紫外光照射纳米钛表面生物抗老化的体外研究

目的：研究紫外光照射对老化TiO2纳米管表面理化性质和生物活性的影响。方法两步阳极氧化后的钛片避光保存8周，使其充分老化，紫外光照射48 h；利用场发射扫描电镜(FESEM)、X射线光电子能谱(XPS)、接触角测量仪分析新鲜、老化及紫外光照射组钛片表面微观结构、化学元素和接触角变化；以小鼠骨髓未分化间充质干细胞( MSCs)为细胞株，检测各组钛表面对细胞黏附、增殖及分化的影响，评价各组间生物学差异。结果 FESEM显示紫外光照射未改变钛表面TiO2纳米管形态， XPS结果显示老化组表面C元素含量显著增高，经紫外光照射后恢复到新鲜组水平，接触角检测显示老化组表面呈疏水性，紫外光照射组表面成超亲水性。体外细胞学实验显示，紫外光照射后钛表面有利于细胞黏附、增殖和分化。结论紫外光照射可去除钛表面碳氢化合物污染，提高表面亲水性，延缓时间因素造成的TiO2纳米管表面的生物活性降低。

The study of biological aging resistance of nano titanium surface treated with UV irradiation in vitro

Objective To study the impact of UV radiation on the physicochemical properties and biological activity of aging TiO2 nanotube surface. Methods Titanium plates treated by two-step anodization were stored in dark for eight weeks, sufficient to aging, and irradiated by UV for 48 h. Field emission scanning electron microscopy ( FESEM) , X-ray photoelectron spectroscopy ( XPS) and contact angle measurement were used to analyze the mi-crostructure, chemical elements and the contact angle of the surface of the fresh, aging, UV irradiation groups, re-spectively. Mouse bone marrow mesenchymal stem cells (MSCs) as cell lines were cultured on the treated titanium plates to determine the effect of modified titanium surface on the cell adhesion, proliferation and differentiation, fur-ther to evaluate biological differences among the three groups. Results FESEM displayed UV irradiation did not change the morphology of TiO2 nanotubes on the titanium surface. XPS showed that C elements on the surface of ag-ing group significantly increased after UV irradiation but restored to the level of fresh group by UV irritation. The contact angle analysis showed that the surface of age group was hydrophobic while the surface of UV irradiated group was superhydrophilic. In vitro cell culture showed that UV irritation was conducive to cell adhesion, proliferation and differentiation. Conclusion UV radiation can remove hydrocarbon contamination on surface of titanium, im-prove the surface hydrophilicity, and delay the bioactive decrease of titanium-based TiO2 nanotube surface by time factors.