title: Differential nanotoxicological and neuroinflammatory liabilities of non-viral vectors for RNA interference in the central nervous system.
abstract: Progression of RNA interference-based gene silencing technologies for the treatment of disorders of the central nervous system (CNS) depends on the availability of efficient non-toxic nanocarriers. Despite advances in the field of nanotechnology undesired and non-specific interactions with different brain-cell types occur and are poorly investigated. To this end, we studied the cytotoxic and neuroinflammatory effects of widely-used transfection reagents and modified amphiphilic β-cyclodextrins (CDs). All non-viral vectors formed positively charged nanoparticles with distinctive physicochemical properties. Differential and significant cytotoxic effects were observed among commercially available cationic vectors, whereas CDs induced limited disruptions of cellular membrane integrity and mitochondrial dehydrogenase activity. Interestingly, murine derived BV2 microglia cells and a rat striatal in vitro model of Huntington's disease (ST14A-HTT120Q) were more susceptible to toxicity than human U87 astroglioma cells. BV2 microglia presented significant increases in cytokine, toll-like receptor 2 and cyclooxygenase-2 gene expression after transfection with selected commercial vectors but not with CD.siRNA nanoparticles. Non-viral siRNA nanoparticles formulated with G6 polyamidoamine (PAMAM) also significantly increased cytokine gene expression in the brain following injections into the mouse striatum. Together our data identify modified CDs as nanosystems that enable siRNA delivery to the brain with low levels of cytotoxicity and immunological activation.
authors.affiliation: Pharmacodelivery Group, School of Pharmacy, University College Cork, Cork, Ireland; Dept. Anatomy and Neuroscience, University College Cork, Cork, Ireland.
authors.forename: Bruno M D C
authors.initials: BM
authors.lastname: Godinho
authors.forename: David J
authors.initials: DJ
authors.lastname: McCarthy
authors.forename: Cristina
authors.initials: C
authors.lastname: Torres-Fuentes
authors.forename: Caroll J
authors.initials: CJ
authors.lastname: Beltrán
authors.forename: Joanna
authors.initials: J
authors.lastname: McCarthy
authors.forename: Aoife
authors.initials: A
authors.lastname: Quinlan
authors.forename: Julien R
authors.initials: JR
authors.lastname: Ogier
authors.forename: Raphael
authors.initials: R
authors.lastname: Darcy
authors.forename: Caitriona M
authors.initials: CM
authors.lastname: O'Driscoll
authors.forename: John F
authors.initials: JF
authors.lastname: Cryan
mesh_terms: D000818:Animals; D001483:Base Sequence; D045744:Cell Line, Tumor; D003342:Corpus Striatum / Q000187:drug effects*; D005822:Genetic Vectors; D006801:Humans; D007249:Inflammation / Q000139:chemically induced*; D051379:Mice; D017628:Microglia / Q000166:cytology / Q000187:drug effects*; D053758:Nanoparticles / Q000633:toxicity*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D051381:Rats
chemical_list: D034741:RNA, Small Interfering
keywords: Cyclodextrins; Cytokines; High content analysis; Stereotaxic; Toll-like receptors; siRNA