Cell orientation on a stripe-micropatterned surface

Stripe-micropatterned surfaces have recently been a unique tool to study cell orientation. In this paper, we prepared, by the photolithography transfer technique, stable gold (Au) micropatterns on PEG hy-drogel surfaces with defined cell-resistant (PEG hydrogel) and cell-adhesive (gold microstripes) prop-erties. 3T3 fibroblasts were cultured on Au-microstripe surfaces to observe cell adhesion and orienta-tion. Five statistical parameters were defined and used to describe cell orientation on micropatterns. With the increase of inter-stripe distance, the orientational order parameter, the ratio of long and short axes of a cell, and the occupation fraction of cells on stripes increased gradually, whereas the spreading area of a single cell decreased. The abrupt changes of these four parameters did not happen at the same inter-distance. The adhesion ratio of a cell on Au stripes over cell spreading area did not change monotonically as a function of inter-stripe distance. The combination of the 5 statistical pa-rameters represented well the cell orientation behaviors semi-quantitatively.