title: Controlling HBV replication in vivo by intravenous administration of triggered PEGylated siRNA-nanoparticles.
abstract: Harnessing RNA interference (RNAi) to inhibit hepatitis B virus (HBV) gene expression has promising application to therapy. Here we describe a new hepatotropic nontoxic lipid-based vector system that is used to deliver chemically unmodified small interfering RNA (siRNA) sequences to the liver. Anti HBV formulations were generated by condensation of siRNA (A component) with cationic liposomes (B component) to form AB core particles. These core particles incorporate an aminoxy cholesteryl lipid for convenient surface postcoupling of polyethylene glycol (PEG; C component, stealth/biocompatibility polymer) to give triggered PEGylated siRNA-nanoparticles (also known as siRNA-ABC nanoparticles) with uniform small sizes of 80-100 nm in diameter. The oxime linkage that results from PEG coupling is pH sensitive and was included to facilitate acidic pH-triggered release of nucleic acids from endosomes. Nanoparticle-mediated siRNA delivery results in HBV replication knockdown in cell culture and in murine hydrodynamic injection models in vivo. Furthermore repeated systemic administration of triggered PEGylated siRNA-nanoparticles to HBV transgenic mice results in the suppression of markers of HBV replication by up to 3-fold relative to controls over a 28 day period. This compares favorably to silencing effects seen during lamivudine treatment. Collectively these observations indicate that our PEGylated siRNA-nanoparticles may have valuable applications in RNAi-based HBV therapy.
authors.affiliation: Department of Molecular Medicine and Haematology, University of the Witwatersrand Medical School, WITS 2050, South Africa.
authors.forename: Sergio
authors.initials: S
authors.lastname: Carmona
authors.forename: Michael R
authors.initials: MR
authors.lastname: Jorgensen
authors.forename: Soumia
authors.initials: S
authors.lastname: Kolli
authors.forename: Carol
authors.initials: C
authors.lastname: Crowther
authors.forename: Felix H
authors.initials: FH
authors.lastname: Salazar
authors.forename: Patricia L
authors.initials: PL
authors.lastname: Marion
authors.forename: Masato
authors.initials: M
authors.lastname: Fujino
authors.forename: Yukikazu
authors.initials: Y
authors.lastname: Natori
authors.forename: Maya
authors.initials: M
authors.lastname: Thanou
authors.forename: Patrick
authors.initials: P
authors.lastname: Arbuthnot
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Miller
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D006515:Hepatitis B virus / Q000235:genetics* / Q000502:physiology*; D006801:Humans; D007275:Injections, Intravenous; D008081:Liposomes / Q000737:chemistry; D051379:Mice; D015394:Molecular Structure; D053758:Nanoparticles / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D034741:RNA, Small Interfering / Q000008:administration & dosage / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D014779:Virus Replication / Q000235:genetics / Q000502:physiology*
chemical_list: D008081:Liposomes; D034741:RNA, Small Interfering; D011092:Polyethylene Glycols