A polydopamine/casein phosphopeptides (PDA/CPP) bilayer was prepared on the pure titanium surface with macro and micro pits formed by sandblasting with large-grit and acid-etching (SLA). The PDA interlayer with extraordinary adhesion and the capability of second functional modification, linked CPP, the natural biomolecules, to the SLA titanium surfacevia covalent bonds. This two-step immersion modification process was simple and fea-sible. Field emission scanning electronic microscope (FESEM), energy dispersive spectroscope (EDS) and X-ray photoelectron spectroscppe (XPS) were utilized to analyze microtopography and elementary composition of PDA/CPP bilayer. Contact angle analysis, biomimetic mineralization examinations and human bone marrow stem cells (hBMSCs) experimentsin vitro were conducted to verify the biocompatibility of the modified surfaces. The results showed that the PDA/CPP bilayer was successfully grafted onto the SLA substrates through the two-step immersion method. The bilayer decreased the contact angle of SLA with pure water from 47.7° to 25.5°, showing the improved hydrophilicity obviously. Compact hydroxyapatite (HA) layer was formed after SLA/PDA/CPP im-mersed in simulated body fluid (SBF) for 1 d, demonstrating that the bilayer accelerated the rate of biomineraliza-tion significantly. Besides, the PDA/CPP bilayer efficiently enhanced the cell attachment, cell proliferation and cell mineralization.%在大颗粒喷砂酸蚀(SLA)工艺形成的三维多级嵌套孔洞结构纯钛表面,利用聚多巴胺(PDA)的超强粘附性和二次修饰功能,接枝生物大分子酪蛋白磷酸肽(CPP),制备PDA/CPP复合涂层.采用FESEM、EDS、XPS、水接触角分析仪、体外仿生矿化测试以及人骨髓间充质干细胞(hBMSCs)实验对样品表面进行表征分析和性能测试.结果表明,两步浸泡法成功在SLA表面制得PDA/CPP复合涂层.该涂层在保留SLA多孔形貌的同时,使水接触角从47.7°减小到25.5°,明显提高了SLA表面亲水性;在模拟体液浸泡1 d后的修饰表面即沉积了致密羟基磷灰石(HA),说明PDA/CPP显著加快了SLA表面生物矿化的速度.同时,SLA/PDA/CPP表面细胞粘附、增殖以及矿化活性都得到了明显改善.
展开▼
