中文摘要：

目的：为改善纯钛的生物活性，对其表面进行梯度氧化钛生物活性涂层修饰，观察前成骨细胞MC3T3-E1在梯度氧化钛涂层修饰的钛上的黏附、增殖、形态和分化，评价该梯度涂层的生物活性。 方法：实验于2006—03／12在清华大学生物膜与膜生物工程国家重点实验室完成。①梯度涂层的制备：先用阳极氧化的方法在纯钛上制备一层致密的氧化钛膜，而后在该致密膜上用微弧氧化法生成一层多孔的氧化钛膜。②细胞接种：将前成骨细胞MC3T3．E1接种到梯度涂层修饰的钛试件上（梯度改性试件），未修饰的钛和只有一层氧化钛修饰的钛试件也同样接种细胞作为参照。③观察指标：接种3h和6h后用MTT的方法检测细胞的黏附情况；培养3d后用扫描电镜观察细胞的生长形态；分别在培养7，14和21d后用M1_r的方法分析MC3T3-E1细胞的增殖情况；将接种细胞的3种试件放于诱导培养基中，诱导培养28d后通过检测碱性磷酸酶的活性来分析细胞向成骨细胞的分化情况。 结果：①接种3h后．在未修饰的钛和氧化改性试件上黏附的细胞数相近．比在梯度改性试件上的黏附细胞数要少；6h后在梯度改性试件上的细胞数的增加更显著，是未修饰的钛上细胞数的1．5倍。②培养3d后扫描电镜观察到细胞在所有材料上都能够正常生长，细胞在3种材料上的形态比较相似，都表现出正常MC3T3-E1细胞的形态。⑧MC3T3-E1细胞在所有试件上都随时问而有所增殖。在梯度改性试件上的细胞数最高，未修饰的钛上的细胞数最少，在7d的差别不是很明显．而第21天时梯度改性试件上的细胞数是纯钛上细胞数的4倍。④在诱导培养基中培养28d后，在梯度改性试件上培养的MC3T3-E1细胞的碱性磷酸酶活性是最高的，是纯钛试件的2倍。 结论：MC3T3-E1细胞在梯度改性试件上的黏附、增殖和分化都是3种试?

英文摘要：

AIM： To assess the bioactivity of titanium modified with gradient TiO2 coating by the study of the attachment, proliferation, morphology and differentiation of preosteoblast MC3T3-E1 cell cultured on it. METHODS： The experiments ware completed in the State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua University from March to December in 2006. ①The titanium was selected as substrate and a structural gradient TiO2 coating was produced by hybrid oxidation techniques. A dense oxide film as the inner layer was produced by anodic oxidation and a porous oxide film as the outer layer was produced by micro-arc oxidation. ②The preosteoblast MC3T3-E1 cells ware cultured on the titanium modified with the gradient coating. The untreated titanium and titanium coated with only an oxide film were used as controls. ~After 3 and 6 hours of seeding, the attachment of MC3T3-E1 cells was determined by methyl thiazolyl tetrazolium （MTT） assay. After 3 days of culture, the morphology of cell growing on all specimens was observed by scanning electron microscope. After cell culturing for 7, 14 and 21 days, the proliferation of MC3T3-E1 cells was determined by MTT assay. The MC3T3-E1 cells on three specimens ware cultured in inducing culture medium. After 28 days, the alkaline phosphatase （ALP） activity of cells cultured on all specimens was evaluated to assess the differentiation of cells to osteoblasts. RESULTS： ①After 3 hours of seeding, MC3T3-E1 cells had attached to all the specimens, while those controls were less attached. And there were more cells attached on the gradient coating after 6 hours of seeding, which was 1.5 times of the value for untreated titanium. ②After 3 days of culture, the MC3T3-E1 cells grew wall on the surface of all the specimens. Morphology of the cells on all the specimens was identical to be characteristics of normal MC3T3-E1 cells.③ The number of cells on all the specimens increased with time. The cells of gradient coating ware the most among all the specim