Design of efficient nanoparticles for skin decontamination towards Chemical Warfare Agents – NanoDeTox

Chemical warfare agents (CWA) such as the nerve agent VX (organophosphorous OPCs) and the vesicant sulfur mustard (organochlorines OCCs), have been used recently in conflicts, but also in terrorist acts targeting civilian. Liquids or droplet aerosol forms of CWA can be absorbed through the skin, but also by many other organs such as the eyes, or the respiratory tract if there is no sufficient protection of the body surface. The first signs of percutaneous intoxication appear quickly in the form of severe functional disturbances at respiratory, cardiovascular, muscular, pupilar, digestive levels for OPCs and blistering of the skin followed by deep ulcerations for OCCs. These disturbances can lead at last to death. Body surface decontamination is therefore crucial to prevent victims poisoning. It reduces the amount of contaminant on the skin surface and thus, decreases the penetration rate and the extent of intoxication. Different decontaminant systems are currently available for skin decontamination. Some systems act by adsorption and displacement of the toxic agent such as Fuller’s Earth (FE) and other systems act by neutralization (chemical degradation) such as the Canadian Reactive Skin Decontaminant Lotion (RSDL). However, these procedures do not eliminate the toxic contaminant, which may disqualify them for use in enclosed spaces and in cases where the waste disposal cannot be ensured. Chemical procedures decompose or convert toxic substances to non-toxic or less toxic products. Generally, the reagents are suitable for a specific group of contaminants (a few are universal). Because of the shortcomings of all current decontamination methods advances in technology are necessary to increase the effectiveness of decontamination methods towards several toxic agents. The aim of the project will be to develop a universal product efficient against several CWAs, easy to handle and lost cost. New types of decontamination agents such as nanocrystalline metal oxides have been recently introduced that exhibit adsorption but also an ability to typically degrade hazardous chemicals and CWAs. The application of cerium oxide, the most abundant rare earth, has been rarely mentioned in literature but it is efficient against CWA simulants even if the mechanisms are not elucidated. Nanoparticles with specific habits and controlled granulometric distribution and non-aggregated will be designed by two main methods: Pulse Laser Ablation in Liquids and Solvothermal Synthesis Process. Both methods allow tuning the habits of particles. The main objective of this part is to correlate the physicochemical properties of particles to their degradation efficiency. Then, new materials will be designed and finally formulated. The in vitro efficiency of particles to degrade OPCs and OCCs simulants will be ranked. Finally the decontamination efficiency of the better formulations will be tested on skin explants according to the AFNOR guideline to lead to a prototype and a proof-of-concept.