Influence of Structural Features on the Self-Assembly of Short Ionic Oligopeptides

We investigated the self-aggregation of 12 short ionic oligopeptides constituted by 4-7 amino acid residues to establish useful structure-property relationships that might be exploited in the biomedical field by using the concept of molecular Lego. We show that the critical aggregation concentration (CAC) of tetrapeptides decreases with increasing hydrophobicity of neutral residues. Additionally, the dependence of the CAC of isomeric oligopeptides on the distribution of amino acid residues confirms the high tendency to self-organization of molecules with alternating ionic and neutral residues. Indeed, atomic force microscopy (AFM) images recorded on oligopeptide solutions above the CAC show the presence of either fibrillar or spherical aggregates depending on oligopeptide structure and concentration, steric hindrance, solution pH, and time. The potential of the investigated oligopeptides in tissue engineering applications is supported by their in vitro cytocompatibility. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 889897, 2010