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

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.

Emergence of Nanoplastic in the Environment and Possible Impact on Human Health

“…Their findings suggest that certain ingredients (e.g., urea, glycerol, and α-hydroxyl acids) found in common commercial skin care lotions can enhance NP penetration into the skin. 145 In addition, several chemical penetration enhancers have shown their potential to support skin penetration by nanoparticles. 146 Kuo et al illustrated the differences between oleic acid, ethanol, and oleic acid−ethanol enhancers for the transport of zinc oxide nanoparticles.…”

Exploring the potential for rosacea therapeutics of siRNA dispersion in topical emulsions

“…Mechanisms for urea‐dependent skin permeability enhancement were previously discussed; for example, in the works Albèr et al and Björklund et al described the enhancement of skin permeability mediated by urea, as effect of ultrastructural changes . Furthermore, Jatana et al suggested that commonly used active ingredients, such as urea and glycerol, could highly affect the skin penetration of particulates, and thus, it could possibly results in the cutaneous deposition of water‐soluble macromolecules up to a size of few nanometres . According to these studies, systemic permeation of the macromolecular drug is unlikely and the chemistry structure of the siRNA used does not make it particularly suitable as a long circulating system.…”

Skin care products can aggravate epidermal function: studies in a murine model suggest a pathogenic role in sensitive skin

“…We have shown here that both vehicles and branded skin care products can induce severe adverse reactions in normal mouse skin, which is much thinner (∼ 15 μm) (56) and more permeable (20,21) than human skin (∼ 75-96 μm) (57), making it more susceptible to stimuli than normal human skin. Therefore, depending on regulatory issues related to the testing of such products in animals, mouse skin could serve as a useful model with which to evaluate the safety of over-the-counter skin care products and cosmetics.…”

“…Although skin care products can cause few or no adverse reactions in normal human skin, they could still provoke cutaneous symptoms in subjects with sensitive skin. Accordingly, in the present study, we assessed the impact of several vehicles and branded skin care products on epidermal functions in normal mice, whose skin is more permeable than human skin . This model could serve as a useful analogue of sensitive skin in humans.…”