微/纳多级结构TiO_2涂层的制备及生物学性能

Fabrication and biological properties of micro/nano hybrid structured TiO_2 coatings

表面形貌是影响骨植入体稳定性的重要因素,仿生微/纳多级结构表面能加快早期细胞响应,加速植入体与骨组织间的整合,并改善其长期稳定性.以锐钛矿相二氧化钛悬浮液为喂料,采用液相感应等离子喷涂(induction suspension plasma spraying,ISPS)技术制备微/纳多级结构Ti02涂层,并对其细胞相容性进行了研究.扫描透射电子显微镜(scanning transmission electron microscopy,SEM)观察结果表明,通过对进料速率的调控,可制备典型微/纳多级结构的Ti02涂层,气孔率随进料速率的增大而增大.X射线衍射(X-ray diffraction,XRD)结果表明,涂层以金红石相为主,并含少量锐钛矿相,金红石相含量随进料速率的增大而降低,这可能与等离子体喷涂的高温过程有关,锐钛矿相二氧化钛在此过程中发生相变,产生了更为稳定的金红石相.通过体外细胞相容性检测发现,ISPS制备的微/纳多级结构TiO_2涂层具有较高的蛋白吸附水平,成骨细胞在其表面能较好铺展,碱性磷酸酶(alkaline phosphatase,ALP)活性、矿化等基因表达均高于大气等离子喷涂涂层和光滑钛表面.

Micro/nano hybrid structured surface can improve their capability of encourag- ing early cell responses and rapid bone in-growth. The micro/nano hybrid structured TiO2 coatings were prepared by induction suspension plasma spraying （ISPS） using anatase TiO2 suspension as a feedstock. Their osteogenesis related cell behaviors were studied. Scanning transmission electron microscopy （SEM） results show that the coatings prepared by adjusting feed rate have typical micro/nano hybrid structures. Porosity of the coating increases with the increase of feed rate. The X-ray diffraction （XRD） results show that the coating is mainly composed of futile with a small amount of anatase, and the content ot rutlle decreased with the increase of feed rate. This may be related to the high temperature process of plasma spraying, in which the anatase phase is transformed into a more stable rutile phase. The results of in vitro cell compatibility tests show that the micro/nano structured TiO2 coatings prepared with ISPS has higher protein adsorption, better osteoblasts spreading and higher expression of alkaline phosphatase （ALP） activity and mineralization than atmospheric plasma sprayed coatings and polished titanium surfaces.