title: In vivo delivery of functional Flightless I siRNA using layer-by-layer polymer surface modification.
abstract: Gene silencing using small interfering RNA has been proposed as a therapy for cancer, viral infections and other diseases. This study aimed to investigate whether layer-by-layer polymer surface modification could deliver small interfering RNA to decrease fibrotic processes associated with medical device implantation. Anti-green fluorescent protein labelled small interfering RNA was applied to tissue culture plates and polyurethane using a layer-by-layer technique with small interfering RNA and poly-L-lysine. In vitro studies showed that the level of down-regulation of green fluorescent protein was directly related to the number of coatings applied. This layer-by-layer coating technique was then used to generate Rhodamine-Flii small interfering RNA-coated implants for in vivo studies of small interfering RNA delivery via subcutaneous implantation in mice. After two days, Rh-positive cells were observed on the implants' surface indicating cellular uptake of the Rhodamine-Flii small interfering RNA. Decreased Flii gene expression was observed in tissue surrounding the Rhodamine-Flii small interfering RNA coated implants for up to seven days post implantation, returning to baseline by day 21. Genes downstream from Flii, including TGF-β1 and TGF-β3, showed significantly altered expression confirming a functional effect of the Rhodamine-Flii small interfering RNA on gene expression. This research demonstrates proof-of-principle that small interfering RNA can be delivered via layer-by-layer coatings on biomaterials and thereby can alter the fibrotic process.
authors.affiliation: Graduate School of Biomedical Engineering, UNSW Australia, Sydney, Australia p.martens@unsw.edu.au.
authors.forename: Penny J
authors.initials: PJ
authors.lastname: Martens
authors.affiliation: Graduate School of Biomedical Engineering, UNSW Australia, Sydney, Australia Cooperative Research Centre for Polymers, Notting Hill, Australia.
authors.forename: Mai
authors.initials: M
authors.lastname: Ly
authors.affiliation: Regenerative Medicine, Mawson Institute, University of South Australia, South Australia, Australia.
authors.forename: Damian H
authors.initials: DH
authors.lastname: Adams
authors.affiliation: Graduate School of Biomedical Engineering, UNSW Australia, Sydney, Australia Cooperative Research Centre for Polymers, Notting Hill, Australia.
authors.forename: Kathryn R
authors.initials: KR
authors.lastname: Penzkover
authors.affiliation: Regenerative Medicine, Mawson Institute, University of South Australia, South Australia, Australia.
authors.forename: Xanthe
authors.initials: X
authors.lastname: Strudwick
authors.affiliation: Regenerative Medicine, Mawson Institute, University of South Australia, South Australia, Australia.
authors.forename: Allison J
authors.initials: AJ
authors.lastname: Cowin
authors.affiliation: Graduate School of Biomedical Engineering, UNSW Australia, Sydney, Australia Cooperative Research Centre for Polymers, Notting Hill, Australia.
authors.forename: Laura A
authors.initials: LA
authors.lastname: Poole-Warren
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D002352:Carrier Proteins; D002460:Cell Line; D003598:Cytoskeletal Proteins / Q000235:genetics*; D051379:Mice; D008807:Mice, Inbred BALB C; D008840:Microfilament Proteins; D041681:NIH 3T3 Cells; D011108:Polymers / Q000737:chemistry*; D034741:RNA, Small Interfering / Q000008:administration & dosage*; D013499:Surface Properties; D015534:Trans-Activators
chemical_list: D001672:Biocompatible Materials; D002352:Carrier Proteins; D003598:Cytoskeletal Proteins; C000609263:FlII protein, mouse; D008840:Microfilament Proteins; D011108:Polymers; D034741:RNA, Small Interfering; D015534:Trans-Activators
keywords: Animal model; drug delivery; polyurethane; siRNA