There are a wide variety of synthetic and naturally occurring
nanomaterials under development for nanoscale cargo-delivery applications.
Viruses play a special role in these developments, because they can be regarded
as naturally occurring nanomaterials evolved to package and deliver cargos.
While any nanomaterial has its advantage and disadvantages, viral nanoparticles
(VNPs), in particular the ones derived from plant viruses and bacteriophages,
are attractive options for cargo-delivery as they are biocompatible,
biodegradable, and non-infectious to mammals. Their protein-based structures are
often understood at atomic resolution and are amenable to modification with
atomic-level precision through chemical and genetic engineering. Here we present
a focused review of the emerging technology development of plant viruses and
bacteriophages targeting human health and agricultural applications. Key target
areas of development are their use in chemotherapy-, photodynamic therapy-,
pesticide-delivery, gene therapy, vaccine carriers, and immunotherapy.