Hetts specializes in treating eye tumors by navigating a tube, called a catheter, from the femoral artery in the thigh to the opthalmic artery that supplies blood to the affected eye, and pumping chemotherapy medication through the catheter to the tumor.

"You can get very high concentrations of that chemotherapy in the eye and relatively low concentrations in the rest of the body, but some will wash through the eye and into the veins in the head," Hetts said, "so you can have side effects from that."


Hetts began to question, "Is there a way to drain, to remove that excess drug before it has side effects? If you can remove a lot of the drug, you could escalate the dose of the drug you can give, for better tumor control and potentially a cure -- and you could basically eliminate any side effects.

"It occurred to me that maybe we could navigate a separate catheter into the vein that drains the blood, and have a material that binds up any excess chemotherapy," he said.

While the eye cancers he treats are rare -- there are several hundred children per year in the U.S. who are affected by this kind of tumor--he saw a parallel need to improve the treatment options for liver cancer, which is far more pervasive: It is the third-leading cause of cancer deaths globally, with an estimated half a million new cases each year.

Bringing a medical device from drawing board to market

In 2013 his staff reached out to Nitash Balsara, a senior scientist at Berkeley Lab and a chemical engineering professor at UC Berkeley and lead-PI of the Soft Matter Electron Microscopy program in Berkeley Lab's Materials Sciences Division, to pursue the idea, and Chen began to work on materials based on Hetts' concept. The research team received a patent for a ChemoFilter system in April.

The patented device features a nickel-titanium metal frame in a collapsible flower-petal array, attached to a thin polymer membrane that can be expanded out from a catheter to absorb a drug. In a preclinical study, a ChemoFilter device was inserted into a pig and was found to reduce the peak concentration of the chemotherapy drug doxorubicin by about 85 percent.

The device will hopefully find use in human cancer treatment within a couple of years, Hetts said.

Next-gen drug-capture devices

Chen and other researchers are also working on next-generation ChemoFilter devices that use a different mix of materials and different methods to remove drugs from the body, though those will likely take longer to receive federal approval for use.

Medical Research Homepage