Imprinted Binary Colloidal Crystals Support Growth and Stemness of Mouse Embryonic Stem Cells

Stemness of mouse embryonic stem cells (mESCs) can be maintained in vitro using biophysical factors including surface topography. More specifically, multidirectional symmetries have shown promise in limiting cell-substrate interactions, yielding better stemness maintenance. Here, a parylene-C coating was deposited onto binary colloidal crystals (BCCs) to generate imprinted substrates with concave bowl-like micro/nanotopographies possessing multidirectional symmetry. Remarkably, the parylene coating is shown to have the fidelity to imprint sub-2 μm structures. The mESC response to these topographies observed in culture demonstrates the complementary influence of microtopography and nanotopography. While the nanoroughness associated with the small particle imprints appears to govern the attachment of cells, the microroughness associated with large particle imprints is able to limit the interaction of cells with the substrate thereby confining spreading. Our results demonstrate that imprinted BCCs with the combination of 5 μm (large) and 110 nm (small) particle imprints are able to provide spatially limited attachment of cells, resulting in improved colony shape, enhanced growth rate and upregulation of the expression of stemness markers of mESCs in culture in the presence of LIF. Our results are expected to contribute to the development of novel cell culture substrates for use in the efficient expansion of stem cells for tissue engineering and regenerative medicine applications.