Engineering of covalently immobilized gradients of RGD peptides on hydrogel scaffolds: Effect on cell behaviour

The aim of this study has been to design a system for the preparation of Polyethylene-glycol (PEG) based hydrogels with a controlled spatial distribution of covalently immobilised RGD adhesion signals in order to control and guide cell response for tissue engineering application. Gradients of immobilised RGD peptides were characterized by confocal microscopy analysis. Moreover, the effect of RGD spatial distribution on cell behaviour was evaluated by using mouse embryo fibroblasts NIH3T3. In particular, we observed cell adhesion and migration of fibroblasts seeded on RGD gradient compared to cells on control hydrogels having an uniform distribution of RGD. Our data suggest that a linear gradient of covalently immobilised adhesion signals affects cell behaviour. In particular, cells feel RGD gradient and oriented themselves and move along gradient direction.