Background free imaging of upconversion nanoparticle distribution in human skin

Zhen Song*, Yuri G. Anissimov, Jiangbo Zhao, Andrei V. Nechaev, Annemarie Nadort, Dayong Jin, Tarl W. Prow, Michael S. Roberts, Andrei V. Zvyagin

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

38 Citations (Scopus)
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Widespread applications of nanotechnology materials have raised safety concerns due to their possible penetration through skin and concomitant uptake in the organism. This calls for systematic study of nanoparticle transport kinetics in skin, where high-resolution optical imaging approaches are often preferred. We report on application of emerging luminescence nanomaterial, called upconversion nanoparticles (UCNPs), to optical imaging in skin that results in complete suppression of background due to the excitation light back-scattering and biological tissue autofluorescence. Freshly excised intact and microneedle-treated human skin samples were topically coated with oil formulation of UCNPs and optically imaged. In the first case, 8-and 32-nm UCNPs stayed at the topmost layer of the intact skin, stratum corneum. In the second case, 8-nm nanoparticles were found localized at indentations made by the microneedle spreading in dermis very slowly (estimated diffusion coefficient, Dnp=3-7×10-12 cm2·s-1). The maximum possible UCNP-imaging contrast was attained by suppressing the background level to that of the electronic noise, which was estimated to be superior in comparison with the existing optical labels.

Original languageEnglish
Article number61215
Pages (from-to)1-10
Number of pages10
JournalJournal of Biomedical Optics
Issue number6
Publication statusPublished - 2013


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