Objective: To develope a titanium specimen with good osteogenic activity through fabrication of a composite hydroxyapatite coating on ordered micro-/nanotextured titanium surface. Methods: An ordered micro-/nanotextured structure was prepared on the surface of titanium (the control), and then hydroxyapatite was deposited on the as-prepared ordered micro-/nanotextured structure by alternative loop immersion method. The ordered micro-/nanotextured structures before and after hydroxyapatite deposition were denoted as HA and MN, respectively. Surface morphology was observed using a scanning electron microscope. Bone marrow mesenchymal stem cells (BMMSC) were seeded on the surface of three different materials. Cell morphology was observed with a scanning electron microscope. Cell adhesion and cell proliferation were evaluated using 4', 6-diamidino-2-phenylindole staining and cell counting kit-8 assay, respectively. Extracellular matrix mineralization and the expression levels of osteogenesis-related genes were evaluated by alizarin red staining and real-time quantitative PCR, respectively. Each group has three samples in every experiment. Results: After alternative loop immersing, the MN's original microholes (20 μm in diameter) were retained, and the uniform petal-like hydroxyapatite was deposited on the MN's original titania nanotubes (70 nm in diameter). Compared with the control, BMMSC on MN and HA elongated further and intersected along the micron structure with noticeable pseudopodia and pseudoplates, and the trend was more pronounced especially on HA. The number of early adherent cells on HA was remarkably larger than that on the control and MN at each time point (P<0.05). On day 1, the A value of cell proliferation on HA was significantly higher than that on the control and MN (P<0.05). The A value of cell proliferation on HA was significantly lower than that on the control and MN on day 3 (P<0.05). On day 7, the A value of cell proliferation on HA was significantly lower than that on MN (P<0.05), but there was no statistically significant difference in the A value of cell proliferation between HA and the control on day 7 (P>0.05). The Avalue of extracellular matrix mineralization on HA (0.607±0.011) was significantly higher than that on the control and MN (0.268±0.025 and 0.522±0.022, respectively) (t=-0.25, P<0.001; t=-0.34, P<0.001). The expression levels of bone related genes on HA were significantly higher than those on the control and MN (P<0.05). Conclusions: HA could promote the BMMSC adhesion and osteogenic differentiation, support BMMSC proliferation, and demonstrate good osteogenic activity.
目的： 探讨钛表面构筑的有序微纳米分级结构复合羟基磷灰石涂层对骨髓间充质干细胞（BMMSC）黏附、增殖及成骨分化的影响，以期构筑出具有良好成骨活性的钛试样。 方法： 在纯钛试样（对照组）表面制备有序微纳米分级结构（MN组），通过交替循环浸泡法在MN组钛试样表面进一步沉积羟基磷灰石（HA组），扫描电镜观察3组钛试样的表面形貌。将BMMSC接种至3组钛试样表面，4′，6-二脒基-2-苯基吲哚染色法检测0.5、1.0、2.0 h后细胞黏附情况，扫描电镜观察2 d后细胞黏附形态，细胞计数试剂盒法检测1、3、7 d时细胞增殖情况，茜素红染色法和实时荧光定量PCR分别检测14 d后细胞外基质矿化和成骨相关基因表达情况，每组每项实验各3个试样。 结果： HA组钛试样保留了MN组钛试样原有的20 μm孔径的微米凹坑阵列，且原有的70 nm管径的二氧化钛纳米管上出现均匀的花瓣样羟基磷灰石沉积。与对照组相比，MN组和HA组BMMSC顺着微米结构充分铺展和交汇，并伸出较多伪足和伪板，HA组试样表面这种趋势表现得更明显。HA组各时间点早期细胞黏附数量均显著大于对照组和MN组（P<0.05）。1 d时HA组细胞增殖A值显著大于对照组和MN组（P<0.05）；3 d时HA组细胞增殖A值显著小于纯钛组和MN组（P<0.05）；7 d时HA组细胞增殖A值显著小于MN组（P<0.05），但与对照组差异无统计学意义（P>0.05）。HA组细胞外基质矿化检测A值（0.607±0.011）显著大于对照组和MN组（分别为0.268±0.025和0.522±0.022）（t=-0.25，P<0.001；t=-0.34，P<0.001）。HA组成骨相关基因表达水平均显著高于对照组和MN组（P<0.05）。 结论： 钛表面构筑的有序微纳米分级结构复合羟基磷灰石涂层可促进BMMSC的细胞黏附和成骨分化，并支持BMMSC细胞增殖，具有良好的成骨活性。.