Synthesis of a new magnetic-MIP for the selective detection of 1-chloro-2,4-dinitrobenzene, a highly allergenic compound.

Molecularly imprinted polymers (MIPs) in combination with magnetic nanoparticles, in a core@shell format, were studied for selective detection of 1-chloro-2,4-dinitrobenzene (CDNB), a powerful allergenic substance. Magnetic nanoparticles were prepared by the co-precipitation method and mixed with oleic acid (OA). This material was then encapsulated in three types of hydrophobic polymeric matrix, poly-(MA-co-EDGMA), poly-(AA-co-EDGMA), and poly-(1-VN-co-EDGMA), by the mini-emulsion method. These matrices were used due to their ability to interact specifically with the functional groups of the analyte. Finally, the MIP-CDNB was obtained on the magnetic-hydrophobic surfaces using precipitation polymerization in the presence of the analyte. XRD diffraction patterns suggested the presence of magnetite in the composite and SEM analysis revealed a nanoparticle size between 10 and 18nm. Under the optimized adsorption conditions, the magnetic-MIP material showed a higher adsorption capacity (5.1mgg-1) than its non-magnetic counterpart (4.2mgg-1). In tests of the selectivity of the magnetic-MIP towards CDNB, α-values of 2.5 and 10.4, respectively, were obtained for dichlorophenol and o-nitrophenol, two structurally similar compounds, and no adsorption was observed for any other non-analogous analyte. The magnetic-MIP and magnetic-NIP were applied using water enriched with 0.5mgL-1 of CDNB, achieving recovery values of 83.8(±0.8)% and 66(±1)%, respectively, revealing the suitability of the material for detection of CDNB.

Avaliaçäo da hipersensibilidade ao dinitroclorobenzeno em ratos tratados ou näo com ciclosporina / Evaluation of hipersensibility to dinitrochlorobenzeno in rats treated or not with cyclosporin-A

Avaliou-se nesse trabalho a resposta imunológica de ratos Wistar, através da hipersensibilidade tipo IV, celular ou retardada, provocada pelo DNCB em cinco grupos de 10 ratos. Para a imunizaçäo, aplicou-se sobre a pele dos animais 50 µl de DNCB, e a reaçäo foi desencadeada com concentraçöes crescentes de 10, 20, 30, 50 e 100 mg/ml na superfície da orelha esquerda e, após 24 horas, foi feita uma relaçäo de peso das orelhas esquerda/direita (controle). Todos os animais desenvolveram reaçöes de hipersensibilidade tipo IV num mesmo padräo clínico. O mesmo teste foi aplicado em cinco grupos de 5 ratos que receberam doses de 5, 7, 10, 30 e 50 mg/kg/dia de ciclosporina. Todos os animais tratados näo responderam ao teste, deduzindo-se que eles estavam imunossuprimidos pela ciclosporina