Embrapa Environment, Rod SP 340, km 127.5, 13918-110, Jaguariúna, São Paulo, Brazil.
Department of Environmental Engineering, Sorocaba Institute of Science and Technology (ICTS), São Paulo State University (Unesp), Avenida Três de Março, 511, 18087-180, Sorocaba, São Paulo, Brazil.
NanoImpact. 2022 Jul;27:100408. doi: 10.1016/j.impact.2022.100408. Epub 2022 May 31.
Organophosphate insecticides such as dimethoate (DMT) are widely used in agriculture. As a side effect, however, these insecticides contaminate bodies of water, resulting in damage to aquatic organisms. The development of nanopesticides may be an innovative alternative in the control of agricultural pests, increasing effectiveness and reducing their toxicological effects. Based upon this, the present study has investigated encapsulated DMT in alginate chitosan nanoparticles (nanoDMT) and evaluated its toxicological effects on non-target organisms. The nanoparticles were characterized by DLS, NTA and AFM, as well as being evaluated by the release profile. Nanoparticle toxicity was also evaluated in comparison with DMT, empty nanoparticles and DMT (NP + DMT), and commercial formulations (cDMT), in the embryos and larvae of Danio rerio (zebrafish) according to lethality, morphology, and behavior. The nanoparticle control (NP) showed hydrodynamic size values of 283 ± 4 nm, a PDI of 0.5 ± 0.05 and a zeta potential of -31 ± 0.4 mV. For nanoparticles containing dimethoate, the nanoparticles showed 301 ± 7 nm size values, a PDI of 0.45 ± 0.02, a zeta potential of -27.9 ± 0.2 mV, and an encapsulation of 75 ± 0.32%, with slow-release overtime (52% after 48 h). The AFM images showed that both types of nanoparticles showed spherical morphology. Major toxic effects on embryo larval development were observed in commercial dimethoate exposure followed by the technical pesticide, predominantly in the highest tested concentrations. With regard to the toxic effects of sodium alginate/chitosan, although there was an increase for LC-96 h concerning the technical dimethoate, the behavior of the larvae was not affected. The data obtained demonstrate that nanoencapsulated dimethoate reduces the toxicity of insecticides on zebrafish larvae, suggesting that nanoencapsulation may be safer for non-target species, by eliminating collateral effects and thus promoting sustainable agriculture.
有机磷杀虫剂如乐果（DMT）在农业中广泛使用。然而，作为一种副作用，这些杀虫剂会污染水体，从而对水生生物造成损害。纳米农药的发展可能是控制农业害虫的一种创新替代方法，可以提高效果并降低其毒理学效应。基于此，本研究研究了包封在海藻酸钠壳聚糖纳米颗粒（nanoDMT）中的 DMT，并评估了其对非靶标生物的毒理学效应。通过 DLS、NTA 和 AFM 对纳米颗粒进行了表征，并通过释放曲线进行了评价。还将纳米颗粒毒性与 DMT、空纳米颗粒和 DMT（NP+DMT）以及商业制剂（cDMT）进行了比较，根据致死率、形态和行为评估了斑马鱼胚胎和幼虫的毒性。纳米颗粒对照（NP）显示出 283±4nm 的水动力粒径值、0.5±0.05 的 PDI 和-31±0.4mV 的 zeta 电位。对于含有乐果的纳米颗粒，纳米颗粒显示出 301±7nm 的粒径值、0.45±0.02 的 PDI、-27.9±0.2mV 的 zeta 电位和 75±0.32%的包封率，随着时间的推移释放速度较慢（48 小时后释放 52%）。AFM 图像显示两种类型的纳米颗粒均呈现球形形态。商业乐果暴露后观察到对胚胎幼虫发育的主要毒性作用，随后是技术农药，主要在最高测试浓度下。关于海藻酸钠/壳聚糖的毒性作用，虽然技术乐果的 LC-96h 有所增加，但幼虫的行为不受影响。获得的数据表明，纳米包封的乐果降低了杀虫剂对斑马鱼幼虫的毒性，表明纳米包封可能对非靶标物种更安全，通过消除附带影响，从而促进可持续农业。
