Abstract
The strategies to regulate cell differentiation, growth, and proliferation are fundamental for tissue engineering in regenerative. Our aim here is to provide a basis for noninvasive and stable control of these cellular processes by clarifying the effect of extracellular microgrooved structure. We fabricated a microstructured cell culture substrate consisting of a major groove to guide a cell body penetration and the branched grooves to guide cellular protrusion into them. We seeded the cells on the substrate and evaluate the effect of the microgrooves on the cellular distribution of actin and phosphorylated myosin. About a half of the cells penetrated into the grooved structure, whereas the other cells were grown on the grooves. In both of the two groups, the cells show various morphologies. A common feature in the penetrated groups was disappearance of the stress fibers. Furthermore, these cells had a tendency to form thin actin protrusions without myosin, which is assumed to be filopodia, into the branched grooves. The result of the observation of the phosphorylated myosin together with the actin filaments indicates the downregulation of Rho GTPase in the cell body in the major groove and upregulation of cdc42 neat the base of the branched groove. Based on the findings, the microgrooved structure is expected to be used for external control of cellular distribution of actomyosin by affecting small GTPases.
