Drug candidate shrinks tumor when delivered by plant virus nanoparticle

In a pair of firsts, researchers at Case Western Reserve University and Massachusetts Institute of Technology have shown that the drug candidate phenanthriplatin can be more effective than an approved drug in vivo, and that a plant-virus-based carrier successfully delivers a drug in vivo.

Triple-negative breast cancer tumors of mice treated with the phenanthriplatin -carrying nanoparticles were four times smaller than those treated either with cisplatin, a common and related chemotherapy drug, or free phenanthriplatin injected intravenously into circulation.

The scientists believe the work, reported in the journal ACS Nano, is a promising step toward clinical trials. "We may have found the perfect carrier for this particular drug candidate," said Nicole Steinmetz, an assistant professor of biomedical engineering at Case Western Reserve, who has spent 10 years studying the use of plant viruses for medical purposes.

She teamed with Stephen J. Lippard, Arthur Amos Noyes Professor of chemistry at MIT, and an expert in biological interactions involving platinum-based chemotherapies.

Platinum-based drugs are used to treat more than half of cancer patients receiving chemotherapy. Two of the most commonly used drugs are cisplatin and carboplatin. They form bifunctional cross-links with DNA in cancer cells, which block the DNA from transcribing genes and result in cell death, Lippard explained.