title: Hydrodynamic gene delivery in human skin using a hollow microneedle device.
abstract: Microneedle devices have been proposed as a minimally invasive delivery system for the intradermal administration of nucleic acids, both plasmid DNA (pDNA) and siRNA, to treat localised disease or provide vaccination. Different microneedle types and application methods have been investigated in the laboratory, but limited and irreproducible levels of gene expression have proven to be significant challenges to pre-clinical to clinical progression. This study is the first to explore the potential of a hollow microneedle device for the delivery and subsequent expression of pDNA in human skin. The regulatory approved MicronJet600® (MicronJet hereafter) device was used to deliver reporter plasmids (pCMVβ and pEGFP-N1) into viable excised human skin. Exogenous gene expression was subsequently detected at multiple locations that were distant from the injection site but within the confines of the bleb created by the intradermal bolus. The observed levels of gene expression in the tissue are at least comparable to that achieved by the most invasive microneedle application methods e.g. lateral application of a microneedle. Gene expression was predominantly located in the epidermis, although also evident in the papillary dermis. Optical coherence tomography permitted real time visualisation of the sub-surface skin architecture and, unlike a conventional intradermal injection, MicronJet administration of a 50μL bolus appears to create multiple superficial microdisruptions in the papillary dermis and epidermis. These were co-localised with expression of the pCMVβ reporter plasmid. We have therefore shown, for the first time, that a hollow microneedle device can facilitate efficient and reproducible gene expression of exogenous naked pDNA in human skin using volumes that are considered to be standard for intradermal administration, and postulate a hydrodynamic effect as the mechanism of gene delivery.
authors.affiliation: Cardiff School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cathays Park, Cardiff CF10 3NB, UK.
authors.forename: M
authors.initials: M
authors.lastname: Dul
authors.affiliation: Cardiff School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cathays Park, Cardiff CF10 3NB, UK.
authors.forename: M
authors.initials: M
authors.lastname: Stefanidou
authors.affiliation: Cardiff School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cathays Park, Cardiff CF10 3NB, UK.
authors.forename: P
authors.initials: P
authors.lastname: Porta
authors.affiliation: Cardiff School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cathays Park, Cardiff CF10 3NB, UK.
authors.forename: J
authors.initials: J
authors.lastname: Serve
authors.affiliation: Tyndall National Institute, Lee Maltings, University College Cork, Cork, Ireland.
authors.forename: C
authors.initials: C
authors.lastname: O'Mahony
authors.affiliation: Centre d'Immunologie de Marseille-Luminy, Aix Marseille Université, Inserm, CNRS, Marseille, France.
authors.forename: B
authors.initials: B
authors.lastname: Malissen
authors.affiliation: Centre d'Immunologie de Marseille-Luminy, Aix Marseille Université, Inserm, CNRS, Marseille, France.
authors.forename: S
authors.initials: S
authors.lastname: Henri
authors.affiliation: NanoPass Technologies, Israel.
authors.forename: Y
authors.initials: Y
authors.lastname: Levin
authors.affiliation: NanoPass Technologies, Israel.
authors.forename: E
authors.initials: E
authors.lastname: Kochba
authors.affiliation: School of Medicine, Cardiff University, Cardiff, UK.
authors.forename: F S
authors.initials: FS
authors.lastname: Wong
authors.affiliation: School of Medicine, Cardiff University, Cardiff, UK.
authors.forename: C
authors.initials: C
authors.lastname: Dayan
authors.affiliation: Cardiff School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cathays Park, Cardiff CF10 3NB, UK. Electronic address: coulmansa@cardiff.ac.uk.
authors.forename: S A
authors.initials: SA
authors.lastname: Coulman
authors.affiliation: Cardiff School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cathays Park, Cardiff CF10 3NB, UK.
authors.forename: J C
authors.initials: JC
authors.lastname: Birchall
mesh_terms: D000279:Administration, Cutaneous; D018929:Cell Culture Techniques; D002460:Cell Line; D020405:Dermis / Q000378:metabolism; D004817:Epidermis / Q000378:metabolism; D015870:Gene Expression; D018014:Gene Transfer Techniques; D006801:Humans; D057446:Hydrodynamics; D007271:Injections, Intradermal; D008845:Microinjections; D009339:Needles; D034741:RNA, Small Interfering / Q000378:metabolism; D012867:Skin / Q000378:metabolism*; D012869:Skin Absorption; D014018:Tissue Distribution; D014162:Transfection / Q000379:methods
chemical_list: D034741:RNA, Small Interfering
keywords: DNA; Gene therapy; Genetic vaccine; Human skin; Hydrodynamic; Microneedles