Peptide-based vesicles and droplets: a review

Peptide assembly is an increasingly important field of study due to the versatility, tunability and vast design space of amino acid based biomolecular assemblies. Peptides can be precisely engineered to possess various useful properties such as the ability to form supramolecular assemblies, desired response to pH, or thermal stability. These peptide supramolecular assemblies have diverse morphologies including vesicles, nanotubes, nanorods and ribbons. Of specific interest is the domain of engineering peptides that aggregate into spherical nanostructures due to their encapsulation properties: the ability to hold, transport and release chemical payloads in a controllable manner. This is invaluable to the fields of nanomedicine and targeted drug delivery. In this review, the state of the art in the domain of peptide-based vesicles and nanospheres is summarized. Specifically, an overview of the assembly of peptides into nanovesicles and nanospheres is provided. Both aromatic as well as aliphatic side chain amino acids are discussed. The domain of aromatic side chained amino acid residues is largely dominated by phenylalanine based peptides and variants thereof. Tyrosine also demonstrates similar aggregation properties. Both experimentally and computationally driven approaches are discussed. The domain of aliphatic amino acid residues based vesicles and droplets is broader, and details multiple amino acid residues such as alanine, valine, lysine, glycine, proline, and aspartic acid. Finally, a discussion on potential future directions is provided.