微弧氧化方法在钛表面注入钙磷离子及对成骨细胞早期附着的影响

Modification of titanium surface with calcium and phosphorus ions using micro-arc oxidation and its effect on osteoblast attachment

目的探讨采用微弧氧化技术在钛表面注入钙、磷离子进行表面改性及其对成骨细胞早期附着和铺展的影响.方法在含有钙、磷离子的电解液中对钛试件进行微弧氧化处理,通过X射线能谱分析测试电解液中的Ca2+、PO43-浓度及电压、占空比、频率等电参数对形成的表面陶瓷膜中钙、磷离子含量的影响,扫描电镜观察陶瓷膜表面形貌,通过剪切粘结试验测试陶瓷膜与钛基体的结合力.将成骨样细胞MC-3T3-E1接种于试件表面进行培养来观察陶瓷膜对细胞附着的影响.结果微弧氧化处理在钛试件表面形成了一层TiO2陶瓷膜,表面均匀分布着2～10μm的微孔,陶瓷膜内含有钙、磷成分且钙、磷含量和电解液中的Ca2+、PO43-浓度成正比,随着电压、占空比的升高而增加,随着频率的升高而减少.TiO2陶瓷膜与钛基体的平均结合力为22±3 MPa.陶瓷膜促进了成骨细胞在其表面早期大量附着并形成良好的细胞形态.结论微弧氧化处理可在钛表面获得了一层与基体结合紧密、表面粗糙多孔、含有Ca2+、PO43-离子的TiO2陶瓷膜,并可通过电参数及电解液配方调整来控制钙、磷的含量,提高了钛的生物相容性.

Objective To study the method for modifying titanium surface with calcium and phosphorus ions using micro-arc oxidation technique and observe osteoblast attachment to the modified surface. Methods TA2 titanium discs were treated with micro-arc oxidation in electrolyte solution containing Ca2+ and PO43-. The influence of Ca2+ and PO43- concentrations in the solution and the electrical parameters of the micro-arc oxidization on the content of calcium and phosphorus ions incorporated into the surface of titanium was investigated using energy-dispersive X-ray (EDX) analysis. Scanning electron microscopy was employed for morphological observation of the ceramic coating on the metal surface. The binding strength of ceramic coating with titanium was tested by shear bonding experiment. MC-3T3-E1 osteoblast-like cells were then cultured on the treated surface of titanium discs to investigate the influence of the ceramic coating on osteoblast attachment. Results Micro-arc oxidation treatment produced a layer of porous TiO2 coating on the surface of titanium discs, with the average pore size of 2 to 10 μm. EDX analysis revealed that the ceramic coating contained Ca and P elements, whose content had close correlation with Ca2+ and PO43- concentrations in the electrolyte solution and voltage, duty cycle and frequency of micro-arc oxidation. The average bonding strength of the ceramic coating with titanium was 22±3 MPa, and TiO2 coating promoted attachment and spread of osteoblast-like cells on the metal surface as demonstrated by cell culture. Conclusions Porous TiO2 coating can be constructed on the surface of titanium using micro-arc oxidation, and Ca2+ and PO43- incorporated into the coating can improve the biocompatibility of titanium. The content of Ca2+ and PO43- in the coating can be modulated by adjusting the concentrations of Ca2+ and PO43- in the electrolyte solution and the electrical parameters of the micro-arc oxidation.