Benavidez Tomás E, Wechsler Marissa E, Farrer Madeleine M, Bizios Rena, Garcia Carlos D
1 Department of Chemistry, Clemson University , Clemson, South Carolina.
2 Department of Biomedical Engineering, The University of Texas at San Antonio , San Antonio, Texas.
Tissue Eng Part C Methods. 2016 Jan;22(1):69-75. doi: 10.1089/ten.TEC.2015.0315. Epub 2015 Dec 15.
The present article reports on the effect of electric potential on the adsorption of collagen type I (the most abundant component of the organic phase of bone) onto optically transparent carbon electrodes (OTCE) and its mediation on subsequent adhesion of adult, human, mesenchymal stem cells (hMSCs). For this purpose, adsorption of collagen type I was investigated as a function of the protein concentration (0.01, 0.1, and 0.25 mg/mL) and applied potential (open circuit potential [OCP; control], +400, +800, and +1500 mV). The resulting substrate surfaces were characterized using spectroscopic ellipsometry, atomic force microscopy, and cyclic voltammetry. Adsorption of collagen type I onto OTCE was affected by the potential applied to the sorbent surface and the concentration of protein. The higher the applied potential and protein concentration, the higher the adsorbed amount (Γcollagen). It was also observed that the application of potential values higher than +800 mV resulted in the oxidation of the adsorbed protein. Subsequent adhesion of hMSCs on the OTCEs (precoated with the collagen type I films) under standard cell culture conditions for 2 h was affected by the extent of collagen preadsorbed onto the OTCE substrates. Specifically, enhanced hMSCs adhesion was observed when the Γcollagen was the highest. When the collagen type I was oxidized (under applied potential equal to +1500 mV), however, hMSCs adhesion was decreased. These results provide the first correlation between the effects of electric potential on protein adsorption and subsequent modulation of anchorage-dependent cell adhesion.
本文报道了电势对I型胶原蛋白（骨骼有机相的最主要成分）在光学透明碳电极（OTCE）上吸附的影响，以及其对成人人类间充质干细胞（hMSCs）后续黏附的介导作用。为此，研究了I型胶原蛋白的吸附与蛋白质浓度（0.01、0.1和0.25mg/mL）以及施加电势（开路电势[OCP；对照]、+400、+800和+1500mV）之间的关系。使用光谱椭偏仪、原子力显微镜和循环伏安法对所得的基底表面进行了表征。I型胶原蛋白在OTCE上的吸附受施加到吸附剂表面的电势和蛋白质浓度的影响。施加的电势和蛋白质浓度越高，吸附量（Γ胶原蛋白）越高。还观察到，施加高于+800mV的电势会导致吸附蛋白质的氧化。在标准细胞培养条件下，hMSCs在预先涂覆有I型胶原蛋白膜的OTCE上2小时后的后续黏附受预先吸附在OTCE基底上的胶原蛋白程度的影响。具体而言，当Γ胶原蛋白最高时，观察到hMSCs黏附增强。然而，当I型胶原蛋白被氧化时（在等于+1500mV的施加电势下），hMSCs的黏附减少。这些结果首次提供了电势对蛋白质吸附的影响与随后对锚定依赖性细胞黏附的调节之间的相关性。
