title: Exosome-mediated delivery of siRNA in vitro and in vivo.
abstract: The use of small interfering RNAs (siRNAs) to induce gene silencing has opened a new avenue in drug discovery. However, their therapeutic potential is hampered by inadequate tissue-specific delivery. Exosomes are promising tools for drug delivery across different biological barriers. Here we show how exosomes derived from cultured cells can be harnessed for delivery of siRNA in vitro and in vivo. This protocol first describes the generation of targeted exosomes through transfection of an expression vector, comprising an exosomal protein fused with a peptide ligand. Next, we explain how to purify and characterize exosomes from transfected cell supernatant. Next, we detail crucial steps for loading siRNA into exosomes. Finally, we outline how to use exosomes to efficiently deliver siRNA in vitro and in vivo in mouse brain. Examples of anticipated results in which exosome-mediated siRNA delivery is evaluated by functional assays and imaging are also provided. The entire protocol takes ~3 weeks.
authors.affiliation: Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK.
authors.forename: Samir
authors.initials: S
authors.lastname: El-Andaloussi
authors.forename: Yi
authors.initials: Y
authors.lastname: Lee
authors.forename: Samira
authors.initials: S
authors.lastname: Lakhal-Littleton
authors.forename: Jinghuan
authors.initials: J
authors.lastname: Li
authors.forename: Yiqi
authors.initials: Y
authors.lastname: Seow
authors.forename: Chris
authors.initials: C
authors.lastname: Gardiner
authors.forename: Lydia
authors.initials: L
authors.lastname: Alvarez-Erviti
authors.forename: Ian L
authors.initials: IL
authors.lastname: Sargent
authors.forename: Matthew J A
authors.initials: MJ
authors.lastname: Wood
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism; D055354:Exosomes / Q000235:genetics*; D020868:Gene Silencing; D018014:Gene Transfer Techniques; D005822:Genetic Vectors; D051379:Mice; D034741:RNA, Small Interfering / Q000008:administration & dosage* / Q000235:genetics; D014162:Transfection / Q000379:methods
chemical_list: D034741:RNA, Small Interfering