755 The risk of inflammation and fibrosis in the skin microenvironment through skin penetration by nanoplastics

Environmental microplastics exist at sub-micrometer sizes (nanoplastics, NPs) as they continue to disintegrate over time. Although concerns regarding harm human health are growing, data on the effects of NPs skin lacking. Therefore, this study sought investigate whether penetrate and affect physiology cells Different sized polystyrene (0.2, 0.5, 1.0 μm) (approximately sub-micron level) tagged with fluorescence were applied mouse models barrier disrupted (oxazolone-induced atopic dermatitis like, tape-stripping model) constituent cell culture (human keratinocyte, dermal fibroblast, THP-1-derived macrophage). Penetration was then evaluated using fluorescent microscopy. Both mRNA protein expressions factors related lipids, differentiation, collagen synthesis, primary inflammation measured by qRT-PCR western blotting, respectively. Additionally, possibility cellular transformation cell-to-cell transfer during passage check for further hazardous effects. Unlike normal skin, observed inside epidermis upper dermis in inflammatory conditions taper stripped skin. In addition, could be internalized within 9, 24, 6 hours keratinocytes, HDFs macrophages, respectively, remained intracellularly even after 2 cultures. Abnormalities differentiation markers keratinocytes increases cytokines, fibroblast fibrosis-inducing including TGF-β found. synthesis fibroblasts increased. There no specific findings assay each type. Submicron-sized (NPs) damaged stratum corneum reach dermis. Here, increase cytokines macrophages induce fibrosis stimulation.