School of Agricultural and Veterinary Sciences, São Paulo State University (UNESP), Rod. Prof. Paulo Donato Castellane, Jaboticabal SP, 14884-900, Brazil.
Brazilian Agricultural Research Corporation (EMBRAPA), Southeast Livestock Unit, Rod. Washington Luiz, Km 234 s/n, Fazenda Canchim, São Carlos, SP 13560-970, Brazil.
Vet Parasitol. 2023 Jun;318:109918. doi: 10.1016/j.vetpar.2023.109918. Epub 2023 Mar 28.
Nanoformulations containing zein nanoparticles (ZN) can promote the stability and protection of molecules with acaricidal activity. The present study sought to develop nanoformulations with ZN associated with cypermethrin (CYPE) + chlorpyrifos (CHLO) + a plant compound (citral, menthol or limonene), characterize them, and verify their efficacy against Rhipicephalus microplus ticks. Additionally, we aimed to assess its safety in nontarget nematodes found in soil at a site subjected to contamination by acaricides. The nanoformulations were characterized by dynamic light scattering and nanoparticle tracking analysis. Nanoformulations 1 (ZN+CYPE+CHLO+citral), 2 (ZN+CYPE+CHLO+menthol), and 3 (ZN+CYPE+CHLO+limonene) were measured for diameter, polydispersion, zeta potential, concentration, and encapsulation efficiency. Nanoformulations 1, 2, and 3 were evaluated in a range from 0.004 to 0.466 mg/mL on R. microplus larvae and caused mortality > 80% at concentrations above 0.029 mg/mL. The commercial acaricide Colosso® (CYPE 15 g + CHLO 25 g + citronellal 1 g) was evaluated also from 0.004 to 0.512 mg/mL and resulted in 71.9% larval mortality at 0.064 mg/mL. Formulations 1, 2, and 3 at 0.466 mg/mL showed acaricidal efficacy of 50.2%, 40.5%, and 60.1% on engorged females, respectively, while Colosso® at 0.512 mg/mL obtained only 39.4%. The nanoformulations exhibited long residual period of activity and lower toxicity to nontarget nematodes. ZN was able to protect the active compounds against degradation during the storage period. Thus, ZN can be an alternative for the development of new acaricidal formulations using lower concentrations of active compounds.
纳米制剂包含玉米醇溶蛋白纳米颗粒（ZN）可以促进具有杀螨活性的分子的稳定性和保护。本研究旨在开发含有 ZN 与氯菊酯（CYPE）+氯氧磷（CHLO）+植物化合物（柠檬醛、薄荷醇或柠檬烯）的纳米制剂，对其进行表征，并验证其对 Rhipicephalus microplus 蜱的功效。此外，我们还旨在评估其在受杀螨剂污染的地点土壤中发现的非靶标线虫中的安全性。纳米制剂通过动态光散射和纳米颗粒跟踪分析进行了表征。纳米制剂 1（ZN+CYPE+CHLO+柠檬醛）、2（ZN+CYPE+CHLO+薄荷醇）和 3（ZN+CYPE+CHLO+柠檬烯）的粒径、多分散性、zeta 电位、浓度和包封效率进行了测量。纳米制剂 1、2 和 3 在 0.004 至 0.466mg/mL 的范围内对 R. microplus 幼虫进行了评估，浓度高于 0.029mg/mL 时死亡率超过 80%。商业杀螨剂 Colosso®（CYPE 15g+CHLO 25g+柠檬醛 1g）也从 0.004 至 0.512mg/mL 进行了评估，浓度为 0.064mg/mL 时幼虫死亡率为 71.9%。制剂 1、2 和 3 在 0.466mg/mL 时对饱血雌蜱的杀螨功效分别为 50.2%、40.5%和 60.1%，而 Colosso®在 0.512mg/mL 时仅获得 39.4%。纳米制剂表现出较长的残留活性期和对非靶标线虫的较低毒性。ZN 能够保护活性化合物在储存期间免受降解。因此，ZN 可以替代使用较低浓度的活性化合物开发新的杀螨制剂。
