In vitro skin decontamination of the organophosphorus pesticide Paraoxon with nanometric cerium oxide CeO 2

• Published in: Chemico-biological interactions 2017-04, Vol.267, p.57-66
• Main Authors: Salerno, Alicia, Devers, Thierry, Bolzinger, Marie-Alexandrine, Pelletier, Jocelyne, Josse, Denis, Briançon, Stéphanie
• Format: Article
• Language: English
• Subjects: Aluminum Compounds - pharmacology; Animals; Cerium - chemistry; Chemical and Process Engineering; Chromatography, High Pressure Liquid; Decontamination - methods; Engineering Sciences; Galenic pharmacology; Life Sciences; Magnesium Compounds - pharmacology; Metal Nanoparticles - chemistry; Metal Nanoparticles - ultrastructure; Paraoxon - analysis; Paraoxon - toxicity; Pesticides - analysis; Pesticides - toxicity; Pharmaceutical sciences; Photolysis - radiation effects; Silicates - pharmacology; Skin - drug effects; Skin - pathology; Skin Cream - pharmacology; Spectrophotometry, Ultraviolet; Swine; Ultraviolet Rays
• ISSN: 0009-2797; 1872-7786
• DOI: 10.1016/j.cbi.2016.04.035

Organophosphorus compounds (OP), which mainly penetrate via the percutaneous pathway, represent a threat for both military and civilians. Body surface decontamination is vital to prevent victims poisoning. The development of a cost-effective formulation, which could be efficient and easy to handle in case of mass contamination, is therefore crucial. Metal oxides nanoparticles, due their large surface areas and the large amount of highly reactive sites, present high reactivity towards OP. First, this study aimed at evaluating the reaction of CeO nanoparticles, synthetized by microwave path and calcined at 500 or 600 °C, with Paraoxon (POX) in aqueous solution. Results showed that both nanoparticles degraded 60%-70% of POX. CeO calcined at 500 °C, owing to its larger specific area, was the most effective. Moreover, the degradation was significantly increased under Ultra-Violet irradiation (initial degradation rate doubled). Then, skin decontamination was studied in vitro using the Franz cell method with pig-ear skin samples. CeO powder and an aqueous suspension of CeO (CeO -W) were applied 1 h after POX exposure. The efficiency of decontamination, including removal and/or degradation of POX, was compared to Fuller's earth (FE) and RSDL lotion which are, currently, the most efficient systems for skin decontamination. CeO -W and RSDL were the most efficient to remove POX from the skin surface and decrease skin absorption by 6.4 compared to the control not decontaminated. FE reduced significantly (twice) the absorbed fraction of POX, contrarily to CeO powder. Considering only the degradation rate of POX, the products ranged in the order CeO  > RSDL > CeO -W > FE (no degradation). This study showed that CeO nanoparticles are a promising material for skin decontamination of OP if formulated as a dispersion able to remove POX like CeO -W and to degrade it as CeO powder.