Department of Biomedical Engineering, Duke University, 136 Hudson Hall, Box 90281, Durham, NC 27708, USA.
Biomaterials. 2011 Nov;32(33):8356-63. doi: 10.1016/j.biomaterials.2011.07.066. Epub 2011 Aug 15.
Titanium (Ti) is commonly utilized in many cardiovascular devices, e.g. as a component of Nitinol stents, intra- and extracorporeal mechanical circulatory assist devices, but is associated with the risk of thromboemboli formation. We propose to solve this problem by lining the Ti blood-contacting surfaces with autologous peripheral blood-derived late outgrowth endothelial progenitor cells (EPCs) after having previously demonstrated that these EPCs adhere to and grow on Ti under physiological shear stresses and functionally adapt to their environment under flow conditions ex vivo. Autologous fluorescently-labeled porcine EPCs were seeded at the point-of-care in the operating room onto Ti tubes for 30 min and implanted into the pro-thrombotic environment of the inferior vena cava of swine (n = 8). After 3 days, Ti tubes were explanted, disassembled, and the blood-contacting surface was imaged. A blinded analysis found all 4 cell-seeded implants to be free of clot, whereas 4 controls without EPCs were either entirely occluded or partially thrombosed. Pre-labeled EPCs had spread and were present on all 4 cell-seeded implants while no endothelial cells were observed on control implants. These results suggest that late outgrowth autologous EPCs represent a promising source of lining Ti implants to reduce thrombosis in vivo.
钛（Ti）常用于许多心血管设备中，例如作为 Nitinol 支架、体内和体外机械循环辅助设备的组成部分，但与血栓形成的风险相关。我们建议通过在 Ti 与血液接触的表面衬上自体外周血衍生的晚期出芽内皮祖细胞（EPC）来解决这个问题，此前我们已经证明这些 EPC 在生理剪切力下能够附着和在 Ti 上生长，并在体外流动条件下适应其环境。将自体荧光标记的猪 EPC 在手术室的床边接种到 Ti 管上 30 分钟，然后将其植入猪下腔静脉的促血栓环境中（n = 8）。3 天后，取出 Ti 管，拆开，对与血液接触的表面进行成像。一项盲法分析发现，所有 4 个接种细胞的植入物均无血栓，而没有 EPC 的 4 个对照物则完全闭塞或部分血栓形成。预先标记的 EPC 已经扩散并存在于所有 4 个细胞接种的植入物上，而在对照植入物上则没有观察到内皮细胞。这些结果表明，晚期出芽的自体 EPC 是一种有前途的 Ti 植入物衬里来源，可减少体内血栓形成。
