Time-Correlated Single Photon Counting For Simultaneous Monitoring Of Zinc Oxide Nanoparticles And NAD(P)H In Intact And Barrier-Disrupted Volunteer Skin

• Published in: Pharmaceutical research Vol. 28; no. 11; pp. 2920 - 2930
• Main Authors: Lin, Lynlee L., Grice, Jeffrey E., Butler, Margaret K., Zvyagin, Andrei V., Becker, Wolfgang, Robertson, Thomas A., Soyer, H. Peter, Roberts, Michael S., Prow, Tarl W.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.11.2011; Springer Nature B.V
• Subjects: Administration, Topical; Biochemistry; Biomedical and Life Sciences; Biomedical Engineering and Bioengineering; Biomedicine; Cosmetics - metabolism; Dermatitis, Atopic - drug therapy; Dermatitis, Atopic - metabolism; Dose-Response Relationship, Drug; Drug Delivery Systems; Humans; Medical Law; Metal Nanoparticles - administration & dosage; Metal Nanoparticles - analysis; Metal Nanoparticles - therapeutic use; NADP - analysis; NADP - metabolism; Nanoparticles; Pharmacology/Toxicology; Pharmacy; Photons; Psoriasis - drug therapy; Psoriasis - metabolism; Research Paper; Skin; Skin - chemistry; Skin - metabolism; Skin Absorption; Sunscreening Agents - administration & dosage; Sunscreening Agents - analysis; Sunscreening Agents - metabolism; Sunscreening Agents - therapeutic use; Surgical Tape; Time Factors; Toxicity Tests - methods; Water Loss, Insensible - physiology; Zinc Oxide - administration & dosage; Zinc Oxide - analysis; Zinc Oxide - metabolism; Zinc Oxide - therapeutic use; Zinc oxides; sunscreen; metabolism; zinc oxide nanoparticle; human skin; multiphoton microscopy
• ISSN: 0724-8741; 1573-904X
• DOI: 10.1007/s11095-011-0515-5

ABSTRACT Purpose There is a lack of relevant, non-animal alternatives for assessing exposure and toxicity of nanoparticle-containing cosmetics, e.g. sunscreens. Our goal was to evaluate timecorrelated single photon counting (TCSPC) for simultaneous monitoring of zinc oxide nanoparticles (ZnO-NP) and the metabolic state of volunteer skin. Methods We separated the fluorescence lifetime signatures of endogenous fluorophore signals (i.e. nicotinamide adenine dinucleotide phosphate, NAD(P)H and keratin) and the ZnO-NP signal using advanced TCSPC to simultaneously determine ZnO-NP penetration profiles and NAD(P)H changes in subjects with altered barrier function, including tape-stripped skin and in psoriasis or atopic dermatitis lesions. Results We detected no ZnO-NP penetration into viable human skin in any group. ZnO-NP signal was significantly increased ( p  < 0.01) on the surface of tape-stripped and lesional skin after 4 and 2 h of treatment, respectively. Free NAD(P)H signal significantly increased in tape-stripped viable epidermis treated for 4 h of ZnO-NP compared to vehicle control. No significant NAD(P)H changes were noted in the lesional study. Conclusion TCSPC techniques enabled simultaneous, real-time quantification of ZnO-NP concentration and NAD(P)H via non-invasive imaging in the stratum corneum and viable epidermis of volunteers.