Peptide ligand targeted delivery to EGFR Expressing Cancer Cells in Vitro and in Vivo

Epidermal growth factor receptor (EGFR) is an important cell surface protein that's over-expressed in many human cancer cells. We designed a novel peptide ligand (named D4) based on the crystal structure of EGFR that can bind to a surface pocket on EGFR. D4-PEG-lipid conjugates were made and used to modify liposome surface. Confocal fluorescence microscopy data showed that D4-liposome (D4-RL) bound strongly to EGFR high-expressing H1299 cells and were quickly endocytosed. In vivo, after tail vein injection, Cy5.5 labeled D4 peptides were seen to accumulate in H1299 xenograft tumor tissues. These data indicated that D4 may be an efficient peptide ligand for targeted drug and gene delivery to EGFR expressing tumors.