Retro-inverso carbohydrate mimetic peptides with annexin1-binding selectivity, are stable in vivo, and target tumor vasculature.

Previous research suggests that carbohydrate mimetic peptide IF7 (IFLLWQR) has an excellent targeting property to annexin1 (Anxa1), a specific marker on the tumor endothelium. However, IF7 is susceptible to proteolysis and has a poor stability in vivo. We prepared a D-amino acid, reverse sequence peptide of IF7, designated RIF7, to confer protease resistance while retaining bioactivity. Experimental results indicate that RIF7 had significantly increased stability and an increased receptor binding affinity than IF7, and this new moiety may represent a clinically relevant vehicle for anticancer drugs.