Chitosan nanoparticles loaded the herbicide paraquat: The influence of the aquatic humic substances on the colloidal stability and toxicity
| Autor: | Gabriela Sanches, Victor C. Chalupe, Renata de Lima, Kathleen Oehlke, Ralf Greiner, Caroline Sayuri Nishisaka, Leonardo Fernandes Fraceto, Jhones Luis de Oliveira, Claudio Martin Jonsson, Z. Clemente, Renato Grillo, André Henrique Rosa, Estefânia Vangelie Ramos Campos |
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| Rok vydání: | 2015 |
| Předmět: |
Paraquat
Environmental Engineering Carrier system Health Toxicology and Mutagenesis Nanoparticle Context (language use) medicine.disease_cause complex mixtures Chitosan chemistry.chemical_compound Chlorophyta Polyphosphates Onions Zeta potential medicine Environmental Chemistry Colloids Waste Management and Disposal Humic Substances Herbicides technology industry and agriculture Pollution chemistry Environmental chemistry Nanoparticles Ecotoxicity Genotoxicity |
| Zdroj: | Journal of Hazardous Materials. 286:562-572 |
| ISSN: | 0304-3894 |
| Popis: | Polymeric nanoparticles have been developed for several applications, among them as carrier system of pesticides. However, few studies have investigated the fate of these materials in the environment in relation to colloidal stability and toxicity. In nature, humic substances are the main agents responsible for complexation with metals and organic compounds, as well as responsible for the dynamics of these nanoparticles in aquatic and terrestrial environments. In this context, the evaluation of the influence of aquatic humic substances (AHS) on the colloidal stability and toxicity of polymeric nanoparticles of chitosan/tripolyphosphate with or without paraquat was performed. In this study, the nanoparticles were prepared by the ionic gelation method and characterized by size distribution measurements (DLS and NTA), zeta potential, infrared and fluorescence spectroscopy. Allium cepa genotoxicity studies and ecotoxicity assays with the alga Pseudokirchneriella subcapitata were used to investigate the effect of aquatic humic substances (AHS) on the toxicity of this delivery system. No changes were observed in the physical–chemical stability of the nanoparticles due to the presence of AHS using DLS and NTA techniques. However some evidence of interaction between the nanoparticles and AHS was observed by infrared and fluorescence spectroscopies. The ecotoxicity and genotoxicity assays showed that humic substances can decrease the toxic effects of nanoparticles containing paraquat. These results are interesting because they are important for understanding the interaction of these nanostructured carrier systems with species present in aquatic ecosystems such as humic substances, and in this way, opening new perspectives for studies on the dynamics of these carrier systems in the ecosystem. |
| Databáze: | OpenAIRE |
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