Rapid Production of Transparent Micro/Nanostructured Polymer Substrates for Biomedical Surface Interaction Studies

The increase in the number of investigations into biomedical interactions with structured substrates has produced a necessity for transparent, microand nanostructured surfaces. To facilitate research, it must be possible to use these structured surfaces in conjunction with established culturing and imaging apparatus available within a biomedical laboratory. Such surfaces can be produced using a rapid fabrication technique where freestanding, transparent, structured polymeric substrates are produced for use in cell-surface interaction experiments. The production method is based on a nanoimprint lithography (NIL) technique using silicon based moulds to emboss structure into the surface of biologically compatible thermoplastic polymers. The moulds are fabricated via deep reactive ion or focused ion beam lithographies. The polymers can then be sized to fit in existing cell culture plates, or can be employed with reusable silicon-based culture plates. Unstructured polymers fabricated using this technique have transparencies rivalling that of glass, and although the transparency of the microand nanostructured films is reduced slightly, they are still sufficiently transparent to be used with conventional transmission microscopes. Cells cultured on the micro/nanostructures can therefore be viewed both from above and through the substrate, allowing cell-structure interactions, which would normally be hidden by the bulk of the cell, to be viewed. The optical transparency of the structured polymers also allows them to be used in Published in: New nanotechnology research. Ed: Reece JP. 199-234. Nova Science Pub Inc. 2006 2 fluorescent techniques. The possibility of chemically functionalising the polymer surfaces further increases the useful applications of these substrates.