title: Intracellular delivery of nanoparticles and DNAs by IR9 cell-penetrating peptides.
abstract: Cell-penetrating peptides (CPPs) comprised of basic amino residues are able to cross cytoplasmic membranes and are able to deliver biologically active molecules inside cells. However, CPP/cargo entrapment in endosome limits biomedical utility as cargoes are destroyed in the acidic environment. In this study, we demonstrate protein transduction of a novel CPP comprised of an INF7 fusion peptide and nona-arginine (designated IR9). IR9 noncovalently interacts with quantum dots (QDs) and DNAs to form stable IR9/QD and IR9/DNA complexes which are capable of entering human A549 cells. Zeta-potentials were a better predictor of transduction efficiency than gel shift analysis, emphasizing the importance of electrostatic interactions of CPP/cargo complexes with plasma membranes. Mechanistic studies revealed that IR9, IR9/QD and IR9/DNA complexes may enter cells by endocytosis. Further, IR9, IR9/QD and IR9/DNA complexes were not cytotoxic at concentrations below 30, 5 and 20.1 µM, respectively. Without labor intensive production of fusion proteins from prokaryotes, these results indicate that IR9 could be a safe carrier of genes and drugs in biomedical applications.
authors.affiliation: Department of Natural Resources and Environmental Studies, National Dong Hwa University, Hualien, Taiwan.
authors.forename: Betty R
authors.initials: BR
authors.lastname: Liu
authors.forename: Ji-Sing
authors.initials: JS
authors.lastname: Liou
authors.forename: Yue-Wern
authors.initials: YW
authors.lastname: Huang
authors.forename: Robert S
authors.initials: RS
authors.lastname: Aronstam
authors.forename: Han-Jung
authors.initials: HJ
authors.lastname: Lee
mesh_terms: D016923:Cell Death / Q000187:drug effects; D057846:Cell-Penetrating Peptides / Q000494:pharmacology*; D004247:DNA / Q000378:metabolism*; D016503:Drug Delivery Systems; D004705:Endocytosis / Q000187:drug effects; D005434:Flow Cytometry; D006801:Humans; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism*; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D053758:Nanoparticles / Q000737:chemistry*; D010957:Plasmids / Q000378:metabolism; D045663:Quantum Dots; D055672:Static Electricity
chemical_list: D057846:Cell-Penetrating Peptides; D004247:DNA