(651c) PEG Based Hydrogels with Permeability Gradients for Enhanced Cell Function

  The development and synthesis of a bioartificial ECM-like network is currently challenged by incorporation of biomolecules with a gradient. To this end, we have investigated theoretical and experimental strategies to control incorporation of biomolecules within poly(ethylene glycol) (PEG) hydrogels based on surface initiated photopolymerization.  In this study, we compared biofunctional PEGDA hydrogels formed via bulk and surface initiated photopolymerization as environments to enhance cell survival and function. The trends obtained from experimental swelling measurements of RGDS functionalized PEG hydrogel membranes compare well with the mathematical model. The effects of different PEG hydrogel platforms formed via bulk or surface initiated polymerization on insulin secreting MIN6 cell viability/functionality have also been investigated in these functional PEG hydrogel systems. These platforms allow for incorporation of ligands and growth factors with a gradient, and include covalently bonded cell adhesion sequences and specific growth factors to promote cell survival and function. This study demonstrates the possibility of tailoring biomimetic environments such as thickness and crosslink density with the aid of mathematical models in highly permissive and biofunctional PEG hydrogels for enhancing cell migration and optimizing tissue formation with PEG hydrogels.