BME PhD Defense: Luke J. Mortensen

Analysis of Quantum Dot Skin Penetration in a Barrier Compromised In Vivo Model

Supervised by Professor Lisa DeLouise

Abstract

Exposure to engineered nanoparticles (NPs) is becoming near-inescapable as their unique size dependent properties have ensured integration into a wide range of consumer products and research tools. One of the most biologically impactful of these applications is in consumer products such as sunscreens and other cosmetics, where consumer use commonly consists of topical application to UVB damaged skin. A number of studies have investigated the ability of NPs to penetrate the skin barrier, but very few are available on NP permeation differences that result from clinically relevant skin barrier disruptions such as UVB. We use semiconductor quantum dots (QDs) as a model nanoparticle to investigate the impact of UVB on skin permeability. QDs are NPs with advantageous fluorescence properties including high quantum yield, broad excitability, and narrow emission bandwidth. This work presents the first quantitative study to evaluate the impact of UVB on skin penetration of QDs and primary keratinocyte interaction with QDs, and has advanced technology for whole tissue confocal microscopic evaluation of QD skin penetration. Important advancements have been made, suggesting that UVB may increase risk of systemic exposure to NPs, and that the lymphatic system may play an important role in the translocation of topically applied NPs.