Light-induced molecular adsorption of proteins (LIMAP) allows for quantitative sub-micrometer-resolution printing of multiple biomolecules. Surface-bound gradients are patterned within minutes over an entire glass cover-slip. LIMAP is used to perform selective immuno-assays, to dynamically control the adhesion of individual cells, and to achieve hierarchical co-cultures instrumental for tissue engineering.

Neurons are sensitive to topographical cues provided either by in vivo or in vitro environments on the micrometric scale. We have explored the role of randomly distributed silicon nano-pillars on primary hippocampal neurite elongation and axonal differentiation. We observed that neurons adhere on the upper part of nano-pillars with a typical distance between adhesion points of about 500nm. These neurons produce less neurites, elongate faster, and differentiate an axon earlier than those grown on flat silicon surfaces. Moreover, when confronted to a differential surface topography, neurons specify an axon preferentially onto nano-pillars. As a whole, these results highlight the influence of the physical environment in many aspects of neuronal growth.