Abstract:

A technique for imparting micro- and nanostructured topography into the surface of freestanding thin sheets of chitosan is described. Both micro- and nanometric surface structures have been produced using soft lithography. The soft lithography method, based on solvent evaporation, has allowed structures sim60 nm tall and sim500 × 500 nm2 to be produced on freestanding sim0.5 mm thick sheets of the polymer when cured at 293 K, and structures sim400 nm tall and 5 × 5 mum2 to be produced when cured at 283 K. Nonstructured chitosan thin sheets (sim200 mum thick) show excellent optical transmission properties in the visible portion of the electromagnetic spectrum. The structured sheets can be used for applications where optical microscopic analysis is required, such as cell interaction experiments and tissue engineering.