The role of fibronectin in cell adhesion to spiral patterned TiO2 nanoparticles.

Spiral micropatterned surfaces of decreasing dimensions were produced by photo-immobilizing a photo-reactive hyaluronan (Hyal) derivative on TiO2 nanoparticles. The microstructured surfaces were characterized by both scanning electron microscopy and atomic force microscopy analysis. The behavior, of both endothelial cells (HCAEC) and tumoral mouse fibroblasts (NIH3T3) on the patterned surfaces was evaluated. HCAEC adhered only to the TiO2 nanoparticles avoiding contact with the Hyal. NIH3T3 adhered to and completely covered the TiO2 spiral but prolonging the culture time, it also covered the external photo-immobilized Hyal surface. The role of fibronectin to mediate cell adhesion to the TiO2 pattern surfaces was evaluated by experiments with blocked fibronectin membrane receptors on both HCAEC and NIH3T3. The results showed the absence of any adhering cells. Therefore, fibronectin seemed to be the only key protein in mediating cell adhesion to these TiO2 substrates.