Medical Applications of Plant Virus Nanoparticles

Plant viruses have recently come to the fore within the nanomedicine field. The advantages of these protein-based nanoparticles for use in medical applications include their inherent ability to withstand harsh environments, making them amendable for functionalization and formulation, their biocompatibility and biodegradability, their inherent ability to self-assemble into structurally uniform particles as well as being non-infectious and incapable of replicating in mammalian cells. Due to their proteinaceous nature, plant viral nanoparticles (VNPs) can be modified, and foreign cargo can be encapsulated within the capsid or attached to their interior or exterior capsid surfaces. The various cargo-loading processes used to tailor plant VNPs for biomedical applications include cargo infusion or caging, and genetic and chemical engineering of the VNPs allows for the display of targeting ligands/molecules, functional handles, antibodies, antigenic structures, proteins and small molecule drugs, amongst others. The morphology of plant VNPs can also be manipulated to change a particle’s properties to meet the requirements of a specific application. Bioengineered plant VNPs are being employed for the targeted delivery of drugs, nucleic acids, enzymes and proteins/peptides, immunotherapy and vaccines, and agents for medical imaging and therapeutics, all medical applications that will be discussed here.