Researchers have modified a plant virus to create "smart bombs" that deliver chemotherapy agents only to specific cells, without harming surrounding tissue.
NC State University researchers have modified a common, non-toxic plant virus to create “smart bombs” that are one thousand times smaller than the width of a single human hair and deliver chemotherapy agents only to specific cells, without harming surrounding tissue, potentially leading to more effective treatment and greatly reducing, or even eliminating, side effects.
The chosen virus was particularly appealing to the researchers due to its ability to live outside a plant host and because it includes a 17-nanometer internal space that can be used to carry chemotherapy right to a tumor cell. Researchers attached signal peptides to the virus’s exterior, enabling it to seek out and enter specific cancer cells, and then release the chemotherapy drug. Calcium plays a key role along the way, keeping the therapy drug enclosed while the virus travels through the bloodstream, where calcium levels are high, and allowing the virus to open within the individual cells, where calcium levels are much lower.
“We had tried a number of different nanoparticles as cell-targeting vectors,” said Dr. Stefan Franzen, professor of chemistry. “The plant virus is superior in terms of stability, ease of manufacture, ability to target cells and ability to carry therapeutic cargo.”
“Another factor that makes the virus unique is the toughness of its shell,” explained Steven Lommel, professor of plant pathology and genetics. “When the virus is in a closed state, nothing will leak out of the interior, and when it does open, it opens slowly, which means that the virus has time to enter the cell nucleus before deploying its cargo, which increases the drug's efficacy.”