(446a) Matrix Interfacial Properties Control Cell Adhesion, Shape, Growth, and Differentiation

There is little or no data on how substrate hydrophobicity and other interfacial properties affect various cellular behavior such as adhesion, cell division, motility, growth, shape changes, and differentiation. Dissecting systematically the effect of interfacial properties on cellular behavior without altering the chemical and mechanical properties of the matrix?properties that are established to have a profound effect on cell behavior?is a daunting task. In this study, we have manipulated the matrix interfacial properties on stem cells by varying the hydrophobicity of the dangling pendant chains of the hydrogel matrix without altering key functional groups and the bulk mechanical properties. The incorporation of hydrophobic comonomers enhanced the adhesive properties of commonly used acrylamide hydrogels, which do not typically support cell adhesion. Time-lapse video analysis and quantification of cell adhesion reveals a remarkable correlation between pendant chain length (hydrophobicity) and cell adhesion, cell shape, and survival. There appears to be an optimal range of hydrophobicity which promotes cell adhesion, proliferation, and cell shape. Beyond controlling adhesion and growth of cells, the matrix hydrophobilicty also regulates the differentiation commitment of stem cells.