Chondrocyte morphology on polymer-silica nanocomposites prepared by sol-gel technique

Cell adhesion to synthetic materials is mediated by extracellular matrix proteins (including fibronectin (FN), laminin, and vitronectin) which adsorb on the substrate upon contact with physiological fluids in vivo or culture medium in vitro [1]. The concentration, distribution and mobility of the adsorbed protein layer on a surface play a fundamental role in the biofunctionality of a synthetic material and are clue factors to understand the biological response of a substrate. The (nano)incorporation of different amount of inorganic phase into a polymeric matrix is able to enhance the bioactivity of the substrate by, e.g., inducing the formation of an apatite layer but, on the other hand, on the short-time might influence drastically the initial cell-material behaviour, which modifies cell adhesion and morphology. We have prepared polymer-silica nanocompostites based on poly(2-hydroxyethyl acrylate), PHEA, by the simultaneous polymerisation of the organic and the silica phases in a sol-gel process. Besides, we have performed in vitro chondrocyte culture on the different hybrids and the cell-material interaction was shown to depend strongly on the presence of silica in the system.