Identification of Peptide Ligands for Targeting to the Blood-Brain Barrier.

The technique of phage display was used in a murine brain perfusion model, to screen for new brain endothelium peptide ligands. Two selected phage clones showed affinity for human brain endothelium in vitro (hCMEC/D3). This affinity was not seen for other humanendothelial cells (HUVEC). When the selected phage were individually perfused through the murine brain, their brain affinity was 5 to 6-fold higher compared to a random control phage. These results indicate that two new peptide ligands have been identified that may be used for specific targeting of drugs to the blood-brain barrier.