Preparation of p-amino salicylic acid-modified polysuccinimide as water-based nanocarriers for enhancing pesticide stability and insecticidal activity

Avermectin (AVM) is a biopesticide with low toxicity and high activity, but has limited use due to its poor water solubility and easy decomposition. A delivery system that can stabilize this biopesticide can play a significant role for improving its biological activity. Herein, water-dispersible functionalized polysuccinimide nanoparticles (PAD) were prepared by a ring-opening reaction and subsequently used to encapsulate AVM via self-assembly to form [email protected] nanoparticles with a loading ratio of 10.04 %. The half-life under UV radiation (300 W) of [email protected] was three times higher than that of free AVM, demonstrating the excellent protective ability of PAD. In addition, [email protected] nanoparticles could sustain the release of AVM for 70 h with a cumulative release rate of 70 %. [email protected] nanoparticles also showed a pH-responsive release, and their maximum cumulative release rate was at neutral pH. Moreover, the median lethal concentration (LC50) value of [email protected] with respect to Plutella xylostella was 34.50 mg/L, while that of free AVM was 56.05 mg/L. These results showed that the [email protected] nanoparticles can potentially and effectively promote drug stability and biological activity in agriculture.