Cell sensing and response to micro- and nanostructured surfaces produced by chemical and topographic patterning.

Chemical and topographic substrate surface patterning is recognized as a powerful tool for regulating cell functions. We discuss the relative role of scale and pattern of chemically and topographically patterned surfaces in regulating cell behavior. Chemical patterning achieved using spatial cell-adhesive molecular organization regulates different cell functions depending on its scale (micropattern for cell patterning and derived cell functions, nanopattern for collective cell functions such as adhesion, proliferation, and differentiation). In chemical patterning, a direct and specific cell-sensing mechanism such as integrin-ligand binding governs. Alternatively, topographic modification affects different cell functions depending on its pattern (anisotropic ridges and grooves for contact-guided cell alignment, isotropic textures having randomly or evenly distributed topographic features for collective functions). For all topographic patterns, micro- or nanotopographic scale determines whether specific cell reactions occur. If the topography effect were assessed under the same surface chemistry, cell adaptation processes would play a major role in cell sensing and response to topography, largely independent of mediation via differences in adsorbed proteins. Controlling scale and pattern in chemical and topographic substrate patterning would help significantly to develop purpose-specific cell-regulating cues in various biomedical applications, including tissue engineering, implants, cell-based biosensors, microarrays, and basic cell biology.