Department of Mechanical and Industrial Engineering, Ryerson University, 350 Victoria Street, Toronto, ON M5B 2K3, Canada.
Acta Biomater. 2011 Jun;7(6):2726-32. doi: 10.1016/j.actbio.2011.02.020. Epub 2011 Feb 25.
The primary objective of current tissue regeneration research is to synthesize nano-based platforms that can induce guided, controlled, and rapid healing. Titanium nanotubes have been extensively considered as a new biomaterial for biosensors, implants, cell growth, tissue engineering, and drug delivery systems. However, due to their one-dimensional structure and chemical inertness, cell adhesion to nanotubes is poor. Therefore, further surface modification is required to enhance nanotube-cell interaction. Although there have been a considerable number of studies on growing titanium nanotubes, synthesizing a three-dimensional (3-D) nano-architecture which can act as a growth support platform for bone and stem cells has not been reported so far. Therefore, we present a novel technique to synthesize and grow 3-D titania interwoven nanofibrous structures on a titanium substrate using femtosecond laser irradiation under ambient conditions. This surface architecture incorporate the functions of 3-D nano-scaled topography and modified chemical properties to improve osseointegration while at the same time leaving space to deliver other functional agents. The results indicate that laser pulse repetition can control the density and pore size of engineered nanofibrous structures. In vitro experiments reveal that the titania nanofibrous architecture possesses excellent bioactivity and can induce rapid, uniform, and controllable bone-like apatite precipitation once immersed in simulated body fluid (SBF). This approach to synthesizing 3-D titania nanofibrous structures suggests considerable promise for the promotion of Ti interfacial properties to develop new functional biomaterials for various biomedical applications.
当前组织再生研究的主要目标是合成纳米级平台，以诱导、控制和加速愈合。钛纳米管已被广泛认为是生物传感器、植入物、细胞生长、组织工程和药物输送系统的新型生物材料。然而，由于其一维结构和化学惰性，细胞与纳米管的黏附性较差。因此，需要进一步的表面修饰来增强纳米管与细胞的相互作用。尽管已经有相当多的关于生长钛纳米管的研究，但到目前为止，还没有报道合成一种可以作为骨和干细胞生长支撑平台的三维（3-D）纳米结构。因此，我们提出了一种新的技术，即在环境条件下使用飞秒激光辐照在钛基底上合成和生长三维钛互连纳米纤维结构。这种表面结构结合了三维纳米尺度形貌和改性化学性质的功能，以提高骨整合能力，同时为其他功能剂提供空间。结果表明，激光脉冲重复频率可以控制工程化纳米纤维结构的密度和孔径。体外实验表明，钛纳米纤维结构具有优异的生物活性，一旦浸入模拟体液（SBF）中，就能迅速、均匀且可控地诱导形成类似骨的磷灰石沉淀。这种合成三维钛纳米纤维结构的方法为促进 Ti 界面性能提供了很大的潜力，以开发用于各种生物医学应用的新型功能性生物材料。
