Shape-shifting nanoparticles anchor to tumor cells, deliver drugs

Shape-shifting nanoparticles respond to triggers and anchor to tumors.--Courtesy of UCSD

Researchers at the University of California in San Diego have created a nanoparticle that begins its journey in the bloodstream as a tiny sphere, then assembles into a solid "net" when it reaches a tumor, delivering drugs there with more durability.

In a study published in the journal Advanced Materials, researchers showed that they could trigger the shape-shifting nanoparticles to anchor themselves to cancer cells, holding them in place to deliver tumor-killing cells. Using matrix metalloproteinases (MMPs), enzymes present in some cancerous tissues that lead to metastasis, the scientists harnessed their ability to make their own nanoparticles change shape.

Each particle has a polarity that allows it to form spheres, protecting the drug as it moves through the bloodstream. But when mixed with MMPs, the tiny balls reassembled into "netlike threads," according to a report from the university. So the team used this trigger to target human fibrosarcomas, a kind of cancer with high levels of MMPs. The resulting effect persisted for at least a week.

"We figured out how to make an autonomous material that could sense its environment and change accordingly," said lead author Nathan Gianneschi in the university report. "Specifically, we wanted to design switchable materials that we could inject in one shape and have them change to another between the blood and tumors."

The research was funded by the National Institutes of Health, the Army Research Office and the Air Force Office of Scientific Research.

- here's the UCSD report