Self-assembly of nanodonut structure from a cone-shaped designer lipid-like peptide surfactant.

We report here the donut-shaped nanostructure formation from the self-assembly of a designer lipid-like amphiphilic cone-shaped peptide. The critical aggregation concentration was measured using dynamic light scattering in water and phosphate-buffered saline. The dynamic self-assembly of the peptide was also studied using atomic force microscopy. We have studied numerous peptides over 17 years, and this is the first time that we have ever observed the nanodonut structure from cone-shaped peptides. We propose a plausible self-assembling pathway of the nanodonut structure that was self-assembled through the fusion or elongation of spherical micelles. Furthermore, the bending of the nanostructure gives rise to the nanodonut structures as a result of the tension originating from the interaction of the cone-shaped peptide side chains. Our observations may be useful for further fine tuning the geometry and shape of a new class of designer peptides and their self-assembled supramolecular materials for diverse uses.