Drug Delivery Peptides

Disclosed is a peptide comprising the sequence: H2N-Gly-Phe-D-Thr-Gly-Phe-Leu-Ser-CONH2, wherein the serine residue may be functionalized with sugar residues; other aminoacids can replace the first 2 amino acids of the N-terminal portion, the order of which can be reversed, and their no. may be different from 2. Thus, a data anal. obtained from the in vivo study with fluorescence microscopy clearly shows that the nanoparticles obtained with PLGA modified with the peptide H2N-Gly-Phe-D-Thr-Gly-Phe-Leu-Ser-CONH2, and to a greater extent with the peptide H2N-Gly-Phe-D-Thr-Gly-Phe-Leu-SerO-.beta.-D-glucose-CONH2 are able to cross the BBB and penetrate into the brain parenchyma. However, the nanoparticles only constituted by PLGA are unable to cross the blood-brain barrier, and remain in the blood vessels.