Impact of Cosmetic Lotions on Nanoparticle Penetration through ex vivo C57BL/6 Hairless Mouse and Human Skin: A Comparison Study.

Alice Pentland,Lisa DeLouise,Samreen Jatana,Linda Callahan

doi:10.3390/cosmetics3010006

Alice Pentland, Lisa DeLouise + Show 2 more

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https://doi.org/10.3390/cosmetics3010006

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Abstract

Understanding the interactions of nanoparticles (NPs) with skin is important from a consumer and occupational health and safety perspective, as well as for the design of effective NP-based transdermal therapeutics. Despite intense efforts to elucidate the conditions that permit NP penetration, there remains a lack of translatable results from animal models to human skin. The objectives of this study are to investigate the impact of common skin lotions on NP penetration and to quantify penetration differences of quantum dot (QD) NPs between freshly excised human and mouse skin. QDs were mixed in 7 different vehicles, including 5 commercial skin lotions. These were topically applied to skin using two exposure methods; a petri dish protocol and a Franz diffusion cell protocol. QD presence in the skin was quantified using Confocal Laser Scanning Microscopy. Results show that the commercial vehicles can significantly impact QD penetration in both mouse and human skin. Lotions that contain alpha hydroxyl acids (AHA) facilitated NP penetration. Lower QD signal was observed in skin studied using a Franz cell. Freshly excised human skin was also studied immediately after the sub-cutaneous fat removal process, then after 24 hours rest ex vivo. Resting human skin 24 hours prior to QD exposure significantly reduced epidermal presence. This study exemplifies how application vehicles, skin processing and the exposure protocol can affect QD penetration results and the conclusions that maybe drawn between skin models.

Highlights

The expanding commercialization of products that contain engineered nanoparticles (NPs) has generated vast interest among researchers in the nanotoxicology field to better understand their fate and transport in biological systems [1–4]
Different vehicles including five commercial skin lotions (Supplementary Data Table S1), glycerol residual vehicle was wiped off using Q-tips and the samples were processed for Confocal Laser Scanning Microscopy (CLSM)
We demonstrated that quantum dot (QD) penetration through rested human skin decreased to levels that measured in mouse skin (Eucerin smoothing lotion and water test groups) that was not subjected to the fat removal process thereby confirming that the C57BL/6 hairless mouse skin is a useful model for investigating

Summary

Introduction

The expanding commercialization of products that contain engineered nanoparticles (NPs) has generated vast interest among researchers in the nanotoxicology field to better understand their fate and transport in biological systems [1–4]. The increasing presence of metal oxide NPs in daily wear ultra-violet radiation (UVR) protective cosmetic products has driven considerable effort to understand the conditions that may permit TiO2 and ZnO NPs to penetrate the skin barrier [8,9]. Various in vivo as well as ex vivo skin models (rat, mouse, pig and human) have been used to examine the effects of NP physiochemical properties (e.g., size, composition, charge) and exogenous factors Cosmetics 2016, 3, 6 dermabrasion, tape stripping, flexion, chemical agents) on NP skin penetration, systemic translocation and toxicity [5,10–23]. Studies consistently report that healthy skin is a formidable barrier to NP penetration. Higher levels of penetration are generally observed through barrier-impaired skin [7,24]

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