Ion beam induced nanometric structure and oligopeptide adsorption on patterned polymer surfaces

The adsorption process of the H-Arg-Gly-Asp-OH oligopeptide (RGD sequence) onto surfaces of poly(ethyleneterephtalate) and poly(caprolactone) patterned by 50 keV Ar+ ion beams is discussed. The irradiation through masks patterned with micrometric features was employed to create grooves and/or pits of nanometric depth. Both XPS and Imaging time-of-flight secondary-ion mass spectrometry (ToF-SIMS) measurements showed that incubation of the polymer samples with RGD solutions produces a preferential adsorption on the ion-irradiated areas of the PCL surfaces, while only a negligible adsorption is obtained onto PET. The adsorption behaviour of the RGD is found to correlate with the surface nanostructuring induced by the ion irradiation