Plant and insect virus-like particles: emerging nanoparticles for agricultural pest management

Functionally Modified Graphene Oxide as an Alternative Nanovehicle for Enhanced dsRNA Delivery in Improving RNAi-Based Insect Pest Control

RNA interference (RNAi) has shown substantial promise as a sustainable pest management solution. However, the efficacy of RNAi-based insecticides heavily relies on advanced nanocarrier-mediated delivery systems. In this study, we modified raw graphene oxide into positively charged nanocarriers (GONs) tailored to bind with double-stranded RNA (dsRNA). The resulting GONs@dsRNA complexes demonstrated a small particle size (106 nm) and maintained stability under various conditions, including insect gut extracts, extreme pH, and extreme temperature. Furthermore, GONs efficiently transported dsRNA molecules into Drosophila S2 cells and Lepidoptera Sf9 cells, leading to an enhanced target transcript knockdown. Targeting the vacuolar ATPase gene, vha26, induced significant mortality and target transcript knockdown in D. suzukii adults but not in S. exigua. Finally, GONs@dsRNA complexes exhibited negligible cytotoxicity at both the cellular and organismal levels. This study demonstrates the potential of GONs as a biosafe nanovehicle for efficient dsRNA delivery into insects, presenting an alternative strategy for advancing RNAi applications in fundamental studies and pest control.

Drosophila X virus-like particles as delivery carriers for improved oral insecticidal efficacy of scorpion Androctonus australis peptide against the invasive fruit fly, Drosophila suzukii

Insect-specific neurotoxic peptides derived from the venoms of scorpions and spiders can cause acute paralysis and death when injected into insects, offering a promising insecticidal component for insect pest control. However, effective delivery systems are required to help neurotoxic peptides pass through the gut barrier into the hemolymph, where they can act. Here, we investigated the potential of a novel nanocarrier, Drosophila X virus-like particle (DXV-VLP), for delivering a neurotoxin from the scorpion Androctonus australis Hector (AaIT) against the invasive pest fruit fly, Drosophila suzukii. Our results show that the fusion proteins of DXV polyproteins with AaIT peptide at their C-termini could be sufficiently produced in Lepidoptera Hi5 cells in a soluble form using the recombinant baculovirus expression system, and could self-assemble into VLPs with similar particle morphology and size to authentic DXV virions. In addition, the AaIT peptides displayed on DXV-VLPs retained their toxicity, as demonstrated in injection bioassays that resulted in severe mortality (72%) in adults after 72 h. When fed to adults, mild mortality was observed in the group treated with DXV-AaIT (38%), while no mortality occurred in the group treated with AaIT peptide, thus indicating the significant role of DXV-VLPs in delivering AaIT peptides. Overall, this proof-of-concept study demonstrates for the first time that VLPs can be exploited to enhance oral delivery of insect-specific neurotoxic peptides in the context of pest control. Moreover, it provides insights for further improvements and potentially the development of neurotoxin-based bioinsecticides and/or transgenic crops for insect pest control.

Precise Therapy Using the Selective Endogenous Encapsidation for Cellular Delivery Vector System

Interindividual variability in drug response is a major problem in the prescription of pharmacological treatments. The therapeutic effect of drugs can be influenced by human genes. Pharmacogenomic guidelines for individualization of treatment have been validated and used for conventional dosage forms. However, drugs can often target non-specific areas and produce both desired and undesired pharmacological effects. The use of nanoparticles, liposomes, or other available forms for drug formulation could help to overcome the latter problem. Virus-like particles based on retroviruses could be a potential envelope for safe and efficient drug formulations. Human endogenous retroviruses would make it possible to overcome the host immune response and deliver drugs to the desired target. PEG10 is a promising candidate that can bind to mRNA because it is secreted like an enveloped virus-like extracellular vesicle. PEG10 is a retrotransposon-derived gene that has been domesticated. Therefore, formulations with PEG10 may have a lower immunogenicity. The use of existing knowledge can lead to the development of suitable drug formulations for the precise treatment of individual diseases.