Molhabilidade e interações moleculares em substratos peptídicos nanoestruturados

Abstract

Peptides are short sequences of amino acids that have attracted a lot of attention because of the great chemical diversity, allowing a vast number of different arrangements and bonds based on these molecules. Another interesting aspect is the biocompatibility of these peptidic nanomaterials. Several studies have shown the growth of peptide substrates when they are conveniently incubated under an atmosphere saturated with solvent vapor such as water. This feature opens up possibilities for the production of peptide compounds capable of modulating physicochemical properties of surface, with great potential for the development of biointerfaces. In this context, the understanding of the wettability properties of such substrates, as well as the surface interactions, are crucial to produce biointerfaces with the broad technological application. In this work, the peptides Penetratina, a piece of protein Antennapedia; TAT1, derived from the HIV virus; SV40, derived from the vacuole virus that attacks monkeys; and C105Y, alpha-1 antitrypsin derivatives, are used to produce nanostructured films on solid substrates and then contact angle analysis, AFM and circular dichroism are performed to obtain information on wettability and molecular interactions at the fluid/substrate interface, topology and conformation compositional. Dynamic contact angle measurements allow the use of a physical model in the context of kinetic-molecular theory, which describes wettability phenomena in terms of statistical dynamics. With the present study, the molecular interactions in the amorphous and nanostructured peptide films were determined, and the measurements showed that the increase in the equilibrium contact angle in the nanoestrurados films is due, among other factors, to the increased roughness, as evidenced by the AFM measures.