Cell-penetrating peptides (CPPs) as a vector for the delivery of siRNAs into cells

Cell-penetrating peptides (CPPs)'' is an inclusive term describing relatively small peptides (6-30 amino acid residues) having membrane translocation activity. Due to their efficacy in cellular internalisation and the accompanying low cytotoxicity, CPPs are regarded as promising vectors for intracellular delivery of various membrane-impermeable bioactive molecules. This review provides an overview of the current approaches and describes the potential of CPP-based siRNA delivery systems, specifically those using arginine-rich CPPs.