title: Solid nano-in-nanoparticles for potential delivery of siRNA.
abstract: siRNA-based therapeutics possess great potential to treat a wide variety of genetic disorders. However, they suffer from low cellular uptake and short half-lives in blood circulation; issues that remain to be addressed. This work is, to the best of our knowledge, the first to report the production of solid nano-in-nanoparticles, termed double nano carriers (DNCs) by means of the innovative technology of nano spray drying. DNCs (with a median size of 580-770nm) were produced by spraying at low temperatures (50°C) to prevent damage to heat-sensitive biomacromolecules like siRNA. DNCs consisting of Poly (d,l-lactide-co-glycolide) used as a wall material, encapsulating 20% human serum albumin primary nanoparticles (PNPs) loaded with siRNA, were obtained as a dry nanoparticulate powder with smooth spherical surfaces and a unique inner morphology. Incubation of pegylated or non-pegylated DNCs under sink conditions at 37°C, elicited a controlled release profile of the siRNA for up to 12 or 24h, respectively, with a minimal burst effect. Prolonged incubation of pegylated DNCs loaded with active siRNA (anti EGFR) in an A549 epithelial cell culture monolayer did not induce any apparent cytotoxicity. A slow degradation of the internalized DNCs by the cells was also observed resulting in the progressive release of the siRNA for up to 6days, as corroborated by laser confocal microscopy. The structural integrity and silencing activity of the double encapsulated siRNA were fully preserved, as demonstrated by HPLC, gel electrophoresis, and potent RNAi activity of siRNA extracted from DNCs. These results demonstrate the potential use of DNCs as a nano drug delivery system for systemic administration and controlled release of siRNA and potentially other sensitive bioactive macromolecules.
authors.affiliation: The Institute for Drug Research of the School of Pharmacy, Faculty of Medicine, The Hebrew University, Jerusalem, Israel.
authors.forename: Orit
authors.initials: O
authors.lastname: Amsalem
authors.affiliation: The Institute for Drug Research of the School of Pharmacy, Faculty of Medicine, The Hebrew University, Jerusalem, Israel.
authors.forename: Taher
authors.initials: T
authors.lastname: Nassar
authors.affiliation: The Institute for Drug Research of the School of Pharmacy, Faculty of Medicine, The Hebrew University, Jerusalem, Israel.
authors.forename: Sandrine
authors.initials: S
authors.lastname: Benhamron
authors.affiliation: The Institute for Drug Research of the School of Pharmacy, Faculty of Medicine, The Hebrew University, Jerusalem, Israel.
authors.forename: Philip
authors.initials: P
authors.lastname: Lazarovici
authors.affiliation: The Institute for Drug Research of the School of Pharmacy, Faculty of Medicine, The Hebrew University, Jerusalem, Israel. Electronic address: simonb@ekmd.huji.ac.il.
authors.forename: Simon
authors.initials: S
authors.lastname: Benita
authors.affiliation: The Institute for Drug Research of the School of Pharmacy, Faculty of Medicine, The Hebrew University, Jerusalem, Israel.
authors.forename: Eylon
authors.initials: E
authors.lastname: Yavin
mesh_terms: D000072283:A549 Cells; D003890:Desiccation / Q000379:methods; D066246:ErbB Receptors / Q000235:genetics; D018014:Gene Transfer Techniques; D006801:Humans; D019344:Lactic Acid / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000379:methods; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000008:administration & dosage* / Q000235:genetics; D000067492:RNAi Therapeutics; D014162:Transfection / Q000379:methods*
chemical_list: D034741:RNA, Small Interfering; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; C512478:EGFR protein, human; D066246:ErbB Receptors
keywords: Controlled release; Double encapsulation; Nanocarriers; siRNA