Department of Environmental Engineering, UNESP-Univ. Estadual Paulista, Avenida Três de Março, no. 511, 18087-180 Sorocaba, SP, Brazil; Department of Biochemistry, Institute of Biology, UNICAMP, Cidade Universitária Zeferino Vaz, s/n, Campinas, SP, Brazil.
Department of Biotechnology, University of Sorocaba, Sorocaba, SP, Brazil.
J Hazard Mater. 2014 Aug 15;278:163-71. doi: 10.1016/j.jhazmat.2014.05.079. Epub 2014 Jun 11.
Paraquat is a fast acting nonselective contact herbicide that is extensively used worldwide. However, the aqueous solubility and soil sorption of this compound can cause problems of toxicity in nontarget organisms. This work investigates the preparation and characterization of nanoparticles composed of chitosan and sodium tripolyphosphate (TPP) to produce an efficient herbicidal formulation that was less toxic and could be used for safer control of weeds in agriculture. The toxicities of the formulations were evaluated using cell culture viability assays and the Allium cepa chromosome aberration test. The herbicidal activity was investigated in cultivations of maize (Zea mays) and mustard (Brassica sp.), and soil sorption of the nanoencapsulated herbicide was measured. The efficiency association of paraquat with the nanoparticles was 62.6 ± 0.7%. Encapsulation of the herbicide resulted in changes in its diffusion and release as well as its sorption by soil. Cytotoxicity and genotoxicity assays showed that the nanoencapsulated herbicide was less toxic than the pure compound, indicating its potential to control weeds while at the same time reducing environmental impacts. Measurements of herbicidal activity showed that the effectiveness of paraquat was preserved after encapsulation. It was concluded that the encapsulation of paraquat in nanoparticles can provide a useful means of reducing adverse impacts on human health and the environment, and that the formulation therefore has potential for use in agriculture.
百草枯是一种快速作用的非选择性接触除草剂，在世界范围内广泛使用。然而，该化合物的水分溶解度和土壤吸附性可能会导致非目标生物中毒的问题。本工作研究了壳聚糖和三聚磷酸钠（TPP）组成的纳米粒子的制备和特性，以生产一种更高效、毒性更低的除草剂制剂，用于更安全地控制农业杂草。使用细胞培养活力测定法和洋葱染色体畸变试验评估了制剂的毒性。研究了在玉米（Zea mays）和芥菜（Brassica sp.）栽培中纳米封装除草剂的除草活性，并测量了纳米封装除草剂的土壤吸附。百草枯与纳米粒子的效率关联为 62.6±0.7%。封装除草剂会改变其扩散和释放，以及其在土壤中的吸附。细胞毒性和遗传毒性试验表明，纳米封装除草剂的毒性比纯化合物低，表明其具有控制杂草的潜力，同时减少对环境的影响。除草活性的测量表明，封装后百草枯的有效性得以保留。因此，可以得出结论，将百草枯封装在纳米粒子中可以提供一种减少对人类健康和环境的不利影响的有用方法，因此该制剂有可能用于农业。
