Effect of flexing and massage on in vivo human skin penetration and toxicity of zinc oxide nanoparticles.
We assessed the effects of flexing and massage on human skin penetration and toxicity of topically applied coated and uncoated zinc oxide nanoparticles (˜75 nm) in vivo.



Noninvasive multiphoton tomography with fluorescence lifetime imaging was used to evaluate the penetration of nanoparticles through the skin barrier and cellular apoptosis in the viable epidermis.



All nanoparticles applied to skin with flexing and massage were retained in the stratum corneum or skin furrows. No significant penetration into the viable epidermis was seen and no cellular toxicity was detected.



Exposure of normal in vivo human skin to these nanoparticles under common in-use conditions of flexing or massage is not associated with significant adverse events.
Therapeutics Research Centre, School of Medicine, The University of Queensland, Translational Research Institute, Woolloongabba, QLD, Australia.|Instituto de Ciências Ambientais Químicas e Farmacêuticas, Universidade Federal de São Paulo, Diadema SP, Brazil.
Vânia R
VR
Leite-Silva
Therapeutics Research Centre, School of Medicine, The University of Queensland, Translational Research Institute, Woolloongabba, QLD, Australia.
David C
DC
Liu
Therapeutics Research Centre, School of Medicine, The University of Queensland, Translational Research Institute, Woolloongabba, QLD, Australia.
Washington Y
WY
Sanchez
School of Pharmacy & Medical Sciences, University of South Australia City East Campus, Adelaide, SA, Australia.
Hauke
H
Studier
Therapeutics Research Centre, School of Medicine, The University of Queensland, Translational Research Institute, Woolloongabba, QLD, Australia.
Yousuf H
YH
Mohammed
School of Pharmacy & Medical Sciences, University of South Australia City East Campus, Adelaide, SA, Australia.
Amy
A
Holmes
Becker & Hickl GmbH, Nahmitzer Damm 30, 12277 Berlin, Germany.
Wolfgang
W
Becker
Therapeutics Research Centre, School of Medicine, The University of Queensland, Translational Research Institute, Woolloongabba, QLD, Australia.
Jeffrey E
JE
Grice
School of Pharmacy, CHIRI, Curtin University of Technology, Perth, WA, Australia.
Heather Ae
HA
Benson
Therapeutics Research Centre, School of Medicine, The University of Queensland, Translational Research Institute, Woolloongabba, QLD, Australia.|School of Pharmacy & Medical Sciences, University of South Australia City East Campus, Adelaide, SA, Australia.
Michael S
MS
Roberts
D000328:Adult; D017209:Apoptosis / Q000187:drug effects; D006801:Humans; D008405:Massage; D012867:Skin / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D012869:Skin Absorption; D013473:Sunscreening Agents / Q000493:pharmacokinetics* / Q000633:toxicity*; D055815:Young Adult; D015034:Zinc Oxide / Q000493:pharmacokinetics* / Q000633:toxicity*
D013473:Sunscreening Agents; D015034:Zinc Oxide
flexing; human skin in vivo; imaging; massage; nanoparticle penetration; zinc oxide