真空冷喷涂制备生物功能化纳米金刚石/羟基磷灰石复合涂层研究

Coating deposition of biomedical materials on titanium surfaces is the key to solve the problems pertain to insufficient osseointegration of the titanium alloys for clinical surgery. The research efforts made by biomaterials community have therefore been devoted to synthesis of and coating fabrication techniques for novel biomaterials with both sufficient mechanical strength and favorable biocompability. In this project, novel hydroxyapatite/nanodiamond-bone morphogenetic proteins 2-chitosan (HA/ND-BMP2-CS) composite powder is developed. The dynamic synthesis process of the powder is to be in situ monitored using NanoSight system. The vacuum cold spray technique is employed for the coating deposition of the HA/ND-BMP2-CS at room-temperature . Microstructural characterization and assessment of mechanical/biological properties of the coatings are conducted. Based on this project, clarification of the formation mechanism of the novel HA/ND-BMP2-CS biomedical coatings is anticipated. The relationships among processing, microstructure and properties are to be disclosed and high loading rate of BMP2 in the nanocomposite coatings is achieved. These results together with biological performances of the coatings as evaluated by cell culture testing would give fundamental insights into developing novel promising nanocomposites for biomedical applications.

医用钛材表面生物涂层技术是解决钛植入体与组织间不良骨整合的关键，而兼备强力学和骨诱导性能的新型生物材料及其涂层技术开发是目前的研究重点，相关研究具有重大的基础和临床应用价值。本项目拟合成羟基磷灰石（HA）/纳米金刚石-骨形态发生蛋白2-壳聚糖新型复合粉末，采用NanoSight系统的纳米颗粒追踪技术实时动态监测复合粉末合成过程，并利用真空冷喷涂技术室温下制备生物功能化纳米金刚石/HA复合生物涂层，开展涂层微观结构表征和力学性能及骨细胞行为研究。基于本项目研究，揭示生物功能化纳米金刚石/HA粉末及其真空冷喷涂生物复合涂层的形成机制，建立生物功能化纳米金刚石/HA涂层结构特征与涂层性能之间的关系体系，实现骨诱导因子在涂层中的高负载和生物活性，明确金刚石/HA纳米复合涂层对骨细胞的粘附、分化等生物学行为的调控行为，为开发具有自主知识产权的新型医用钛材-生物涂层骨修复植入体提供基础数据。

钛材植入体与组织间不良骨整合易导致植入体固定强度不足，造成植入体松动并引发植入失败。而我国钛基骨植入医疗器械的基础研究相对薄弱，目前我国临床使用的骨植入体/装置大部分依赖于从国外进口，相关研究具有重大的临床应用意义。本项目以医用钛合金为基体，采用真空冷喷涂系统，通过调整真空冷喷涂过程中的气流量、喷涂距离以及喷枪行走速度等工艺参数完成生物功能化纳米金刚石/HA复合涂层的制备。成功的制备了生物功能化纳米金刚石/HA复合生物涂层；初步揭示了新型生物功能化纳米金刚石/HA复合粉末及真空冷喷涂涂层的形成机制；建立了生物功能化纳米金刚石/HA复合涂层结构特征与涂层典型性能之间的关系；实现了药物或生物活性因子的高负载。通过激光共聚焦显微镜定性、定量分析了细胞的形态和铺展状态；利用扫描电镜研究了细胞在钛材界面的生长状态和伪足等表达状态，结果表明生物功能化纳米金刚石/HA复合涂层促进了该功能性钛材表面对骨细胞的粘附、增殖等生物学行为的调控；相关研究结果为开发具有自主知识产权的新型医用钛材-生物涂层骨修复植入体提供基础数据。