CN102605410A - Method for preparing bioactive composite film layer containing hydroxyapatite on titanium metal surface - Google Patents

Abstract

The invention provides a method for preparing a biologically active composite film layer containing hydroxyapatite on the surface of titanium metal. Firstly, an electrolytic solution containing hydroxyapatite is prepared, and then a voltage is applied to the titanium metal through a power supply to perform low-pressure deposition and micro-arc oxidation treatment. Low-voltage deposition stage: control voltage 30V-120V, deposition time 5-20min; micro-arc oxidation stage: control voltage 450V-600V, deposition time 10min, power supply frequency 200kHz, duty cycle 10%; After arc oxidation, a layer of HA-TiO ₂ composite ceramic layer can be grown on the surface of titanium metal sample. Its beneficial effect is that the ceramic layer containing HA particles is prepared in the electrolytic solution for the titanium metal sample, which simplifies the process of depositing HA particles on the surface of the titanium metal sample. By adjusting the content of HA in the electrolyte or the deposition voltage and time, the Change the content of HA in the film layer.

Description

Method for preparing bioactive composite film layer containing hydroxyapatite on the surface of titanium metal

technical field

The invention belongs to the technical field of surface treatment methods for titanium and titanium alloy implants, and relates to a method for preparing a titanium metal HA- _TiO2 composite film layer, specifically, depositing a hydroxyapatite-titanium dioxide composite film layer on the surface of titanium or titanium alloy , this film layer is a bioactive material, mainly used in medical fields such as artificial bones and teeth.

technical background

As biomedical materials, titanium and titanium alloys have excellent biocompatibility and mechanical properties, and are one of the commonly used human implant materials. However, implants have problems such as poor biological activity, low bonding strength, and severe corrosion in physiological environments, which limit their further clinical applications.

At present, the bioactivation of titanium metal surface is mainly realized by preparing bioactive coating and surface modification, and the bonding strength is improved by surface roughening.

As a typical biomedical material, hydroxyapatite (HA) has high biological activity and is easy to form a firm bond with bone tissue. Therefore, the preparation of titanium-based HA composite coating materials can make it have both high strength and high toughness of metal materials. , and has good biological activity. After implantation in the body, it forms a direct chemical bond with bone tissue, which is conducive to the early stability of the implant and shortens the postoperative healing period. It has become an important content in the research of biomedical materials.

Composite coating materials prepared by vacuum plasma spraying, laser deposition, electrophoretic deposition, ion-enhanced sputtering and other methods have their own shortcomings. In recent years, micro-arc oxidation technology has attracted much attention in the preparation of biological materials. The literature shows that the surface of titanium alloy treated by micro-arc oxidation can obtain a high-hardness ceramic layer with a rough and porous surface, a dense inner layer, and a metallurgical bond with the substrate. How to effectively introduce HA into the micro-arc oxidation ceramic layer has become a research hotspot and difficulty in recent years. In the literature, some people use micro-arc oxidation or anodic oxidation to prepare ceramic layers rich in calcium and phosphorus elements, and then induce the formation of bone-like apatite through constant temperature immersion in simulated liquid or hydrothermal synthesis treatment; while some people are After micro-arc oxidation pretreatment, a layer of HA/TiO ₂ composite film with a thickness of about 15-20 μm was prepared on the surface by electrophoretic deposition. Although the above method can be used to prepare a rough surface with certain biological activity, the preparation process is complicated, the HA content in the film layer is small, and the subsequent process will also cause a decrease in the binding force of the film base. Therefore, finding a simple process for depositing HA coating on the surface of titanium or titanium alloy is the key to the large-scale application of this technology.

Contents of the invention

The purpose of the present invention is to provide a method for preparing a bioactive composite film layer containing hydroxyapatite on the surface of titanium metal, which can directly prepare bonded or coated HA particles on the titanium surface while maintaining a good film-base bonding state ceramic layer.

The technical scheme adopted in the present invention is a method for preparing a bioactive composite film layer containing hydroxyapatite on the surface of titanium metal, and the specific operations are as follows:

Step 1, prepare the electrolytic solution

Mix calcium glycerine phosphate with a concentration of 3 to 5 g/L and calcium acetate with a concentration of 20 to 30 g/L to obtain a mixture A, and the solvent in the mixture A is distilled water; then add sodium hydroxide to the mixture A to adjust its The pH is 11 to obtain a mixture B; finally, hydroxyapatite is added to the mixture B in an amount of 3g/L-12g/L to obtain an electrolytic solution;

Step 2,

Put the titanium metal sample into the electrolytic solution prepared in step 1, connect the titanium metal sample to the positive electrode of the power supply, connect the negative electrode of the power supply to the stainless steel plate, and apply voltage to the titanium metal sample through the power supply to perform low-voltage deposition and micro-arc oxidation Processing, the corresponding relationship between power-on time and voltage is:

Low-voltage deposition stage: control voltage 30V ~ 120V, deposition time 5 ~ 20min;

Micro-arc oxidation stage: the control voltage is 450V-600V, the deposition time is 10min, the frequency of the power supply is 200kHz, and the duty cycle is 10%;

After low-pressure deposition and micro-arc oxidation, a layer of HA-TiO ₂ composite ceramic layer can be grown on the surface of titanium metal sample.

The beneficial effect of the present invention is that the ceramic layer containing HA particles is prepared from the titanium metal sample in the electrolytic solution, which greatly simplifies the process of depositing HA particles on the surface of the titanium metal sample. By adjusting the content of HA in the electrolyte or the deposition voltage and The content of HA in the film layer can be changed within a short time. This method is simple, and the prepared film layer has good adhesion, fully meets the medical requirements, and can solve the problem that this technology is difficult to apply on a large scale.

Description of drawings

Figure 1 is a schematic diagram of the structure of the micro-arc oxidation equipment for preparing a titanium metal HA- _TiO2 composite film layer. In the figure, 1. Electrolyzer, 2. Titanium metal sample, 3. Stainless steel cathode, 4. High voltage power supply system, 5. Control System, 6. Stirrer, 7. Cooling system;

Fig. 2 is the relationship diagram of the influence of low voltage deposition voltage on HA content in the ceramic layer;

Fig. 3 is the relationship diagram of the impact of deposition time on the HA content in the ceramic layer in the low-pressure deposition treatment stage;

Fig. 4 is the relation figure that micro-arc oxidation voltage influences HA content in the ceramic layer;

Fig. 5 is the relation figure that HA content in the electrolytic solution affects the HA content in the ceramic layer;

Figure 6 is a SEM photo of the surface morphology of the ceramic layer prepared in electrolyte solutions with different HA additions: Figure 6-(a) is a scanning photo of the surface of the ceramic layer prepared by adding quantitative HA particles at 3 g/L in the original electrolyte; Figure 6-(b) is a scanning photo of the surface of the ceramic layer prepared by adding quantitative HA particles at 6g/L in the original electrolyte; Figure 6-(c) is prepared by adding quantitative HA particles at 9g/L in the original electrolyte Scanning photo of the surface of the ceramic layer; Figure 6-(d) is a scanning photo of the surface of the ceramic layer prepared by adding quantitative HA particles at 12g/L in the original electrolyte;

Fig. 7 is the HA-TiO made through low-pressure deposition and micro-arc oxidation _The cross-sectional scanning photo of the composite ceramic layer;

Figure 8 is a photo of the surface morphology of the implanted nail after being implanted in the living animal for 3 months after being implanted into the animal body after surface treatment, wherein Figure 8-(a) is the implant made without adding HA during the low-pressure deposition process The photo of the implanted nail; Figure 8-(b) is a photo of the implanted nail made by adding HA during the low-pressure deposition process.

Detailed ways

The invention provides a method for preparing a bioactive composite film layer containing hydroxyapatite on the surface of titanium metal. The specific operations are as follows:

Step 1, prepare the electrolytic solution in the oxidation tank

Mix calcium glycerophosphate with a concentration of 3 to 5 g/L and calcium acetate with a concentration of 20 to 30 g/L to obtain a mixture A, and the solvent in the mixed solution A is distilled water; then add sodium hydroxide to the mixture A to adjust The pH is 11 to obtain a mixed solution B; finally, hydroxyapatite is added to the mixture B in an amount of 3 to 12 g/L to obtain an electrolyte solution;

Step 2,

Surface treatment of the titanium metal sample (titanium or titanium alloy) first: first polish the metal sample, and then clean and degrease it;

Then put the treated titanium metal sample into the electrolytic solution prepared in step 1, connect the titanium metal sample to the positive pole of the power supply, connect the negative pole of the power supply to the stainless steel plate, and apply voltage to the titanium metal sample through the power supply for low-voltage deposition With micro-arc oxidation treatment, the corresponding relationship between energization time and voltage is:

Low-voltage deposition stage: control voltage 30V ~ 120V, deposition time 5 ~ 20min;

Micro-arc oxidation stage: the control voltage is 450V-600V, the deposition time is 10min, the frequency of the power supply is 200kHz, and the duty cycle is 10%;

The above treatment of the titanium metal sample is carried out in the micro-arc oxidation equipment as shown in Figure 1. The electrolytic cell 1 is filled with the electrolytic solution, and the titanium metal sample 2 and the stainless steel cathode 3 are immersed in the electrolytic solution. The positive electrode of the power supply system 4 is connected to the titanium metal sample, the negative electrode is connected to the stainless steel plate cathode, the control system 5 controls the output voltage and time of the high-voltage power supply system 4, and the stirrer 6 is used to speed up the flow of the electrolyte to make the reaction more stable and cool down. System 7 is to cool down the electrolyte, because a lot of heat will be released during the micro-arc oxidation process.

After low-pressure deposition and micro-arc oxidation, a layer of HA-TiO ₂ composite ceramic layer can be grown on the surface of titanium metal sample.

Example 1

The method for preparing a biologically active composite film layer containing hydroxyapatite on the surface of titanium metal, the specific operations are as follows:

Step 1, prepare the electrolytic solution in the oxidation tank:

Mix the calcium glycerophosphate with a concentration of 4g/L and the calcium acetate with a concentration of 25g/L to obtain a mixture A, and the solvent in the mixed solution A is distilled water; then add sodium hydroxide to the mixture A to adjust its pH to 11 , to obtain a mixed solution B; finally add hydroxyapatite to the mixture B in an amount of 12g/L to obtain an electrolyte solution;

Step 2,

First surface treatment of pure titanium (purity 99.9%): first polished, then cleaned and degreased;

Then put the titanium metal sample into the electrolytic solution prepared in step 1, connect the titanium metal sample to the positive pole of the power supply, connect the stainless steel plate to the negative pole of the power supply, and apply a voltage to the titanium metal sample through the power supply for low-voltage deposition and deposition. For micro-arc oxidation treatment, the corresponding relationship between energization time and voltage is:

Low-voltage deposition stage: control voltage 120V, deposition time 20min;

Micro-arc oxidation stage: control voltage 600V, deposition time 10min, power frequency 200kHz, duty cycle 10%;

After low-pressure deposition and micro-arc oxidation, a layer of HA-TiO ₂ composite ceramic layer can be grown on the surface of titanium metal sample.

After testing, the HA content in the HA-TiO ₂ composite ceramic layer is 13.6%.

Example 2

The difference from Embodiment 1 is that only the control voltage of the low-voltage deposition stage is different, the voltage is 90V, and the rest are the same as Embodiment 1.

After testing, the HA content in the HA-TiO ₂ composite ceramic layer is 10.3%.

Example 3

The difference from Embodiment 1 is that only the control voltage of the low-voltage deposition stage is different, the voltage is 60V, and the rest are the same as Embodiment 1.

After testing, the HA content in the HA-TiO ₂ composite ceramic layer is 9.8%.

Example 4

The difference from Embodiment 1 is that only the control voltage of the low-voltage deposition stage is different, which is 30V, and the rest are the same as Embodiment 1.

After testing, the HA content in the HA-TiO ₂ composite ceramic layer is 9.2%.

From Example 1, Example 2, Example 3 and Example 4, it can be found that, as shown in Figure 2, under the same other conditions, as the low-pressure deposition process voltage changes from small to large, the HA in the ceramic layer The content also increases, and the increase is most obvious when the deposition voltage is 120V.

Example 5

The difference from Example 1 is that only the deposition time in the low-pressure deposition stage is different, and the deposition time is 15 minutes, and the rest are the same as in Example 1.

After testing, the HA content in the HA-TiO ₂ composite ceramic layer is 12.3%.

Example 6

The difference from Example 1 is that only the deposition time in the low-pressure deposition stage is different, and the deposition time is 10 min, and the rest are the same as in Example 1.

After testing, the HA content in the HA-TiO ₂ composite ceramic layer is 11.1%.

Example 7

The difference from Example 1 is that only the deposition time in the low-pressure deposition stage is different, and the deposition time is 5 minutes, and the rest are the same as in Example 1.

After testing, the HA content in the HA-TiO ₂ composite ceramic layer is 8.7%.

From Example 1, Example 5, Example 6 and Example 7, it can be found that, as shown in Figure 3, under the same situation of other conditions, as the deposition time of the low-pressure deposition process changes from small to large, the ceramic layer The content of HA also increased accordingly.

Example 8

The difference from Embodiment 1 is that only the control voltage of the micro-arc oxidation stage is different, and the voltage is 550V, and the rest are the same as Embodiment 1.

After testing, the HA content in the HA-TiO ₂ composite ceramic layer is 9.9%.

Example 9

The difference from Embodiment 1 is that only the control voltage of the micro-arc oxidation stage is different, and the voltage is 500V, and the rest are the same as Embodiment 1.

After testing, the HA content in the HA-TiO ₂ composite ceramic layer is 9.2%.

Example 10

The difference from Embodiment 1 is that only the control voltage of the micro-arc oxidation stage is different, and the voltage is 450V, and the rest are the same as Embodiment 1.

After testing, the HA content in the HA-TiO ₂ composite ceramic layer is 7.6%.

From Example 1, Example 8, Example 9 and Example 10, we can find that, as shown in Figure 4, under the same other conditions, the content of HA in the ceramic layer increases with the increase of the micro-arc oxidation voltage . It can be seen that the content of hydroxyapatite in the ceramic layer can be increased by increasing the voltage of micro-arc oxidation.

Example 11

The difference from Example 1 is that only the amount of hydroxyapatite added to the mixture B is different, and 9 g/L of hydroxyapatite is added to the original electrolyte, and the rest are the same as in Example 1.

After testing, the HA content in the HA-TiO ₂ composite ceramic layer is 10.4%.

Example 12

The difference from Example 1 is that only the concentration of hydroxyapatite added to the mixture B is different, and 6 g/L of hydroxyapatite is added to the original electrolyte, and the rest are the same as in Example 1.

After testing, the HA content in the HA-TiO ₂ composite ceramic layer is 9%.

Example 13

The difference from Example 1 is that only the concentration of hydroxyapatite is added to the mixture B, and 3 g/L of hydroxyapatite is added to the original electrolyte, and the rest are the same as in Example 1.

After testing, the HA content in the HA-TiO ₂ composite ceramic layer is 6.5%.

From Example 1, Example 11, Example 12 and Example 13, it can be found that, as shown in Figure 5, as the HA content in the electrolyte increases, the HA content in the ceramic layer also increases, indicating that in other Under the same conditions, the content of HA in the ceramic layer increases with the increase of the content of HA in the electrolytic solution. Therefore, the HA of the ceramic layer on the surface of the sample can be increased by increasing the HA content in the electrolytic solution, and the HA content in the electrolytic solution is proportional to the HA content in the final ceramic layer.

According to the scanned photo of the sample obtained in embodiment 1, embodiment 11, embodiment 12 and embodiment 13, Fig. 6 is obtained, which is the HA- _TiO composite film layer surface micro-morphology made by the electrolytic solutions of different HA contents SEM photos; Figure 6-(a): original electrolyte + 3gHA/L; Figure 6-(b): original electrolyte + 6gHA/L; Figure 6-(c): original electrolyte + 9gHA/L; Figure 6 -(d): original electrolyte + 12gHA/L; it can be seen from the figure that hydroxyapatite (HA) is distributed in the ceramic layer in the form of white particles. With the increase of HA content in the electrolyte, the white particles The number increases, and the diameter of the discharge micropores on the surface of the membrane layer increases accordingly. The increase of HA content and the increase of roughness are beneficial to the growth of biological tissue on it.

Example 14

The method for preparing a biologically active composite film layer containing hydroxyapatite on the surface of titanium metal, the specific operations are as follows:

Step 1, prepare the electrolytic solution in the oxidation tank:

Mix the calcium glycerophosphate with a concentration of 3g/L and the calcium acetate with a concentration of 20g/L to obtain a mixture A, and the solvent in the mixed solution A is distilled water; then add sodium hydroxide to the mixture A to adjust its pH to 11 , to obtain a mixed solution B; finally add hydroxyapatite to the mixed solution B in an amount of 3g/L to obtain an electrolytic solution;

Step 2,

First surface treatment of pure titanium (purity 99.9%): first polished, then cleaned and degreased;

Then put the titanium metal sample into the electrolytic solution prepared in step 1, connect the titanium metal sample to the positive pole of the power supply, connect the negative pole of the power supply to the stainless steel plate, and apply voltage to the titanium metal sample through the power supply for low-voltage deposition and micro-arc Oxidation treatment, the corresponding relationship between energization time and voltage is:

Low-voltage deposition stage: control voltage 30V, deposition time 5min;

Micro-arc oxidation stage: control voltage 450V, deposition time 10min, power frequency 200kHz, duty cycle 10%;

After low-pressure deposition and micro-arc oxidation, a layer of HA-TiO ₂ composite ceramic layer can be grown on the surface of titanium metal sample.

After testing, the HA content in the HA-TiO ₂ composite ceramic layer is 5.6%.

Example 15

The method for preparing a biologically active composite film layer containing hydroxyapatite on the surface of titanium metal, the specific operations are as follows:

Step 1, prepare the electrolytic solution in the oxidation tank:

Mix the calcium glycerophosphate with a concentration of 5g/L and the calcium acetate with a concentration of 30g/L to obtain a mixture A, and the solvent in the mixed solution A is distilled water; then add sodium hydroxide to the mixture A to adjust its pH to 11 , to obtain a mixed solution B; finally add hydroxyapatite to the mixed solution B in an amount of 12g/L to obtain an electrolytic solution;

Step 2,

Surface treatment of the titanium alloy (Ti-12Mo-6Zr-2Fe, model TMZF) is carried out: firstly, it is polished, and then it is cleaned and degreased;

Then put the titanium alloy into the electrolytic solution prepared in step 1, connect the titanium alloy sample to the positive electrode of the power supply, and connect the negative electrode of the power supply to the stainless steel plate, apply voltage to the titanium alloy through the power supply for low-voltage deposition and micro-arc oxidation treatment, and power on The relationship between time and voltage is:

Low-voltage deposition stage: control voltage 120V, deposition time 20min;

Micro-arc oxidation stage: control voltage 500V, deposition time 10min, power frequency 200kHz, duty cycle 10%;

After low-pressure deposition and micro-arc oxidation, a layer of HA-TiO ₂ composite ceramic layer can be grown on the surface of the titanium alloy sample.

After testing, the HA content in the HA-TiO ₂ composite ceramic layer is 6.2%.

As can be seen from Example 14 and Example 15, when the concentrations of calcium phosphate glycerol and calcium acetate in the electrolyte take the set concentration upper limit or lower limit respectively, the HA content of the prepared ceramic layer is higher than that of Example 1. The HA content in the obtained ceramic layer is low, indicating that the concentration of calcium phosphate glycerol and calcium acetate in the electrolyte cannot be taken too high or too low. In actual application, the concentration of calcium glycerophosphate is 4g/L, and the concentration of calcium acetate is 25g/L.

Referring to FIG. 7 , the sample obtained in Example 1 is subjected to cross-sectional morphology analysis, and the obtained scanning photo is obtained. It can be seen from the figure that the HA attached to the surface of the sample during the low-pressure deposition process was punctured by the high-voltage during the micro-arc oxidation process, causing the matrix micro-region to melt and sputter, and these molten substances solidified rapidly when they met the electrolyte. A part of HA deposited on the surface of the sample is coated in the solidification, exists in the film layer in the form of white clusters, or adheres to the surface of the ceramic layer.

Referring to Fig. 8, it is an implanted nail processed by the method of the present invention, which is a photo of the surface topography of the implanted nail after being implanted in the living animal body for 3 months and taken out, wherein Fig. 8-(a) is made by the electrolyte without adding HA Figure 8-(b) is a photo of implanted nails made by adding HA electrolyte. It can be seen that in Figure 8-(a), a part of the cell tissue with a certain thickness is formed on the surface of the implanted nail, and the micro-arc oxidation micropore is covered by a large number of cell tissue, but the micro-arc oxidation micropore can still be seen locally; However, in Figure 8-(b), the surface of the implanted nail is covered by a large number of cell tissues, and the existence of micropores is basically not visible on the surface. It shows that the micro-arc oxidation surface containing HA particles is beneficial to the growth of osteoblasts, and the combination is good. This is because the surface of the porous HA-TiO ₂ composite film is conducive to the attachment of osteoblasts and the growth of bone tissue, providing mechanical engagement force; and the existence of a certain amount of HA improves the combination of the implant and bone tissue, so that Titanium metal has good biocompatibility and bioactivity; at the same time, the HA particles coated and adhered to the interior and surface of the ceramic layer will not cause a decrease in the binding strength of the membrane matrix.

Claims (1)

1. The method for preparing a bioactive composite film layer containing hydroxyapatite on the surface of titanium metal is characterized in that the specific operations are as follows: Step 1, prepare the electrolytic solution Mix calcium glycerine phosphate with a concentration of 3 to 5 g/L and calcium acetate with a concentration of 20 to 30 g/L to obtain a mixture A, and the solvent in the mixture A is distilled water; then add sodium hydroxide to the mixture A to adjust its The pH is 11 to obtain a mixture B; finally, hydroxyapatite is added to the mixture B in an amount of 3g/L-12g/L to obtain an electrolytic solution; Step 2, Put the titanium metal sample into the electrolytic solution prepared in step 1, connect the titanium metal sample to the positive electrode of the power supply, connect the negative electrode of the power supply to the stainless steel plate, and apply voltage to the titanium metal sample through the power supply to perform low-voltage deposition and micro-arc oxidation Processing, the corresponding relationship between power-on time and voltage is: Low-voltage deposition stage: control voltage 30V ~ 120V, deposition time 5 ~ 20min; Micro-arc oxidation stage: the control voltage is 450V-600V, the deposition time is 10min, the frequency of the power supply is 200kHz, and the duty cycle is 10%; After low-pressure deposition and micro-arc oxidation, a layer of HA-TiO ₂ composite ceramic layer can be grown on the surface of titanium metal sample.

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