SiO_2含量对激光熔覆含La_2O_3生物陶瓷涂层性能的影响

采用激光熔覆技术,利用CaHPO_4·2H_2O,CaCO_3,La_2O_3,SiO_2粉末和Ti粉在医用钛合金Ti-6Al-4V表面制备掺杂的质量分数分别为0%,5%,10%,15%SiO2的含La2O3梯度生物陶瓷涂层,并研究了SiO_2含量对涂层性能的影响。利用金相显微镜、扫描电镜、能谱仪、X射线分析仪分别对涂层进行显微结构、表面元素、物相组成分析,利用MTT细胞活性检测法对涂层上种植的小鼠破骨前体细胞(RAW264.7)进行细胞活性分析。结果显示:掺杂10%~15%的SiO_2后,涂层的裂纹明显减少,且厚度变均匀。涂层在模拟体液(SBF)中浸泡2周后,羟基磷灰石(HA)在掺杂10%SiO_2涂层表面的沉积量最多,涂层表面的金属元素含量稀少,这表明含10%SiO_2涂层在SBF中具备更加优良的沉积HA的能力,同时有效的阻碍了基体中重金属离子的析出。MTT结果表明,掺杂SiO_2的涂层对破骨前体细胞的活性有更加明显的抑制作用。

Effects of SiO2 Content on Properties of La2O3-containing Bioceramic Coating Fabricated by Laser Cladding

Bioceramic coating with La₂O₃ was fabricated on the surface of medical titanium alloy Ti-6Al-4V by laser cladding. Cladding materials were pure CaHPO₄·2H₂O, CaCO₃, La₂O₃, SiO₂ and Ti powders. The doping amount of SiO₂ within the coating was 0%, 5%, 10% and 15%, respectively. The effect of SiO₂ concent on properties of the bioceramic coating with La₂O₃ was studied. The microstructure, surface elements and phases of the coating were characterized by OM, SEM, EDS and XRD. MTT assay was used to study the activity of mouse osteoclast precursor cells (RAW264.7) which were seeded on the coating. The results show that the number of cracks decreases obviously and the thickness of coating become uniform when the doping amount of SiO₂ varies from 10% to 15%. After soaking in SBF for two weeks, the amount of hydroxyapatite (HA) on the coating with 10% SiO₂ is higher than that of other coatings and the content of metal element on coating is few, which indicates that the coating doped 10% SiO₂ is of the best ablity to form HA in SBF, meanwhile, the release of metal ions is inhibited effectively. The MTT results show that the activity of osteoclast precursor cells is significantly inhibited by the coating doped SiO₂.