Choudhary Saba, Berhe Mikal, Haberstroh Karen M, Webster Thomas J
Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA.
Int J Nanomedicine. 2006;1(1):41-9. doi: 10.2147/nano.2006.1.1.41.
In the body, vascular cells continuously interact with tissues that possess nanostructured surface features due to the presence of proteins (such as collagen and elastin) embedded in the vascular wall. Despite this fact, vascular stents intended to restore blood flow do not have nanoscale surface features but rather are smooth at the nanoscale. As the first step towards creating the next generation of vascular stent materials, the objective of this in vitro study was to investigate vascular cell (specifically, endothelial, and vascular smooth muscle cell) adhesion on nanostructured compared with conventional commercially pure (cp) Ti and CoCrMo. Nanostructured cp Ti and CoCrMo compacts were created by separately utilizing either constituent cp Ti or CoCrMo nanoparticles as opposed to conventional micron-sized particles. Results of this study showed for the first time increased endothelial and vascular smooth muscle cell adhesion on nanostructured compared with conventional cp Ti and CoCrMo after 4 hours' adhesion. Moreover, compared with their respective conventional counterparts, the ratio of endothelial to vascular smooth muscle cells increased on nanostructured cp Ti and CoCrMo. In addition, endothelial and vascular smooth muscle cells had a better spread morphology on the nanostructured metals compared with conventional metals. Overall, vascular cell adhesion was better on CoCrMo than on cp Ti. Results of surface characterization studies demonstrated similar chemistry but significantly greater root-mean-square (rms) surface roughness as measured by atomic force microscopy (AFM) for nanostructured compared with respective conventional metals. For these reasons, results from the present in vitro study provided evidence that vascular stents composed of nanometer compared with micron-sized metal particles (specifically, either cp Ti or CoCrMo) may invoke cellular responses promising for improved vascular stent applications.
在人体中，血管细胞持续与因血管壁中嵌入蛋白质（如胶原蛋白和弹性蛋白）而具有纳米结构表面特征的组织相互作用。尽管如此，旨在恢复血流的血管支架却没有纳米级表面特征，而是在纳米尺度上表面光滑。作为开发下一代血管支架材料的第一步，这项体外研究的目的是研究与传统商业纯钛（cp Ti）和钴铬钼（CoCrMo）相比，纳米结构材料上血管细胞（具体为内皮细胞和血管平滑肌细胞）的黏附情况。与传统的微米级颗粒不同，纳米结构的cp Ti和CoCrMo压块分别通过使用cp Ti或CoCrMo纳米颗粒制成。本研究结果首次表明，黏附4小时后，与传统cp Ti和CoCrMo相比，纳米结构材料上的内皮细胞和血管平滑肌细胞黏附增加。此外，与各自的传统对应物相比，纳米结构cp Ti和CoCrMo上内皮细胞与血管平滑肌细胞的比例增加。另外,与传统金属相比，内皮细胞和血管平滑肌细胞在纳米结构金属上具有更好的铺展形态。总体而言，血管细胞在CoCrMo上的黏附比在cp Ti上更好。表面表征研究结果表明，与各自的传统金属相比，纳米结构材料的化学性质相似，但通过原子力显微镜（AFM）测量的均方根（rms）表面粗糙度显著更大。基于这些原因，本体外研究结果提供了证据，表明与微米级金属颗粒（具体为cp Ti或CoCrMo）相比，由纳米级金属颗粒组成的血管支架可能引发对改善血管支架应用有前景的细胞反应。
