title: Cell penetrating peptides: intracellular pathways and pharmaceutical perspectives.
abstract: Cell penetrating peptides, generally categorized as amphipathic or cationic depending on their sequence, are increasingly drawing attention as a non-invasive delivery technology for macromolecules. Delivery of a diverse set of cargo in terms of size and nature ranging from small molecules to particulate cargo has been attempted using different types of cell penetrating peptides (CPPs) in vitro and in vivo. However, the internalization mechanism of CPPs is an unresolved issue to date, with dramatic changes in view regarding the involvement of endocytosis as a pathway of internalization. A key reason for the lack of consensus on the mechanism can be attributed to the methodology in deciphering the internalization mechanism. In this review, we highlight some of the methodology concerns, focus more on the internalization pathway and also provide a novel perspective about the intracellular processing of CPPs, which is a crucial aspect to consider when selecting a cell penetrating peptide as a drug delivery system. In addition, recent applications of cell penetrating peptides for the delivery of small molecules, peptides, proteins, oligonucleotides, nanoparticles and liposomes have been reviewed.
authors: Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California 90089, USA.
authors: Leena N
authors: LN
authors: Patel
authors: Jennica L
authors: JL
authors: Zaro
authors: Wei-Chiang
authors: WC
authors: Shen
mesh_terms: D021581:Active Transport, Cell Nucleus; D000595:Amino Acid Sequence; D002462:Cell Membrane / Q000378:metabolism*; D002463:Cell Membrane Permeability; D004337:Drug Carriers; D016503:Drug Delivery Systems; D004705:Endocytosis; D011992:Endosomes / Q000378:metabolism; D008081:Liposomes; D008969:Molecular Sequence Data; D053758:Nanoparticles; D010455:Peptides / Q000493:pharmacokinetics*
chemical_list: D004337:Drug Carriers; D008081:Liposomes; D010455:Peptides