oxidation technology is used to prepare the hydroxyapatite/oxide composite ceramic film layer, the hydroxyapatite/oxide composite ceramic film layer prepared by this method has good mechanical properties at the same time It also has good biological stability and biological activity.

In order to realize the above-mentioned purpose of the invention, the technical scheme of the present invention is as follows:

A method for forming a composite ceramic film layer on the surface of a medical metal implant material, comprising the steps of:

The medical metal matrix material is used as the cathode, and the stainless steel electrolytic cell is used as the anode. In the electrolyte containing calcium, phosphorus and oxide precursors, a bidirectional pulse power supply is used to perform cathode plasma electrolytic deposition on the medical metal matrix material. Form an oxide ceramic film rich in calcium and phosphorus;

placing the medical metal implant material with the oxide ceramic film rich in calcium and phosphorus on its surface in a hydrothermal liquid for hydrothermal treatment, so that the oxide ceramic film rich in calcium and phosphorus forms hydroxyapatite Stone/oxide composite ceramic film layer.

And, a medical metal implant material, the surface of which is deposited with a hydroxyapatite/oxide composite ceramic film layer, and the hydroxyapatite/oxide composite ceramic film layer is composed of the medical metal implant material according to the present invention. It is prepared by the method of forming a composite ceramic film layer on the surface of the body material.

The method for forming a composite ceramic film layer on the surface of a medical metal implant material in the present invention first prepares an oxide ceramic film rich in calcium and phosphorus on the surface of a medical metal implant by means of cathode plasma electrolytic deposition technology; The calcium-phosphorus component of the compound is transformed into hydroxyapatite, forming a hydroxyapatite/oxide composite ceramic film layer. The method is simple, the equipment used is consistent with the traditional plasma electrolytic oxidation equipment, and the prepared film layer is firmly combined with the substrate, which can effectively improve the biological activity of the substrate material, inhibit the precipitation of harmful ions in the substrate material, and improve biocompatibility and safety. At the same time, it broadens the selection range of medical metal matrix materials.

The medical implant material of the present invention is prepared by forming a composite ceramic film layer on the surface of the medical metal implant material according to the present invention. Therefore, the hydroxyapatite/oxide composite ceramic film of the medical implant material of the present invention The bonding force between the layer and the medical metal matrix material is firm, its mechanical properties and mechanical properties are improved, and it has good biocompatibility with bone.

Description of drawings

The present invention will be further described below in conjunction with accompanying drawing and embodiment, in the accompanying drawing:

Fig. 1 is the electron microscope (SEM) scanning figure before the ceramic film hydrothermal is made on the surface of stainless steel by cathodic plasma electrolytic deposition in embodiment 1 of the present invention;

Fig. 2 is the scanning electron microscope (SEM) figure after the ceramic membrane hydrothermal of the embodiment 1 of the present invention is made on the surface of stainless steel;

Fig. 3 is the X-ray diffraction (XRD) figure after the hydrothermal containing ceramic film that embodiment 1 of the present invention makes on stainless steel surface;

Fig. 4 is the X-ray diffraction (XRD) figure of the zirconia-containing and hydroxyapatite ceramic membrane that the embodiment of the present invention 2 makes in NiTi alloy;

Fig. 5 is an electron microscope (SEM) scanning image of a ceramic film containing zirconia and hydroxyapatite prepared from a NiTi alloy in Example 3 of the present invention.

detailed description

In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention will be further described in detail below in conjunction with the embodiments and accompanying drawings. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

The embodiment of the present invention provides a method for forming a composite ceramic film layer on the surface of a medical metal implant material with a wide selection range of medical metal matrix materials and high biological activity, which includes the following steps:

Step S01: Using the medical metal base material as the cathode and the stainless steel electrolytic cell as the anode, in the electrolyte containing calcium, phosphorus and oxide precursors, use a bidirectional pulse power supply to perform cathode plasma electrolytic deposition on the medical metal base material , forming an oxide ceramic film rich in calcium and phosphorus on its surface;

Step S02: placing the medical metal implant material with the calcium-phosphorous-rich oxide ceramic film formed on the surface in a hydrothermal liquid for hydrothermal treatment, so that the calcium-phosphorus-rich oxide ceramic film is formed Hydroxyapatite/oxide composite ceramic film layer.

Specifically, in the cathode plasma electrodeposition system constructed in the above-mentioned step S01, the medical metal matrix material after surface treatment is used as the cathode, which can effectively broaden the selection range of medical metal matrix materials and avoid the existing plasma electrolytic oxidation. The limitations of technology on the selection of medical metal matrix materials can also effectively avoid the deposition of biotoxic ions in the matrix in the newly formed oxide film caused by the existing plasma electrolytic oxidation technology, which will aggravate the precipitation of toxic ions and reduce the biocompatibility of materials sex happens.

Therefore, in one embodiment, the medical metal base material can be valve metal or non-valve metal. It can be non-valve metals such as stainless steel, cobalt-chromium alloy, nickel-chromium alloy, etc.

During the cathodic plasma electrolytic deposition process in the above step S01, the quality of the deposited oxide ceramic film rich in calcium and phosphorus components can also be effectively controlled by controlling the electrolytic process conditions.

Therefore, in one embodiment, the process condition of the cathode plasma electrodeposition treatment is: the power output mode adopts the constant voltage mode, and the voltage is 280V-600V.

In another embodiment, the process conditions of the cathode plasma electrodeposition treatment are: the power output mode adopts the cross flow mode, and the current density is 0.01A/cm ² -5A/cm ² .

In a further embodiment, on the basis of the above-mentioned constant voltage mode or cross flow mode, the time of cathode plasma electrodeposition treatment is controlled to 10 min-120 min.

In this way, by controlling the above-mentioned cathode plasma electrolytic deposition current or voltage or further the electrolytic deposition time, the thickness, density and microcrystalline structure crystal form of the deposited and grown oxide ceramic film rich in calcium and phosphorus components can be effectively controlled, thereby Improve the density, mechanical strength and other properties of the oxide ceramic film rich in calcium and phosphorus, so that the quality of the oxide ceramic film rich in calcium and phosphorus is significantly improved.

In addition, by adjusting the composition of the electrolyte, the composition and performance of the oxide ceramic film rich in calcium and phosphorus components can be controlled. Therefore, in one embodiment, the electrolyte containing calcium phosphorus and oxide precursors contains the following components:

Phosphorus pentoxide 1-10g/L

Calcium nitrate 10-40g/L

Aluminum nitrate or zirconium nitrate 5-40g/L;

The solvent is ethanol or/and triethanolamine.

Through the above control of the electrolyte, the quality of the oxide ceramic film formed by electrolytic deposition is rich in calcium and phosphorus, and endows the oxide ceramic film with mechanical properties similar to bone tissue.

In a further embodiment, in step S01, the medical metal matrix material is subjected to surface treatment before the cathode plasma electrodeposition treatment, and the surface treatment is to remove oxide scales or pollutants, etc., so as to avoid oxidation of the metal matrix surface Effects of skin or pollutants on the quality of calcium-phosphorus-rich oxide ceramic films formed during cathodic plasma electrodeposition. In order to effectively remove oxide scales or pollutants on the surface of the medical metal base material, therefore, in one embodiment, the medical metal base material is polished and then cleaned. In a specific embodiment, SiC sandpaper may be directly used for polishing; and acetone, ethanol, and deionized water may be used for ultrasonic cleaning in sequence.

In the above step S02, the hydrothermal heat treatment of the oxide ceramic film rich in calcium and phosphorus components formed by deposition is to crystallize the oxide ceramic film rich in calcium and phosphorus components, so that the calcium and phosphorus components in the film layer are crystallized. Transformation into hydroxyapatite, so that the hydroxyapatite/oxide composite ceramic film layer.

Therefore, in one embodiment, the hydrothermal liquid is deionized water or an ammonia solution with a concentration of 0.1-1 mol/L. In a further embodiment, the process conditions of the hydrothermal treatment are: a pressure of 0.1-2 MPa, a temperature of 120-250° C., and 6-12 hours. By controlling the process conditions of hydrothermal treatment, the efficiency and quality of the crystallization of calcium and phosphorus components into hydroxyapatite can be improved, so that the hydroxyapatite/oxide composite ceramic film has a loose and porous outer layer and a compact inner layer. Composite structure, thereby effectively improving the quality of the hydroxyapatite/oxide composite ceramic film layer.

After the above steps S01 and S02 and the control of process conditions, in one embodiment, the thickness of the hydroxyapatite/oxide composite ceramic film layer deposited on the surface of the medical metal base material is 10-100 μm.

Therefore, the above-mentioned method for forming a composite ceramic film layer on the surface of a medical metal implant material prepares an oxide ceramic film rich in calcium and phosphorus on the surface of a medical metal implant by means of cathode plasma electrodeposition technology; The calcium and phosphorus components in the film layer are converted into hydroxyapatite to form a hydroxyapatite/oxide composite ceramic film layer. In addition, the method is simple, the equipment used is consistent with the traditional plasma electrolytic oxidation equipment, and the prepared film layer is firmly combined with the substrate, which can effectively improve the biological activity of the substrate material, inhibit the precipitation of harmful ions in the substrate material, and improve biocompatibility .

Correspondingly, on the basis of the above-mentioned method for forming a composite ceramic film layer on the surface of a medical metal implant material, an embodiment of the present invention also provides a medical implant material, the surface of which is deposited with Limestone/oxide composite ceramic film layer, the hydroxyapatite/oxide composite ceramic film layer is prepared by the above-mentioned method of forming a composite ceramic film layer on the surface of a medical metal implant material in the embodiment of the present invention . Therefore, the hydroxyapatite/oxide composite ceramic film layer of the medical implant material of the embodiment of the present invention has a strong bonding force with the medical metal matrix material, its mechanical properties and mechanical properties have been improved, and its biocompatibility with bone it is good.

In one embodiment, the thickness of the hydroxyapatite/oxide composite ceramic film layer is controlled to be 10-100 μm. By optimizing the thickness of the film layer, the mechanical properties and mechanical properties of the film layer can be further adjusted, and its biocompatibility with bone can be improved.

The above-mentioned method for forming a composite ceramic film layer on the surface of a medical metal implant material and the medical implant material prepared by the method are illustrated below through a plurality of examples.

Example 1

A method for forming a composite ceramic film layer on the surface of a medical metal implant material, comprising the steps of:

S11, the 1cm 316L stainless steel sample is ultrasonically cleaned by acetone, ethanol, and deionized water for ¹⁰ minutes;

S12, using a bidirectional pulse power supply, using a 316L stainless steel sample as the cathode, a stainless steel electrolytic cell as the anode, and using a solution containing phosphorus pentoxide (6g/L), calcium nitrate (20g/L), and aluminum nitrate (20g/L) as the The electrolyte is subjected to cathodic plasma electrolytic deposition treatment under stirring conditions; among them, the power supply mode adopts constant voltage mode, and the voltage is constant at 400V; the treatment time is 30min, and an alumina ceramic film rich in calcium and phosphorus is formed;

S13, the sample prepared with calcium and phosphorus-rich alumina ceramic membrane was subjected to hydrothermal treatment, the hydrothermal treatment was carried out in deionized water, the treatment temperature was 150°C, and the treatment time was 10h to form a hydroxyapatite/oxide composite ceramic membrane Floor.

The calcium-phosphorus-rich alumina ceramic film prepared in step S12 and the hydroxyapatite/oxide composite ceramic film layer produced in step S13 were subjected to scanning electron microscopy (SEM) analysis, and the results are shown in Figures 1 and 2, respectively. The hydroxyapatite/oxide composite ceramic film layer generated in step S13 was analyzed by X-ray diffraction (XRD), and the results are shown in FIG. 3 .

It can be seen from Figures 1 and 2 that the prepared film layer structure is uniform and has a porous structure on its surface. It can be seen from Figure 3 that hydroxyapatite (Ca ₁₀ (PO ₄ ) ₆ (OH) ₂ ), Katoite-type garnet (Ca ₃ Al ₂ ([OH] ₄ ) ₃ ) and soft water were obtained after hydrothermal treatment. Ceramic film of aluminum ore (AlO(OH)).

Example 2

S21, 1 cm ² nickel-titanium alloy is ultrasonically cleaned by acetone, ethanol, and deionized water for 10 minutes;

S22, use a bidirectional pulse power supply, use a nickel-titanium alloy sample as the cathode, and a stainless steel electrolytic cell as the anode, and use a solution containing phosphorus pentoxide (4g/L), calcium nitrate (15g/L), and zirconium nitrate (15g/L) It is an electrolyte, and the cathodic plasma electrolytic deposition process is carried out under stirring conditions; among them, the power supply mode adopts the constant voltage mode, and the voltage is constant at 480V; the processing time is 20min. Form a zirconia ceramic film rich in calcium and phosphorus;

S23, subjecting the sample prepared with the zirconia ceramic membrane rich in calcium and phosphorus to hydrothermal treatment. The hydrothermal treatment is carried out in deionized water at a treatment temperature of 150° C. for 8 hours to form a hydroxyapatite/oxide composite ceramic film.

The hydroxyapatite/oxide composite ceramic film layer generated in step S23 was analyzed by X-ray diffraction (XRD), and the results are shown in FIG. 4 . It can be seen from Figure 4 that the ceramic film containing hydroxyapatite and zirconia was obtained after hydrothermal treatment.

Example 3

S31, 1 cm ² nickel-titanium alloy is ultrasonically cleaned by acetone, ethanol, and deionized water for 10 minutes;

S31, using a bidirectional pulse power supply, using a nickel-titanium alloy sample as the cathode, and a stainless steel electrolytic cell as the anode, using a solution containing phosphorus pentoxide (7g/L), calcium nitrate (25g/L), and zirconium nitrate (25g/L) It is an electrolyte solution, and the cathodic plasma electrodeposition treatment is carried out under stirring conditions; wherein, the power supply mode adopts a constant current mode, and the current density is constant at 0.4A/cm ² ; the treatment time is 15 minutes. Form a zirconia ceramic film rich in calcium and phosphorus;

S33, subjecting the sample prepared with the calcium-phosphorus-rich zirconia ceramic film to hydrothermal treatment. The hydrothermal treatment was carried out in de-0.1M ammonia water, the treatment temperature was 150°C, and the treatment time was 10h, and finally a ceramic membrane containing hydroxyapatite and zirconia was obtained.

The hydroxyapatite/oxide composite ceramic film layer generated in step S33 was scanned and analyzed by electron microscope (SEM), and the results are shown in FIG. 5 . It can be seen from Fig. 5 that the hexagonal phase of hydroxyapatite has a hexagonal columnar structure.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. within range.

Claims (6)

1. A method for forming a composite ceramic film layer on the surface of a medical metal implant material, comprising the steps: The medical metal matrix material is used as the cathode, and the stainless steel electrolytic cell is used as the anode. In the electrolyte containing calcium, phosphorus and oxide precursors, a bidirectional pulse power supply is used to perform cathode plasma electrolytic deposition on the medical metal matrix material. An oxide ceramic film rich in calcium and phosphorus is formed. The cathode plasma electrolytic deposition treatment process conditions are: the power output mode adopts a constant voltage mode with a voltage of 280V-600V or a current density of 0.01A/cm ² -5A/cm ² constant current mode, the time is 10min-120min; placing the medical metal implant material with the oxide ceramic film rich in calcium and phosphorus on its surface in a hydrothermal liquid for hydrothermal treatment, so that the oxide ceramic film rich in calcium and phosphorus forms hydroxyapatite Stone/oxide composite ceramic film layer. 2. the method for forming composite ceramic membrane on the surface of medical metal implant material as claimed in claim 1, is characterized in that, the electrolyte containing calcium phosphorus and oxide precursor contains following components: Phosphorus pentoxide 1-10g/L Calcium nitrate 10-40g/L Aluminum nitrate or zirconium nitrate 5-40g/L The solvent is ethanol or/and triethanolamine. 3. The method for forming a composite ceramic film layer on the surface of a medical metal implant material as claimed in claim 1 or 2, wherein the hydrothermal liquid is deionized water or ammonia with a concentration of 0.1-1mol/L aqueous solution. 4. The method for forming a composite ceramic film layer on the surface of a medical metal implant material as claimed in claim 3, characterized in that: the process conditions of the hydrothermal treatment are: the pressure is 0.1-2MPa, and the temperature is 120-250°C , 6-12 hours. 5. The method for forming a composite ceramic film layer on the surface of a medical metal implant material according to any one of claims 1-2, 4, wherein the medical metal matrix material is valve metal or non-valve metal. 6. the method for forming composite ceramic film layer on the surface of medical metal implant material as claimed in claim 5, is characterized in that: described medical metal matrix material carries out surface treatment before carrying out cathodic plasma electrodeposition treatment, so The surface treatment includes the steps of polishing the surface first and then ultrasonic cleaning with acetone, ethanol and deionized water.