The Role of Vitronectin in the Attachment and Spatial Distribution of Bone-derived Cells on Materials with Patterned Surface Chemistry

In recent years a central objective of tissue engineering has been understanding the interaction of cells with biomaterial surfaces. In this study we examined the protein adsorption events necessary to control the attachment and the subsequent spatial distribution of bone-derived cells exposed to chemically modified surfaces. Silane chemistry and photolithography techniques were used to create substrates with alternating regions of an aminosilane, N-(2-aminoethyl)-3-aminopropyl-trimethoxysilane (EDS), along side an alkylsilane, dimethyldichlorosilane (DMS), on quartz surfaces. Sera depleted of fibronectin (Fn), vitronectin (Vn), or both were used to determine if these proteins were necessary for the initial attachment and spatial distribution of bone-derived cells exposed to modified surfaces in vitro. The kinetics and mechanisms of the spatial distribution of cells were examined using light microscopy and digital image acquisition and subsequently were analyzed. Compared to complete serum, the use of serum depleted of fibronectin with vitronectin included had minimal effect on the cell attachment, spreading, and spatial distribution on the EDS regions of the surface. However, the use of serum depleted of vitronectin with or without fibronectin included resulted in greatly reduced cell attachment and spreading. Thus the presence of vitronectin was required for the attachment, spreading, and spatial distribution of bone-derived cells exposed to EDS/DMS-patterned surfaces.