Shiyuan Miao,Suisui Wang,Kaiwei Wang,Yonglin Ren,Simon J. McKirdy,Yujie Lu
Surface-modified mesoporous silica nanoparticles (MSNs) are regarded as efficient and promising nanocarriers in novel pesticide delivery. In this study, MSNs were synthesized and functionalized with low molecular weight polyethyleneimine (PEI), after which methoprene was loaded by adsorption. Detailed investigations showed that MSNs-PEI exhibited excellent encapsulation efficiency (53.33 %) and loading efficiency (21.03 %) for methoprene. The release behaviors of methoprene from Met@MSNs-PEI showed an initial rapid release stage followed by a sustained release stage. Methoprene was released faster in alkaline solutions compared with in acidic and neutral media. The kinetic study revealed that the release data fit best with the Korsmeyer-Peppas model. Additionally, Met@MSNs-PEI exhibited negligible toxicity towards S2 cells and low acute toxicity to zebrafish. Bioassay results showed that Met@MSNs-PEI exhibited significantly better insecticidal activity against Tribolium castaneum larvae than methoprene alone under the same doses of active ingredient applied, which obviously enhanced the utilization efficiency. Moreover, fluorescence microscope observations confirmed the successful internalization and distribution patterns of FITC-labeled MSNs-PEI in T. castaneum larvae, indicating that MSNs-PEI could serve as nanocarriers to deliver insecticides. RNA-seq analysis and qRT-PCR validation showed that MSNs-PEI-loaded methoprene resulted in the downregulation of genes related to detoxification, hormone synthesis, and cuticle biosynthesis, which inhibited insect growth and development. Therefore, MSNs-PEI nanoparticles provided an effective delivery system for methoprene.
Zhihua Hao,Qingyu Lu,Yanyan Zhou,Yanting Liang,Yun Gao,Huanyan Ma,Yusong Xu,Huabing Wang
The widespread use of pesticides hampers the immune system of non-target organisms, however, there is a lack of common biomarkers to detect such effects. Myeloid differentiation primary response factor 88 (MyD88) is a crucial junction protein in the Toll-like receptor signaling pathway , which plays an important role in the inflammatory response. In this study, we investigated MyD88 as a potential biomarker for pesticide-induced stress. Phylogenetic analysis revealed that MyD88 was a conserved protein in the evolution of vertebrates and invertebrates. MyD88s usually have death domain (DD) and Toll/interleukin-1 receptor (TIR) domain. Bombyx mori ( B. mori ) is an important economic insect that is sensitive to toxic substances. We found microbial pesticides enhanced the expression level of MyD88 in B. mori . Transcriptome analysis demonstrated that MyD88 expression level was increased in the fatbody after dinotefuran exposure, a third-generation neonicotinoid pesticide. Moreover, the expression of MyD88 was upregulated in fatbody and midgut by imidacloprid , a first-generation neonicotinoid pesticide. Additionally, insect growth regulator (IGR) pesticides, such as methoprene and fenoxycarb , could induce MyD88 expression in the fatbody of B. mori . These results indicated that MyD88 is a potential biomarker for pesticide-induced stress in B. mori . This study provides novel insights into screening common biomarkers for multiple pesticide stresses and important implications for the development of more sustainable pest management strategies.
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