Cell Penetrating Peptides, Novel Vectors for Gene Therapy
Mechanical Engineering, Biomedical Engineering and Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA
Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15201, USA
Author to whom correspondence should be addressed.
Pharmaceutics 2020, 12(3), 225; https://doi.org/10.3390/pharmaceutics12030225
Received: 5 February 2020 / Revised: 27 February 2020 / Accepted: 1 March 2020 / Published: 3 March 2020
(This article belongs to the Special Issue Non-Viral Gene Delivery Systems)
Cell penetrating peptides (CPPs), also known as protein transduction domains (PTDs), first identified ~25 years ago, are small, 6–30 amino acid long, synthetic, or naturally occurring peptides, able to carry variety of cargoes across the cellular membranes in an intact, functional form. Since their initial description and characterization, the field of cell penetrating peptides as vectors has exploded. The cargoes they can deliver range from other small peptides, full-length proteins, nucleic acids including RNA and DNA, liposomes, nanoparticles, and viral particles as well as radioisotopes and other fluorescent probes for imaging purposes. In this review, we will focus briefly on their history, classification system, and mechanism of transduction followed by a summary of the existing literature on use of CPPs as gene delivery vectors either in the form of modified viruses, plasmid DNA, small interfering RNA, oligonucleotides, full-length genes, DNA origami or peptide nucleic acids.