Synthetic polymer nanocarrier enhances dsRNA stability but not RNAi efficacy in Brassicogethes aeneus

The use of double-stranded RNA (dsRNA) for pest insect management presents a promising strategy for protecting crop yields, preserving ecosystem integrity and improving food security and safety. However, to address the natural instability of dsRNA, nanocarriers have been developed to enhance both its stability and cellular uptake in vivo. This study evaluates the laboratory efficacy of naked vs complexed dsRNA in the RNAi-mediated control of the pollen beetle Brassicogethes aeneus, a major insect pest of rapeseed crops. After selecting a synthetic cationic polymer that successfully protects dsRNA from degradation by B. aeneus gut nucleases, pollen beetles were orally exposed to either complexed or naked dsRNA targeting essential genes.

Our results demonstrate that the low-molar-mass synthetic polymer nanocarrier PAEMA enhances the stability of dsRNA in the insect gut environment and facilitates its release. However, it does not lead to an increased mortality rate of B. aeneus.

These findings suggest that nanocarrier systems achieving successful dsRNA complexation and enhanced stability do not necessarily result in a significant reduction of survival in pollen beetles. They also highlight the need for a deeper understanding of the complexation and release conditions specific to each dsRNA-nanocarrier system within a relevant biological context to develop effective dsRNA delivery strategies for B. aeneus control. © 2026 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.