Efficient and rapid multiscale approach of polymer membrane degradation and stability: Application to formulation of harmless non-oxidative biocide for polyamide and PES/PVP membranes

International audienceMembrane cleaning and disinfection is a bottleneck in the filtration processes of the food industry. Disinfection by oxidative agents, such as NaOCl, have been clearly identified as the main responsible of the accelerated ageing of polymer membranes. The development of new formulated biocide detergents allowing to respect the integrity of polymer membranes is our objective. A major difficulty to overcome is to have a method making it possible to rapidly demonstrate whether the membrane will age after a long-time contact with the biocide in industrial conditions of use. However, nowadays the estimation of membrane ageing is mainly achieved by long-time consuming methods, limiting biocide and detergent developments. This paper proposes an original approach allowing a time-efficient discrimination of biocide detergent prototypes with respect to the membrane long-term ageing. The methodology is firstly based on the use of microwaves activation to accelerate the membrane degradation (if any) in the biocide solution set at a concentration selected to avoid too severe degradations never reached at industrial scale. Secondly, the combination of MW results and short time filtration gives rapidly relevant information about the suitability (or not) of a tested prototype with respect to the membrane flux behaviour. ATR-FTIR characterisation is shown to be relevant as the single analytical tool to follow the entire approach. Finally, only the promising prototype enter in long-term filtration validation tests, with a real opportunity to avoid unnecessary experiments. For the sake of the demonstration, the methodology is applied aiming at the formulation of a non-oxidative formulated biocide detergent that can be used either for RO or UF. The results evidence a non-intuitive conclusion: the new biocide validated for RO polyamide membrane (fragile toward NaOCl biocide oxidant and hydrophilic) has to be avoided for the more chemically resistant but also more hydrophobic UF PES/PVP membrane

Induction of Experimental Autoimmune Encephalomyelitis With Recombinant Human Myelin Oligodendrocyte Glycoprotein in Incomplete Freund's Adjuvant in Three Non-human Primate Species

<p>The experimental autoimmune encephalitis (EAE) model is used for preclinical research into the pathogenesis of multiple sclerosis (MS), mostly in inbred, specific pathogen free (SPF)-raised laboratory mice. However, the naive state of the laboratory mouse immune system is considered a major hurdle in the translation of principles from the EAE model to the MS patient. Non-human primates (NHP) have an immune system harboring T- and B-cell memory against environmental antigens, similar as in humans. We sought to further refine existing NHP EAE models, which may help to bridge the gab between mouse EAE models and MS. We report here on new EAE models in three NHP species: rhesus monkeys (Macaca mulatta), cynomolgus monkeys (Macaca fascicularis) and common marmosets (Callithrix jacchus). EAE was induced with recombinant human myelin oligodendrocyte glycoprotein extracellular domain (1-125) (rhMOG) formulated in incomplete Freund's adjuvant (IFA). IFA lacks the bacterial antigens that are present in complete Freund's adjuvant (CFA), which are notorious for the induction of discomforting side effects. Clinically evident EAE could be induced in two out of five rhesus monkeys, six out of six cynomolgus monkeys and six out of six common marmosets. In each of these species, the presence of an early, high anti-rhMOG IgM response is correlated with EAE with an earlier onset and more severe disease course. Animals without an early high IgM response either did not develop disease (rhesus monkeys) or developed only mild signs of neurological deficit (marmoset and cynomolgus monkeys).</p>