Assessment of skin sensitization potential of manganese oxide and copper oxide nanoparticles through the local lymph node assay: 5-Bromo-deoxyuridine flow cytometry method

다국어 초록 (Multilingual Abstract)

Nanoparticles (NPs), fine particles ranging from 1 to 100 nm, are being used extensively in various fields including industry, agriculture, engineering. Nanoparticles also have become the imperative parts of cosmetic and dermal products owing to the higher benefits over their counter bulk particles. Manganese oxide (Mn2O3) and copper oxide (CuO) are used in cosmetics and dermal products owing to their UV protection and antimicrobial properties and also to make products transparent and aesthetically acceptable. Although Mn2O3 and CuO are used in consumer products that get exposed to the skin, their skin sensitization potential has not been well investigated. In this study we employed, Local lymph node assay: 5-bromo-2-deoxyuridine-flow cytometry method (LLNA: BrdU-FCM) to predict the skin sensitization (SS) potential of nanoparticles. LLNA: BrdU-FCM is a method for screening of SS potential that addressed the activation and proliferation of T-lymphocytes, key event-4 (KE-4), on adverse outcome pathway (AOP) for SS. Mn2O3 (5%, 10%, and 25%), and CuO (5%, 10%, and 25 %) NPs were suspended in dimethyl sulfoxide (DMSO) for experimentation. AOO (acetone: olive oil = 4:1) and α-hexyl cinnamaldehyde were used as negative and positive control respectively. Mn2O3 and CuO NPs were both classified as non-sensitizer with maximum stimulation indices of 1.4 and 0.99 respectively. Although both NPs were classified as non-sensitizer using LLNA: BrdU-FCM, further assays addressing other KEs of AOP for SS could be carried out as confirmation and cautious use of products containing these nanoparticles is recommended as various studies have revealed their toxicity in vitro . This study was supported by the Korea National Research Foundation (grant number: 2020R1I1A3A0403650911) and the Ministry of Environment-Educational training program for the management of information on the hazards and risk of chemical substances.