title: Quantum dot penetration into viable human skin.
abstract: Systematic studies probing the effects of nanoparticle surface modification and formulation pH are important in nanotoxicology and nanomedicine. In this study, we use laser-scanning fluorescence confocal microscopy to evaluate nanoparticle penetration in viable excised human skin that was intact or tape-stripped. Quantum dot (QD) fluorescent nanoparticles with three surface modifications: Polyethylene glycol (PEG), PEG-amine (PEG-NH₂) and PEG-carboxyl (PEG-COOH) were evaluated for human skin penetration from aqueous solutions at pH 7.0 and at pHs of solutions provided by the QD manufacturer: 8.3 (PEG, PEG-NH₂) and 9.0 (PEG-COOH). There was some penetration into intact viable epidermis of skin for the PEG-QD at pH 8.3, but not at pH 7.0 nor for any other QD at the pHs used. Upon tape stripping 30 strips of stratum corneum, all QDs penetrated through the viable epidermis and into the upper dermis within 24 h.
authors: Therapeutics Research Centre, School of Medicine, Princess Alexandra Hospital, The University of Queensland, Brisbane, Queensland, Australia.
authors: Tarl W
authors: TW
authors: Prow
authors: Nancy A
authors: NA
authors: Monteiro-Riviere
authors: Alfred O
authors: AO
authors: Inman
authors: Jeffrey E
authors: JE
authors: Grice
authors: Xianfeng
authors: X
authors: Chen
authors: Xin
authors: X
authors: Zhao
authors: Washington H
authors: WH
authors: Sanchez
authors: Audrey
authors: A
authors: Gierden
authors: Mark A F
authors: MA
authors: Kendall
authors: Andrei V
authors: AV
authors: Zvyagin
authors: Detlev
authors: D
authors: Erdmann
authors: Jim E
authors: JE
authors: Riviere
authors: Michael S
authors: MS
authors: Roberts
mesh_terms: D015194:Diffusion Chambers, Culture; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D018613:Microscopy, Confocal; D053758:Nanoparticles; D010316:Particle Size; D011092:Polyethylene Glycols / Q000378:metabolism / Q000494:pharmacology; D045663:Quantum Dots; D012867:Skin / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D012869:Skin Absorption / Q000187:drug effects; D046509:Tissue Culture Techniques
chemical_list: D011092:Polyethylene Glycols