Cerium Oxide Nanoparticles Absorption through Intact and Damaged Human Skin

Area of Science:

• Environmental science
• Materials science
• Toxicology

Background:

• Cerium oxide (CeO2) nanoparticles (NPs) have widespread industrial and biomedical applications.
• Previous research indicates potential systemic toxicity and bioaccumulation following inhalation exposure.
• Data regarding transdermal absorption and skin permeation of CeO2 NPs are limited.

Purpose of the Study:

• To investigate the in vitro dermal absorption and transdermal permeation of 17-nm CeO2 NPs through human skin.
• To compare NP penetration in intact versus abraded skin models.

Main Methods:

• Utilized excised human skin mounted on Franz diffusion cells.
• Dispersed 17-nm CeO2 NPs in synthetic sweat at a concentration of 1 g L-1.
• Exposed both intact and needle-abraded skin samples to the NP dispersion for 24 hours.
• Quantified cerium content in skin layers and receiving solutions using appropriate analytical techniques.

Main Results:

• Significantly higher cerium deposition in abraded skin (7.07 ± 0.78 µg cm-2) compared to intact skin (3.64 ± 0.15 µg cm-2).
• Low concentrations of cerium detected in the receiving solution for both intact (2.0 ± 0.4 ng cm-2) and abraded skin (3.3 ± 0.7 ng cm-2) after 24 hours.
• Cerium content within the dermal layers was substantially higher in abraded skin (2.93 ± 0.71 µg cm-2) than in intact skin (0.39 ± 0.16 µg cm-2).

Conclusions:

• Cerium oxide nanoparticle dermal absorption and transdermal permeation are minimal.
• Skin integrity significantly influences cerium uptake, with abrasion increasing deposition.
• Provides initial evidence of potential, albeit low, cerium skin uptake from CeO2 NP exposure.