通过聚多巴胺自组装在钛表面构建钙离子螯合平台,探讨聚多巴胺的酚羟基(–C–OH)和醌基(–C=O)螯合钙离子机理,并研究其生物学性能。利用X射线光电子能谱分析聚多巴胺螯合钙离子化学基团的变化,结果显示:聚多巴胺螯合钙离子后,–C–OH峰面积从73.8%降至37.3%,–C=O从26.2%升至62.7%,证明聚多巴胺的酚羟基与钙离子螯合过程中向醌基转化;场发射扫描电镜、傅立叶红外光谱、X射线衍射仪和透射电镜分析表明聚多巴胺和钙离子的协同作用促进羟基磷灰石(HA)前驱体成核,诱导HA的形成;采用小鼠成骨细胞(MC3T3-E1)粘附和活性实验进行细胞相容性评价,结果表明钛表面通过聚多巴胺螯合低浓度的钙离子有利于成骨细胞粘附,且具有良好的细胞相容性。
Calcium ions chelation platform was successfully obtained on a titanium surface by modification with polydopamine. The chelation mechanism of polydopamine with Ca^2+ was studied. The in vitro bioactivity and cytocompatibility of Ca^2+ chelation platform was assessed by incubation in simulated body fluids(SBF) and cultural osteoblast cells(MC3T3-E1), respectively. The results showed that the functional groups of polydopamine chelated Ca^2+ were changed from phenolic hydroxyl to benzoquinone. The titanium surface modified by Ca^2+-chelated polydopamine could induce nucleation and growth of hydroxyapatite in SBF. Meanwhile, Cell attachment and viability assay demonstrated that low concentration of Ca^2+ chelation possessed good cytocompatibility.