title: Lipid-based nanotherapeutics for siRNA delivery.
abstract: RNA interference (RNAi) is a specific gene-silencing mechanism triggered by small interfering RNA (siRNA). The application of RNAi in the clinic requires the development of safe and effective delivery systems. Inspired by progress with lipid-based systems in drug delivery, efforts have been dedicated to the development of liposomal siRNA delivery systems. Many of the lipid-based delivery vehicles self-assemble with siRNA through electrostatic interactions with charged amines, generating multi-lamellar lipoplexes with positively charged lipid bilayers separated from one another by sheets of negatively charged siRNA strands. Internalization of lipid-based siRNA delivery systems into cells typically occurs through endocytosis; accordingly, delivery requires materials that can facilitate endosomal escape. The size of the carrier is important as carriers <100 nm in diameter have been reported to have higher accumulation levels in tumours, hepatocytes and inflamed tissue, whereas larger particles tend to be taken up by Kupffer cells or other components of the reticuloendothelial system (RES). To reduce RES uptake and increase circulation time, carriers have been modified on the surface with hydrophilic materials, such as polyethyleneglycol. Herein, we review the molecular and structural parameters of lipid-based siRNA delivery systems.
authors.affiliation: Department of Chemical Engineering and David H. Koch Institute of Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA.
authors.forename: A
authors.initials: A
authors.lastname: Schroeder
authors.forename: C G
authors.initials: CG
authors.lastname: Levins
authors.forename: C
authors.initials: C
authors.lastname: Cortez
authors.forename: R
authors.initials: R
authors.lastname: Langer
authors.forename: D G
authors.initials: DG
authors.lastname: Anderson
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002784:Cholesterol / Q000008:administration & dosage / Q000493:pharmacokinetics; D004337:Drug Carriers / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics; D004705:Endocytosis; D011992:Endosomes; D006801:Humans; D008055:Lipids / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics; D051379:Mice; D053769:Nanocapsules / Q000008:administration & dosage / Q000737:chemistry; D050997:Nanomedicine / Q000379:methods; D034741:RNA, Small Interfering / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics
chemical_list: D004337:Drug Carriers; D008055:Lipids; D053769:Nanocapsules; D034741:RNA, Small Interfering; D002784:Cholesterol