Plant-Derived Virus-Like Nanoparticles Enlisted for Cancer Drug Delivery

Recombinant shell nanoparticles produced by plants could be used for the targeted delivery of drugs that treat cancer, according to a study published in ACS Nano.

For the study, the authors used plant-based transient expression of the Bluetongue virus (BTV) structure proteins VP3 and VP7 to obtain high yields of empty and green fluorescent protein (GFP)-encapsidating core-like particles (CLPs) from leaves.

Single particle cryo-electron microscopy was used to study both types of particles. The results of the study showed for the first time, considerable differences in CLP structure were compared with the crystal structure of infection-derived CLPs. Contrastingly, the 2 recombinant CLPs had an identical external structure.

Using the knowledge of the nanoparticles’ detailed structure, the investigators genetically and chemically engineered them to label the interior of empty CLPs with a fluorescent bioconjugate.

CLPs that contained 120 GFP molecules and CLPs containing approximately 150 dye molecules both bonded to human integrin via a naturally occurring Arg-Gly-Asp motif found on an exposed loop of the VP7 trimeric spike.

The findings indicated that the plant-made virus particles—–which naturally bind to receptors on cancer cells––were taken in by human breast cancer cells, which suggests that the nanoparticles could be used for the targeted delivery of drugs.

“BTV CLPs present themselves as a useful tool in targeted cargo delivery,” the authors wrote. “These results highlight the importance of detailed structural analysis of VNPs in validating their molecular organization and the value of such analyses in aiding their design and further modification.”