Mitochondrial targeting and pH-responsive release of dual-functionalized mesoporous silica nanoparticles as pesticide carrier

Abstract

BACKGROUND: Suitable nano-pesticide carriers play a crucial role in enhancing the utilization efficiency of pesticides. Among these, mesoporous silica nanoparticles (MSNs) are the most promising candidates for large-scale and safe pesticide applications. RESULTS: In the present work, functionalized MSNs were demonstrated to be effective mitochondrial-targeted carriers for delivering strobilurin fungicides (mitochondrial respiratory chain inhibitors). MSNs were bi-functionalized with carboxymethyl chitosan (CMC), which is pH-responsive, and (4-carboxybutyl) triphenylphosphonium bromide (TPP), which is mitochondrial targeting. The loading capacity of the model pesticide pyraclostrobin (Py) on the carrier reached 32%. In vitro release experiments of Py demonstrated the sustained release performance of the carriers. Co-localization of the mitochondria and the carrier confirmed that mitochondria targeting by the nanoparticle carrier. Bioactivity assays showed superior antifungal activity of bi-functionalized Py@MSNs-CMC-TPP compared to mono-functionalized MSNs and commercial Py suspension products. Moreover, even when the concentrations of Py@MSNs-CMC and Py commercial suspension were increased by 200% relative to Py@MSNs-CMC-TPP, inhibition remained lower. This indicates that the bi-functionalized carrier reduced the required amount of Py while enhancing its utilization efficiency. CONCLUSION: With the large-scale application of mitochondrial-targeted pesticides, such as methoxyacrylates and succinate dehydrogenase inhibitors, functionalized MSNs have significant potential to emerge as promising, environmentally friendly fungicide formulation. © 2025 Society of Chemical Industry.