Department of Biohybrid & Medical Textiles (BioTex), AME - Institute of Applied Medical Engineering, Helmholtz Institute, RWTH Aachen University, Aachen, Germany.
Faculty of Science and Engineering, Aachen-Maastricht Institute for Biobased Materials, Maastricht University, Geleen, The Netherlands.
Artif Organs. 2020 Oct;44(10):E419-E433. doi: 10.1111/aor.13712. Epub 2020 May 14.
Endothelialized oxygenator devices (EndOxy) with a physiological, nonthrombogenic, and anti-inflammatory surface offer the potential to overcome current shortcomings of conventional extracorporeal membrane oxygenation such as complications like thromboembolism and bleeding that deteriorate adequate long-term hemocompatibility. The approach of endothelialization of gas exchange membranes, and thus the formation of a nonthrombogenic and anti-inflammatory surface, is promising. In this study, we investigated the mid-term shear stress resistance as well as gas transfer rates and cell densities of endothelial cells seeded on RGD-conjugated polydimethylsiloxane (RGD-PDMS) gas exchange membranes under dynamic conditions. Human umbilical vein endothelial cells were seeded on RGD-PDMS and exposed to defined shear stresses in a microfluidic bioreactor. Endothelial cell morphology was assessed by bright field microscopy and immunocytochemistry. Furthermore, gas transfer measurement of blank, RGD-conjugated, and endothelialized PDMS oxygenator membranes was performed. RGD-PDMS gas exchange membranes proved suitable for the dynamic culture of endothelial cells for up to 21 days at a wall shear stress of 2.9 dyn/cm . Furthermore, the cells resisted increased wall shear stresses up to 8.6 dyn/cm after a previous dynamic preculture of each one hour at 2.9 dyn/cm and 5.7 dyn/cm . Also, after a longer dynamic preculture of three days at 2.9 dyn/cm and one hour at 5.7 dyn/cm , increased wall shear stresses of 8.6 dyn/cm were tolerated by the cells and cell integrity could be remained. Gas transfer (GT) tests revealed that neither RGD conjugation nor endothelialization of RGD-PDMS significantly decrease the gas transfer rates of the membranes during short-term trials. Gas transfer rates are stable for at least 72 hours of dynamic cultivation of endothelial cells. Immunocytochemistry showed that the cell layer stained positive for typical endothelial cell markers CD31 and von Willebrand factor (VWF) after all trials. Cell density of EC on RGD-PDMS increased between 3 and 21 days of dynamic culture. In this study, we show the suitability of RGD-PDMS membranes for flow resistant endothelialization of gas-permeable membranes, demonstrating the feasibility of this approach for a biohybrid lung.
具有生理、非血栓形成和抗炎表面的内皮化氧合器设备 (EndOxy) 有潜力克服传统体外膜肺氧合的当前缺点，例如血栓栓塞和出血等并发症，这些并发症会降低长期的血液相容性。气体交换膜的内皮化方法，从而形成非血栓形成和抗炎表面，是有前途的。在这项研究中，我们研究了在动态条件下，内皮细胞接种在 RGD 修饰的聚二甲基硅氧烷 (RGD-PDMS) 气体交换膜上的中期剪切应力阻力以及气体转移率和细胞密度。将人脐静脉内皮细胞接种在 RGD-PDMS 上，并在微流控生物反应器中暴露于规定的剪切应力下。通过明场显微镜和免疫细胞化学评估内皮细胞形态。此外，还对空白、RGD 修饰和内皮化 PDMS 氧合器膜进行了气体转移测量。RGD-PDMS 气体交换膜适合在 2.9 dyn/cm 的壁剪切应力下动态培养内皮细胞长达 21 天。此外，在先前在 2.9 dyn/cm 和 5.7 dyn/cm 下每个小时动态预培养后，细胞可以抵抗增加的壁剪切应力，高达 8.6 dyn/cm。即使在 2.9 dyn/cm 下进行三天的动态预培养和 5.7 dyn/cm 下一小时的动态预培养后，细胞也可以耐受 8.6 dyn/cm 的增加壁剪切应力，并且可以保持细胞完整性。气体转移 (GT) 测试表明，无论是 RGD 修饰还是 RGD-PDMS 的内皮化都不会在短期试验中显著降低膜的气体转移率。在至少 72 小时的内皮细胞动态培养过程中，气体转移率是稳定的。免疫细胞化学显示，在所有试验后，细胞层对典型的内皮细胞标志物 CD31 和血管性血友病因子 (VWF) 呈阳性染色。在动态培养 3 至 21 天后，EC 在 RGD-PDMS 上的细胞密度增加。在这项研究中，我们展示了 RGD-PDMS 膜对于透气膜的耐流内皮化的适用性，证明了这种方法对于生物杂交肺的可行性。
