Drug Delivery with Designed Peptide Assemblies.

Self-assembly of designed synthetic peptides is a versatile strategy to generate functional materials for many applications. Given the biological relevance of their amino acid composition, one logical application for this class of materials lies in drug and therapeutic delivery. Peptide design alters the ultimate device form factor, ranging from circulating nanostructures to locally applied hydrogel depots. This growing field has progressed recently from methods for the simple solubilization of hydrophobic drugs to 'smart' carriers that deploy drug in response to a disease biomarker. The drug itself may act as a functional driver directing the assembly of a conjugated peptide. Furthermore, the peptide may itself have properties of a drug, both through presented bioactivity and by drug-like function of assemblies interfacing with cells or tissues. Given the exciting advances in the use of peptide assemblies for drug delivery, this review outlines different peptide self-assembly designs, highlights the advantages of using peptide self-assembly in the delivery of various classes of therapeutics, and demonstrates how advanced functionalities such as targeting and disease responsiveness can be built into designed peptide systems. Additionally, we provide commentary on the opportunities and challenges ahead in this growing field.