Ultrashort peptides: minimum number in amino acid residues, maximum number in bioapplications.

Abstract

Ultra-short peptides are an intrigue new type of biomaterials for various bioapplications. Over the decades, peptides have evolved as biomaterials due to the ease of synthesis, ease of scaling up, feasibility to be functionalized/modified, and recognition by biological system1. Peptide-based hydrogels are widely used as scaffolds for encapsulation and delivery of drugs, genes and cells. They are made of natural amino acids. Thus they are non-immunogenic. They contain carboxylic and amine groups. Thus they can be easily functionalized with bioactive moieties. However, for peptides with more than 16 amino acid residues, they are expensive due to the high synthesis cost. As such, ultra-short peptides with only 2 to 7 amino acid residues stand out due to their easy and cost-effective synthesis, facile assembly in aqueous solution, biocompatibility and mechanical stability. These ultrashort peptides can form hydrogels without the addition of enzymes or other types of cross-linkers.