Aggregation morphology of synthetic peptidic amphiphiles

Abstract

Peptidic amphiphiles containing various homo-oligopeptides were synthesized. Their aggregation morphologies in aqueous dispersion were studied using dark-field optical microscopy. The amphiphile containing three glycine residues formed amorphous precipitates. The amphiphile containing three sarcosine residues formed novel twisted ribbon-like aggregates with a long pitch (15–25 μm). The amphiphile containing three proline residues formed fibrous helical superstructures (50–70 μm in length). The last two morphologies were stable only at temperatures below the phase transition temperature. Different aggregation morphologies of the peptidic amphiphiles in aqueous dispersion were observed in the presence and absence of amide (NH) protons. Small amounts of additives altered the morphological structure of the aggregates on incubation.