Fig. 6. Increasing Fibroblast-Substrate Adhesion by Increasing Surface Adhesive Ligand Density.
A. A hydroxycoumarin dye (excitation 350 nm) pre-conjugated to aPEG-RGD allows for gradient characterization; incorporating 5.8 and 15.6 mM aPEG-RGD into two layers yield a gradient of approximately 10 mM/mm. B. Absolute velocities and X velocities of 3T3s on indicated regions of hydrogels with RGD concentration gradients spanning a 5.8–15.6 mM range. Low and high indicates cells found on the low and high static concentration regions of the substrate; gradient indicates cells found at the mixing interface of the substrate. Positive X velocity indicates migration towards regions of increasing adhesive ligand density. (n > 50; mean ± S.E.M.; n.s., not significant). C. Mean displacement of particles embedded in PA hydrogels with 5.8 and 15.6 mM aPEG-RGD resulting from tractions of 3T3s in normal media. (n > 10; mean ± S.E.M.; *p < 0.05).