Vascular cell responses to ECM produced by smooth muscle cells on TiO2 nanotubes

Abstract

There is an increasing interest in developing new methods to promote biocompatibility of biomedical materials. The TiO2 nanotubes with the tube diameter of 30nm were prepared by anodization. The response behavior of the human umbilical vein endothelial cell (HUVEC) and human umbilical artery smooth muscle cell (HUASMC) to these different nanotube sizes was investigated. Compared to the flat Ti, the growth and viability of HUVEC are prohibited, but there was no significant difference of HUASMC on 30nm TiO2 nanotubes. In this study, extracellular matrix (ECM) as a complex cellular environment which provides structural support to cells and regulates the cells functions was further used to modify the biological properties of TiO2 nanotubes. The ECM secreted from HUASMC was successfully deposited onto the 30nm TiO2 nanotubes. Moreover, immunofluorescence staining of common ECM components, such as fibronectin, laminin and type IV collagen, also indicated the successful ECM-covering on nanotube surfaces. Interestingly, the surface of ECM-covered TiO2 nanotubes significantly improved the proliferation of HUVECs in vitro. This suggested that the ECM secreted from HUASMCs on the TiO2 nanotubular surface could further improve the HUVECs adhesion and proliferation.