Revealing the dependence of cell spreading kinetics on its spreading morphology using microcontact printed bronectin patterns

Abstract

Since the dawn of the in vitro cell cultures, how cells interact and proliferate within a given external environment has always been an important issue in the study of cell biology. It is now well-known that mammalian cells typically exhibit a three phase sigmoid spreading on encountering a substrate. To further these understanding, we examined the in uence of cell shape towards the second rapid expansion phase of spreading. Specifically, 3T3 fibroblasts were seeded onto silicon elastomer films made from polydimethylsiloxane, and micro-contact printed with various dimension of fibronectin stripes. Polydimethylsiloxane is adopted in our study for its biocompatibility, its ease in producing very smooth surfaces, and in the fabrication of micro-contact printing stamps. The substrate patterns are compared with respect to their in uence on cell spreading over time. Our studies reveal, during the early rapid expansion phase, 3T3 fibroblasts are found to spread radially following a ≈ t1:8 law; meanwhile, they proliferated in a lengthwise fashion on the striped patterns, following a ≈ t1 law. We account for the observed differences in kinetics through a simple geometric analysis which predicted similar trends. In particular, a t2 law for radial spreading cells, and a t1 law for lengthwise spreading cells.