MAPLE deposition of 3D micropatterned polymeric substrates for cell culture

3D micropatterned poly(lactide-co-glycolide)/polyurethane (PLGA/PU) substrates were produced by MAPLE deposition through masks and used for regulating the behavior of oral keratinocyte stem cells in response to topography. Flat PLGA/PU substrates were produced for comparison. 3D imaging of the PLGA/PU substrates and of the cultured cells was performed by Digital Holographic Microscopy. The micropatterns were in the shape of squares of 50 × 50 and 80 × 80 μm2 areas, ~1.8 μm in height and separated by 20 μm wide channels. It was found that substrate topography guided the adhesion of the cultured cells: on the smooth substrates the cells adhered randomly and showed no preferred orientation; in contrast, on the micropatterned substrates the cells adhered preferentially onto the squares and not in the separating channels. Furthermore, key properties of the cells (size, viability, proliferation rate and stem cell marker expression) did not show any dependence on substrate topography. The size of the cultured cells, their viability, the proportions of actively/slow proliferating cells, as well as the stem cell markers expressions, were similar for both flat and micropatterned substrates. Finally, it was found that the cells cultured on the PLGA/PU substrates deposited by MAPLE exhibited similar properties as the controls (i.e. cells cultured on glass slides), indicating the capability of the former to preserve the properties of the keratinocyte stem cells.