Peptide vectors as drug carriers

Abstract

During the last decade, several peptides have been described, such as SynB vectors [1] penetratin and Tat [2, 3] that allow the intracellular delivery of polar, biologically active compounds in vitro and in vivo [2, 4]. These peptides, belonging to various families, are heterogeneous in size (10 to 18 amino acids) and sequence (Tab. 1). However, all these peptides possess multiple positive charges and some of them share common features such as important theoretical hydrophobicity and helical moment (reflecting the peptide amphipathicity), the ability to interact with lipid membrane and to adopt a significant secondary structure upon binding to lipids. The facility with which they cross the membrane into the cytoplasm even when carrying hydrophilic molecules has provided a new and powerful tool in biomedical research [3, 4]. An even more difficult task was to use these peptide vectors to deliver drugs across the blood-brain barrier (BBB). This chapter emphasizes the use of peptide vectors for brain delivery.