Directly nanopatternable nanoporous titania - Application to cell growth engineering

Titanium dioxide (TiO2) is a well-known biocompatible material with important applications in many fields of biomedicine. Here we show our results on the development of a new TiO2 based sol-gel system that can act as negative tone resist for both ultraviolet (UV) and electron beam (EB) lithographies. The system allows the direct patterning of high resolution structures (down to 40 nm). Moreover, it allows the preparation of nanopatterned nanoporous TiO2 simply by changing the conditions of resist development. The presented system can be used as functional tool for the systernatic investigation of cell behavior with respect to a complex topographic texture of the substrate (cell guidance). TiO2 structures of different dimensions, geometries and nanoporosity, whose size ranges from a few hundred to a few tens nanometer, are obtained after UV and/or EB lithography. The adhesion of different cell lines, i.e., human osteosarcoma (HOS) and neuroblastoma (N2A), on the patterns is assessed and our results show that cells have a preference for TiO2 patterns with respect to glass.