A novel highly stable and injectable hydrogel based on a conformationally restricted ultrashort peptide

Nanostructures including hydrogels based on peptides containing non protein amino acids are being considered as platform for drug delivery because of their inherent biocompatibility and additional proteolytic stability. Here we describe instantaneous self-assembly of a conformationally restricted dipeptide, Leu Delta Phe, containing an alpha,beta-dehydrophenylalanine residue into a highly stable and mechanically strong hydrogel, under mild physiological aqueous conditions. The gel successfully entrapped several hydrophobic and hydrophilic drug molecules and released them in a controlled manner. Leu Delta Phe was highly biocompatible and easily injectable. Administration of an antineoplastic drug entrapped in the gel in tumor bearing mice significantly controlled growth of tumors. These characteristics make Leu Delta Phe an attractive candidate for further development as a delivery platform for various biomedical applications.