Geometric microenvironment directs cell morphology on topographically patterned hydrogel substrates

Cell behavior is influenced by numerous factors in the physical environment, and a deep understanding of these interactions can lead to the design of better scaffolds for tissue engineering. In vitro substrates can be used to evaluate a wide range of factors, such as topography, and identify which show promise for further evaluating in vivo. Polyacrylamide hydrogels featuring a combinatorial, micropatterned array of posts with varied shape, width, and spacing were produced using a one-step technique. Substrates were covalently modified with collagen and seeded with D1 ORL UVA mesenchymal stem cells. Patterning was shown to direct several quantitative measures of cell morphology. Cell bodies tended to be located in gaps 15 μm and wider, but on top of posts when gaps were 5 μm and smaller. Cells on substrates with square posts and narrow gaps tended to elongate in the direction of gaps. Finally, smaller gaps on all substrates were also shown to influence the placement of cell extensions. The parameters identified may be incorporated into substrates to direct specific aspects of cell morphology.