Author ORCID Identifier

Year of Publication


Degree Name

Master of Science (MS)

Document Type

Master's Thesis


Agriculture, Food and Environment



First Advisor

Dr. Bruce A. Webb


Traditional methods of pest control are threatened by the development of insecticide resistance, both to traditional insecticides and Bt toxins. Discovery of RNA interference (RNAi) has created opportunities to develop new insect control mechanisms. However, RNAi responses appear to be robust in coleopteran pests, but other orders, e.g. Lepidoptera and Hemiptera, present varied or ineffective RNAi responses. Current delivery strategies for double-stranded RNA (dsRNA) include microinjection, ingestion, and soaking. These approaches have benefits and problems. This study investigates the potential for porous silica nanoparticles (pSNPs) to improve the delivery of dsRNA and induce an RNAi response in Spodoptera frugiperda cells. Initially, the binding conditions of RNA onto porous and nonporous silica nanoparticles was examined, and the movement of RNA on and within pSNPs was observed. That information was then applied to in vitro studies for examining the capacity of silica nanoparticles to protect dsRNA from degradation by nucleases. This work culminated in an in vivo assay for measuring apoptosis when dsRNA is delivered to insect cells by pSNPs. Results of these studies show that silica nanoparticles bind nucleic acids and that dsRNA is mobile, pSNPs protect dsRNA from nuclease degradation, and pSNP/dsRNA complexes can induce apoptosis in lepidopteran insect cells.

Digital Object Identifier (DOI)