title: Delivery of siRNA Complexed with Palmitoylated α-Peptide/β-Peptoid Cell-Penetrating Peptidomimetics: Membrane Interaction and Structural Characterization of a Lipid-Based Nanocarrier System.
abstract: Proteolytically stable α-peptide/β-peptoid peptidomimetics constitute promising cell-penetrating carrier candidates exhibiting superior cellular uptake as compared to commonly used cell-penetrating peptides (CPPs). The aim of the present study was to explore the potential of these peptidomimetics for delivery of small interfering RNA (siRNA) to the cytosol by incorporation of a palmitoylated peptidomimetic construct into a cationic lipid-based nanocarrier system. The optimal construct was selected on the basis of the effect of palmitoylation and the influence of the length of the peptidomimetic on the interaction with model membranes and the cellular uptake. Palmitoylation enhanced the peptidomimetic adsorption to supported lipid bilayers as studied by ellipsometry. However, both palmitoylation and increased peptidomimetic chain length were found to be beneficial in the cellular uptake studies using fluorophore-labeled analogues. Thus, the longer palmitoylated peptidomimetic was chosen for further formulation of siRNA in a dioleoylphosphatidylethanolamine/cholesteryl hemisuccinate (DOPE/CHEMS) nanocarrier system, and the resulting nanoparticles were found to mediate efficient gene silencing in vitro. Cryo-transmission electron microscopy (cryo-TEM) revealed multilamellar, onion-like spherical vesicles, and small-angle X-ray scattering (SAXS) analysis confirmed that the majority of the lipids in the nanocarriers were organized in lamellar structures, yet coexisted with a hexagonal phase, which is important for efficient nanocarrier-mediated endosomal escape of siRNA ensuring cytosolic delivery. The present work is a proof-of-concept for the use of α-peptides/β-peptoid peptidomimetics in an efficient delivery system that may be more generally exploited for the intracellular delivery of biomacromolecular drugs.
authors.affiliation: Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen , Universitetsparken 2, DK-2100 Copenhagen O, Denmark.
authors.forename: Xiaona
authors.initials: X
authors.lastname: Jing
authors.affiliation: Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen , Universitetsparken 2, DK-2100 Copenhagen O, Denmark.
authors.forename: Camilla
authors.initials: C
authors.lastname: Foged
authors.affiliation: Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen , Universitetsparken 2, DK-2100 Copenhagen O, Denmark.
authors.forename: Birte
authors.initials: B
authors.lastname: Martin-Bertelsen
authors.affiliation: Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen , Universitetsparken 2, DK-2100 Copenhagen O, Denmark.
authors.forename: Anan
authors.initials: A
authors.lastname: Yaghmur
authors.affiliation: Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen , Universitetsparken 2, DK-2100 Copenhagen O, Denmark.
authors.forename: Kolja M
authors.initials: KM
authors.lastname: Knapp
authors.affiliation: Department of Pharmacy, Uppsala University , SE-751 23 Uppsala, Sweden.
authors.forename: Martin
authors.initials: M
authors.lastname: Malmsten
authors.affiliation: Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen , Universitetsparken 2, DK-2100 Copenhagen O, Denmark.
authors.forename: Henrik
authors.initials: H
authors.lastname: Franzyk
authors.affiliation: Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen , Universitetsparken 2, DK-2100 Copenhagen O, Denmark.
authors.forename: Hanne M
authors.initials: HM
authors.lastname: Nielsen
mesh_terms: D045744:Cell Line, Tumor; D057846:Cell-Penetrating Peptides / Q000737:chemistry*; D002788:Cholesterol Esters / Q000737:chemistry; D004337:Drug Carriers / Q000737:chemistry*; D016503:Drug Delivery Systems / Q000379:methods; D020868:Gene Silencing / Q000502:physiology; D006367:HeLa Cells; D006801:Humans; D008051:Lipid Bilayers / Q000737:chemistry / Q000378:metabolism; D008055:Lipids / Q000737:chemistry*; D054878:Lipoylation / Q000502:physiology; D008566:Membranes / Q000737:chemistry* / Q000378:metabolism; D053758:Nanoparticles / Q000737:chemistry; D057786:Peptidomimetics / Q000737:chemistry*; D034444:Peptoids / Q000737:chemistry*; D010714:Phosphatidylethanolamines / Q000737:chemistry; D034741:RNA, Small Interfering / Q000008:administration & dosage / Q000737:chemistry*
chemical_list: D057846:Cell-Penetrating Peptides; D002788:Cholesterol Esters; D004337:Drug Carriers; D008051:Lipid Bilayers; D008055:Lipids; D057786:Peptidomimetics; D034444:Peptoids; D010714:Phosphatidylethanolamines; D034741:RNA, Small Interfering; C094877:dioleoyl phosphatidylethanolamine; C013440:cholesteryl succinate
keywords: SAXS; cell-penetrating peptide; cryo-TEM; drug delivery; nanocarrier; nanomedicine; palmitoylation; peptidomimetic; siRNA delivery