title: Efficient delivery of siRNA to cortical neurons using layered double hydroxide nanoparticles.
abstract: Small interfering RNAs (siRNAs) are capable of targeting and destroying specific mRNAs, making them particularly suited to the treatment of neurodegenerative conditions such as Huntington's Disease where the production of abnormal proteins results in a gain-of-function phenotype. Although a variety of nanoparticle formulations are currently under development as siRNA delivery systems, application of these technologies has been limited by their high cytotoxicity, low drug loading capacity and release, and inability to penetrate cell membranes. Layered double hydroxide (LDH) nanoparticles are now emerging as a potential new drug delivery system as they exhibit low cytotoxicity and are highly biocompatible. Here we present the first study investigating LDH delivery of siRNAs to primary cultured neurons. We show that internalization by neurons is rapid, dose-dependent and saturable, and markedly more efficient than in other cell types. We demonstrate that siRNA-LDH complexes are internalized by clathrin-dependent endocytosis at the cell body and in neurites, with subsequent retrograde transport to the cell body followed by efficient release into the cytoplasm. Finally we show that LDH mediated siRNA delivery effectively silences neuronal gene expression. This study therefore confirms the potential of LDH nanoparticles as a drug delivery system for patients suffering from neurodegenerative disease.
authors: ARC Centre of Excellence for Functional Nanomaterials, The University of Queensland, Queensland 4072, Australia.
authors: Yunyi
authors: Y
authors: Wong
authors: Kathryn
authors: K
authors: Markham
authors: Zhi Ping
authors: ZP
authors: Xu
authors: Min
authors: M
authors: Chen
authors: Gao Qing
authors: GQ
authors: Max Lu
authors: Perry F
authors: PF
authors: Bartlett
authors: Helen M
authors: HM
authors: Cooper
mesh_terms: D017607:Aluminum Compounds / Q000737:chemistry*; D000818:Animals; D001369:Axons / Q000378:metabolism; D002470:Cell Survival; D002540:Cerebral Cortex / Q000166:cytology*; D002966:Clathrin / Q000378:metabolism; D004705:Endocytosis; D005347:Fibroblasts / Q000378:metabolism; D055785:Gene Knockdown Techniques; D020868:Gene Silencing; D018014:Gene Transfer Techniques; D006801:Humans; D006878:Hydroxides / Q000737:chemistry*; D017616:Magnesium Compounds / Q000737:chemistry*; D051379:Mice; D008810:Mice, Inbred C57BL; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D009474:Neurons / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D034741:RNA, Small Interfering / Q000378:metabolism*
chemical_list: D017607:Aluminum Compounds; D002966:Clathrin; D006878:Hydroxides; D017616:Magnesium Compounds; D034741:RNA, Small Interfering