Three dimensional spatial separation of cells in response to microtopography.

Cellular organization, migration and proliferation in three-dimensions play a critical role in numerous physiological and pathological processes. Nano- and micro-fabrication approaches have demonstrated that nano- and micro-scale topographies of the cellular microenvironment directly impact organization, migration and proliferation. In this study, we investigated these dynamics of two cell types (NIH3T3 fibroblast and MDCK epithelial cells) in response to microscale grooves whose dimensions exceed typical cell sizes. Our results demonstrate that fibroblasts display a clear preference for proliferating along groove ridges whereas epithelial cells preferentially proliferate in the grooves. Importantly, these cell-type dependent behaviours were also maintained when in co-culture. We show that it is possible to spatially separate a mixed suspension of two cell types by allowing them to migrate and proliferate on a substrate with engineered microtopographies. This ability may have important implications for investigating the mechanisms that facilitate cellular topographic sensing. Moreover, our results may provide insights towards the controlled development of complex three-dimensional multi-cellular constructs.