title: Chemical enhancer induced changes in the mechanisms of transdermal delivery of zinc oxide nanoparticles.
abstract: The overlapping wavelength of photoluminescence (PL) of zinc oxide nanoparticles (ZnO NPs) and autofluorescence (AF) from the stratum corneum (SC) has for a long time held back researchers from investigating the chemically enhanced penetration pathways of ZnO NPs into the SC lipids. However, the non-linear polarization effect of second harmonic generation (SHG) may be used for ZnO NPs to be distinguished from the AF of the SC. This study combined the SHG of ZnO NPs and the AF of the SC to image the transdermal delivery of ZnO NPs under the chemical enhancer conditions of oleic acid (OA), ethanol (EtOH) and oleic acid-ethanol (OA-EtOH). In addition to qualitative imaging, the microtransport properties of ZnO NPs were quantified to give the enhancements of the vehicle-to-skin partition coefficient (K), the SHG intensity gradient (G) and the effective diffusion path length (L). The results showed that OA, EtOH and OA-EtOH were all capable of enhancing the transdermal delivery of ZnO NPs by increasing the intercellular lipid fluidity or extracting lipids from the SC.
authors.affiliation: Department of Chemistry, National Taiwan Normal University, Taipei 116, Taiwan.
authors.forename: Tsung-Rong
authors.initials: TR
authors.lastname: Kuo
authors.forename: Chung-Long
authors.initials: CL
authors.lastname: Wu
authors.forename: Chih-Ting
authors.initials: CT
authors.lastname: Hsu
authors.forename: Wen
authors.initials: W
authors.lastname: Lo
authors.forename: Shu-Jen
authors.initials: SJ
authors.lastname: Chiang
authors.forename: Sung-Jan
authors.initials: SJ
authors.lastname: Lin
authors.forename: Chen-Yuan
authors.initials: CY
authors.lastname: Dong
authors.forename: Chia-Chun
authors.initials: CC
authors.lastname: Chen
mesh_terms: D000279:Administration, Cutaneous; D000818:Animals; D002021:Buffers; D003879:Dermatologic Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D004058:Diffusion; D000431:Ethanol / Q000032:analysis; D051379:Mice; D008819:Mice, Nude; D053758:Nanoparticles / Q000032:analysis* / Q000648:ultrastructure; D019301:Oleic Acid / Q000032:analysis; D010316:Particle Size; D012867:Skin / Q000378:metabolism*; D012869:Skin Absorption / Q000502:physiology*; D015034:Zinc Oxide / Q000008:administration & dosage / Q000493:pharmacokinetics*
chemical_list: D002021:Buffers; D003879:Dermatologic Agents; D019301:Oleic Acid; D000431:Ethanol; D015034:Zinc Oxide