Abstract: Provided is a peptide including X-(Xaa1)a-(Xaa2)b-Y-(Xaa3)c-(Xaa4)d-Z, or a salt or amide thereof, in which each of X and Z is independently selected from Asn, Cys, Gln, Gly, Ser, Thr and Tyr; in which one of Xaa1 and Xaa2 is His and the other of Xaa1 and Xaa2 is Arg; in which one of Xaa3 and Xaa4 is His and the other of Xaa3 and Xaa4 is Arg; in which the amino functional group of X is, optionally, acylated; in which the carboxylate functional group of Z is, optionally, amidated; in which Y is selected from Ala and Trp; in which each of a and d is independently an integer from 2 to 4; and each of b and c is independently an integer from 2 to 4. The peptide may be used in therapeutic approaches.

Abstract: The present invention is directed to a peptide for the delivery of anionic materials, such as anionic therapeutic agents, across a biological barrier, and methods of use thereof. The invention relates to a peptide comprising, or consisting of: X-(Xaa1)a-(Xaa2)b-Y-(Xaa3)c-(Xaa4)d-Z, in which each of X and Z is independently selected from Asn, Cys, Gln, Gly, Ser, Thr and Tyr; in which one of Xaa1 and Xaa2 is His and the other of Xaa1 and Xaa2 is Arg; in which one of Xaa3 and Xaa4 is His and the other of Xaa3 and Xaa4 is Arg; in which the amino functional group of X is, optionally, acylated; in which the carboxylate functional group of Z is, optionally, amidated; in which Y is selected from Ala and Trp; in which each of a and d is independently 2 to 4; and each of b and c is independently 2 to 4, or a salt or amide thereof.