Electrostatic effects on the self-assembly mechanism of peptide amphiphiles

Abstract

Self-assembling peptide amphiphiles, synthesized through solid phase peptide synthesis – a bottom-up approach, have been used with various tissue engineering purposes. Peptide amphiphile molecules self-assemble into nanofibers, which form three dimensional networks mimicking the extracellular matrix. Electrostatic interactions affect the formation of nanofibers. The effect of charged groups on the peptides on nanofiber formation were studied in this work. Neutralization of the charged groups by pH change, electrolyte addition or addition of oppositely charged biomacromolecules triggered the aggregation of the peptides. To understand the controlled formation of the gels composed of peptide nanofibers better can help the researchers develop bioactive collagen mimetic nanofibers for tissue engineering studies and use them in angiogenesis. Results obtained by Fourier Transform Infrared Spectroscopy (FT-IR), Circular Dichroism (CD), Rheology, pH titration, Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM); as well as the potential of using the peptide amphiphile molecules to promote angiogenesis, are described.