Fluorescent Nanoparticles Delivered Gene/Drug Toward Pest Control

In recent decades, the nanotechnology develops rapidly in various research fields. With the excellent properties, nanomaterials have become a new hotspot in biomedical field. Some nanomaterials can function as novel non-viral vectors, lacking the risk of inflammatory, immunogenic, and mutagenic effects caused by viral vectors. These nanomaterials possess precisely controlled nanosize, much cavity internal and bear large numbers of functional groups, which lead to promising application prospects as gene or drug vectors. Hower, the common used gene or drug vectors still have high cytotoxicity and poor water solubility that limit the delivery efficiency.By preliminary screening, we obtained two kinds of fluorescence nanoparticles (Perylene-3,4:9,10-tetracarboxylic acid diimide, PDI):star polymers and dendrimers. They have nanosize, strong fluorescence, good water solubility, biocompatibility, low cytotoxicity and high gene or drug delivery efficiency. We used these nanopartiles as gene or drug vectors in live cells as well as pest control.The star polymers can efficiently enter into live cells with low cytotoxicity as well as high gene delivery efficacy. Using insect models, oral feeding, was selected in which the mixture of star polymer/CHT10-dsRNA complex was incorporated into insect’s diet. CHT10is a midgut specific chitinase gene expressed in the gut of the Asian corn borer which is known to prevent embryo hatch, larval molting, pupation, and adult metamorphosis of insects. The expression of targeted gene CHT10was efficiently knocked down in fed larvae. This specific knock down of key developmental genes leads to severe defects in larval growth and molt leading to death. The genetic control of insect pests through a non-viral gene delivery system to knock down key development genes opens a new avenue for the pest control.The dendrimers are water-soluble and biocompatible with fluorescence detection, low cytotoxicity and remarkable gene transfection efficiency. Increasing dendrimer generation increased their ability for gene transfection. In addition, the dendrimers provide the cavities for the encapsulation of hydrophobic insecticide thiamethoxam that is in the class of neonicotinoids and has pesticidal activity against homoptera pests. These dendrimers efficiently delivered drug into live insect cells to enhance drug cytotoxicity. Using a nontarget pest of this drug, by incorporating the mixture of dendrimer/drug complex into the diet of the pests, the mortality of the fed larvae was efficiently elevated compared with that of the treatment with drug alone. This novel application can efficiently increase the pesticide effects and extend insecticidal target pests. This method would be useful to avoid the overuse of chemical pesticides.