title: Drug delivery into microneedle-porated nails from nanoparticle reservoirs.
abstract: This study demonstrates the potential of polymeric nanoparticles as drug reservoirs for sustained topical drug delivery into microneedle-treated human nail. Laser scanning confocal microscopy was used to image the delivery of a fluorescent model compound from nanoparticles into the nail. A label-free imaging technique, stimulated Raman scattering microscopy, was applied, in conjunction with two-photon fluorescence imaging, to probe the disposition of nanoparticles and an associated lipophilic 'active' in a microneedle-porated nail. The results provide clear evidence that the nanoparticles function as immobile reservoirs, sequestered on the nail surface and in the microneedle-generated pores, from which the active payload can be released and diffuse laterally into the nail over an extended period of time.
authors.affiliation: Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK.
authors.forename: Wing Sin
authors.initials: WS
authors.lastname: Chiu
authors.affiliation: Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK.
authors.forename: Natalie A
authors.initials: NA
authors.lastname: Belsey
authors.affiliation: Department of Physics & Medical Imaging, University of Exeter, Exeter EX4 4QL, UK.
authors.forename: Natalie L
authors.initials: NL
authors.lastname: Garrett
authors.affiliation: Department of Physics & Medical Imaging, University of Exeter, Exeter EX4 4QL, UK.
authors.forename: Julian
authors.initials: J
authors.lastname: Moger
authors.affiliation: Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK.
authors.forename: Gareth J
authors.initials: GJ
authors.lastname: Price
authors.affiliation: Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK.
authors.forename: M Begoña
authors.initials: MB
authors.lastname: Delgado-Charro
authors.affiliation: Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK. Electronic address: r.h.guy@bath.ac.uk.
authors.forename: Richard H
authors.initials: RH
authors.lastname: Guy
mesh_terms: D016503:Drug Delivery Systems; D006801:Humans; D018613:Microscopy, Confocal; D009262:Nails / Q000378:metabolism*; D053758:Nanoparticles / Q000737:chemistry*; D010078:Oxazines / Q000737:chemistry; D011091:Polyesters / Q000737:chemistry; D012995:Solubility; D013059:Spectrum Analysis, Raman
chemical_list: D010078:Oxazines; D011091:Polyesters; C016240:polycaprolactone; C044808:nile red
keywords: Drug delivery; Microneedle poration; Nail; Nanoparticles; Stimulated Raman scattering