Active targeting of Rhizoctonia solani in rice using WGA-functionalized mesoporous silica nanoparticles

Developing active targeting strategies for agrochemical delivery is paramount for simultaneously enhancing fungicide efficacy and mitigating off-target environmental risks. This study reports the development of wheat germ agglutinin (WGA)-functionalized mesoporous silica nanoparticles (MSNs) as a nanocarrier system designed to actively target fungal cell walls. These MSNs were loaded with the fungicide Fluazinam (Flu) to yield Flu@MSNs-WGA, which exhibited an average hydrodynamic diameter of 44.54 nm and a Fluazinam loading content of 10.89 % ± 0.27 %. Studies investigating transport and distribution in rice plants demonstrated that the WGA-functionalized nanoparticles were absorbed by roots and leaves and exhibited specific accumulation at sites of Rhizoctonia solani infection, confirming active targeting. Furthermore, In vitro assays revealed that the antifungal activity of Flu@MSNs-WGA against R. solani was significantly enhanced compared to the non-targeted nanocarrier (Flu@MSNs-COOH) and was 2.7 times higher than that of a commercial Fluazinam suspension concentrate (Flu SC) formulation. Representing the first application of WGA for targeted pesticide delivery, this work validates the feasibility of this approach, providing essential proof-of-concept and technical support for developing novel, actively targeted nano-pesticides for improved crop protection.