A Star Polycation Acts as a Drug Nanocarrier to Improve the Toxicity and Persistence of Botanical Pesticides

Abstract

The excessive use of chemical pesticides brings many environmental problems. Botanical pesticides seem to be a good alternative to control pests, but their slow action and lack of residual action constrain their further application. Here, we developed a star polycation (SPc) as the drug nanocarrier that could combine matrine into a complex to decrease its particle size to the nanoscale. The combination of SPc and matrine increased the zeta potential and the noncovalent molecular interaction, such as hydrogen bonds and hydrophobic interactions playing an important role in the complex formation. The nanosized matrine/SPc complex exhibited a higher cytotoxicity and an enhanced lethal effect on insect pests compared to those of matrine alone. As a botanical pesticide adjuvant, the SPc could increase the control efficacies of matrine, D-limonene, and pyrethrin against insect pests, achieving a great improvement in toxicity and persistence. The construction of SPc provides a powerful tool for delivering pesticides to increase their control efficacies and decrease their application amounts and rates, showing great potential for sustainable pest management.

Nanometerization of thiamethoxam by a cationic star polymer nanocarrier efficiently enhances the contact and plant‐uptake dependent stomach toxicity against green peach aphids

“…Incorporation of nanoparticles into conventional insecticides can be used to improve AI solubility 18, 28 . Our previous study confirmed a smaller particle size for matrine/SPc complex compared with matrine, suggesting that SPc could be used as an insecticide adjuvant to decrease the particle size of insecticides to the nanoscale and improve water‐solubility 39 . In the current study, pure thiamethoxam was used to determine the interaction between insecticide and nanocarrier.…”

“…The thiamethoxam was able to spontaneously assemble with SPc through electrostatic interaction, which might be attributed to interaction between the positively charged tertiary amine in the side chain of SPc and negatively charged nitro group in thiamethoxam. Complexation of SPc with matrine or G2 with thiamethoxam was different and both were non‐covalent molecular interactions, such as hydrogen bonds and hydrophobic interactions 37, 39 . SPc could be complexed with exogenous substances through different interaction mechanisms, which was beneficial for extending its application.…”

“…To solve these problems, we developed a star polycation (SPc) using a simplified synthetic procedure and common commercial chemical source 38 . Previous studies with matrine showed that water‐solubility was significantly improved through complexing with SPc, and the nano‐sized matrine/SPc complex exhibited higher cytotoxicity and an enhanced lethal effect on insect pests 39 . Whether SPc can be used as a common adjuvant is an interesting topic, and some issues remain to be addressed.…”

Nanoparticle‐mediated double‐stranded RNA delivery system: A promising approach for sustainable pest management

“…Yan et al (2020b) applied this star polycation as a highly efficient gene carrier, and the dsRNA/nanoparticle formulation targeting V-ATPaseD and chitin synthase1 genes was directly sprayed onto soybean seedlings infected with Aphis glycines, resulting in a good control effect (mortality rate: 78.5%). This star polycation can also be used as a pesticide adjuvant to improve the toxicity and persistence of botanical pesticides (Yan et al, 2019). Sprayable RNAibased products can be easily applied as chemical pesticides, and the application of this nanoparticle to deliver pesticide and dsRNA simultaneously may be a good option for foliar spray.…”

“…Each repeated branched layer represents a higher generation molecule, and the dendrimer surface can be engineered to build a variety of functions (Boas & Heegaard, 2004; Chen & Yin, 2014). Modified dendrimers are not only used for drug delivery, but are also attractive means of delivering plasmid DNA, antisense oligonucleotides, and siRNA/dsRNA because of the high density of positive charges on their surfaces (Perez‐Martinez et al ., 2012; Yan et al ., 2019). The high water solubility of cationic dendrimers enables them to be good nucleic acid nanocarriers during biological applications (Sun et al ., 2016).…”