Choudhary Saba, Haberstroh Karen M, Webster Thomas J
Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana, USA.
Tissue Eng. 2007 Jul;13(7):1421-30. doi: 10.1089/ten.2006.0376.
Vascular tissue possesses numerous nanostructured surface features, but most metallic vascular stents proposed to restore blood flow are smooth at the nanoscale. Thus, the objective of the present study was to determine in vitro vascular cell functions on nanostructured titanium (Ti) compared to conventional commercially pure (c.p.) Ti. Results of this study showed for the first time greater competitive adhesion of endothelial versus vascular smooth muscle cells on nanostructured Ti compared to conventional Ti after 4 hours. Moreover, when cultured separately, increased endothelial and vascular smooth muscle cell density was observed on nanostructured Ti compared to conventional c.p. Ti after 1, 3, and 5 days; endothelial cells formed confluent monolayers before vascular smooth muscle cells on nanostructured Ti. Results also showed greater total amounts of collagen and elastin synthesis by vascular cells when cultured on nanostructured Ti. Since a major mode of failure of conventional vascular stents is the overgrowth of smooth muscle cells compared to endothelial cells, these results suggest that while the functions of both types of vascular cells were promoted on nanostructured c.p. Ti, endothelial cell functions (of particular importance, cell density or confluence) were enhanced over that of vascular smooth muscle cells. Thus, the present in vitro study showed that vascular stents composed of nanometer c.p. Ti particles may invoke advantageous cellular responses for improved stent applications.
血管组织具有众多纳米结构的表面特征，但大多数用于恢复血流的金属血管支架在纳米尺度上是光滑的。因此，本研究的目的是确定与传统商业纯钛（c.p. Ti）相比，纳米结构钛（Ti）上的体外血管细胞功能。本研究结果首次表明，与传统Ti相比，4小时后内皮细胞与血管平滑肌细胞在纳米结构Ti上具有更强的竞争性黏附。此外，当分别培养时，与传统c.p. Ti相比，在1、3和5天后，纳米结构Ti上观察到内皮细胞和血管平滑肌细胞密度增加；在纳米结构Ti上，内皮细胞在血管平滑肌细胞之前形成汇合单层。结果还表明，当在纳米结构Ti上培养时，血管细胞合成的胶原蛋白和弹性蛋白总量更多。由于传统血管支架的主要失效模式之一是平滑肌细胞比内皮细胞过度生长，这些结果表明虽然两种类型的血管细胞功能在纳米结构c.p. Ti上均得到促进，但内皮细胞功能（特别重要的是细胞密度或汇合度）比血管平滑肌细胞功能增强。因此，本体外研究表明，由纳米c.p. Ti颗粒组成的血管支架可能引发有利的细胞反应，以改善支架应用。
