The self-organized differentiation from MSCs into SMCs with manipulated micro/Nano two-scale arrays on TiO surfaces for biomimetic construction of vascular endothelial substratum.

The endothelialization on biomaterial surface has been seen as an important strategy to solve the clinic problems with the cardiovascular implant device. However, the continuous and large surfaces such as artificial heart or artificial cardiac valve cannot maintain the structural and functional stability of the endothelium without the supply of substratum structures. Herein, we combined the micro/nano technology of material surface engineering and the tissue engineering technology to construct the biomimetic vascular endothelial substratum for high quality and complete endothelialization through inducing self-organized differentiation from MSCs to SMCs, controlling their self-aggregation structure and further manipulating micro-tissue on the surface. In the present work, the micro/nano two-scale features of surface were manipulated by preparing the micro arrays of TiO nanotubes on titanium surface. The responses of MSCs to these surfaces revealed that the MSCs could be highly regulated and then their self-organized differentiation to SMCs could be induced and improved based on anchoring of the adhesion complex protein and traction of F-actin adjusted by the micro/nano features of the surfaces. Besides, SMCs' self-aggregation structure could also be adjusted effectively by manipulating micro/nano features on two-scale surfaces, and three types of tissue-like structures could be achieved for the further use in formation and surface manipulation of micro-tissue and biomimetic construction of vascular endothelial substratum.