Scientists have created a tiny, cylindrical “sponge” with 3D printing technology. This new device could cut down on toxic effects of cancer treatment by bringing the filtering abilities of a fuel cell into the blood vessels of living organisms. The sponge could absorb excess drug before it spreads through the body — thus lessening chemotherapy’s harmful side effects, including vomiting, immune suppression or even heart failure. It would be welded inside a vein near a tumor being treated with chemotherapy.
The problem with chemotherapy drugs for liver cancer treatments is that they affect not only the tumor and liver but also other organs throughout the body. Even with intra-arterial chemo, which limits the spread of the drug, up to half can still exit the liver to poison the rest of the body. This proposed absorber would sop up the unused drug emerging from the liver. If this device really works well doctors will even be able to deliver higher doses to knock back tumors, like liver cancer, that don’t respond to more benign treatments.
How it works: The “drug sponge” is an absorbent polymer coating a cylinder that is 3D printed to fit precisely in a vein that carries the blood flowing out of the target organ. There, it would sop up any drug not absorbed by the tumor, preventing it from reaching and potentially poisoning other organs.
Nitash Balsara, a Professor of Chemical and Biomolecular Engineering at UC Berkeley explains the inspiration behind the device:
“An absorber is a standard chemical engineering concept. Absorbers are used in petroleum refining to remove unwanted chemicals such as sulfur. Literally, we’ve taken the concept out of petroleum refining and applied it to chemotherapy.”
The sponge has been tested and proven to work in small pigs. A test of the most recent prototype showed that the absorber captured nearly two-thirds of a common chemotherapy drug infused into a nearby vein without triggering blood clots or other obvious problems in the pig.
In experiments, the team injected the liver cancer drug through the pigs’ leg and pelvic veins — which are similar in width to human liver veins, after they had inserted the 3-D printed sponge a few centimeters from the infusion site. Within a half hour, the device absorbed, on average, 64 percent of the liver cancer drug. The next round of studies they plan to do will monitor the capture of doxorubicin by drug sponges inserted directly into the pigs’ liver veins.
A human study could launch “in a couple of years, if all the stars are aligned,” said Steve Hetts, a neuroradiologist at the University of California, San Francisco. He was the one who came up with the drug-capture concept. He then worked with engineers at UC Berkeley and elsewhere to create and test the prototypes.
Hetts says the reason they are testing the device specifically for liver cancer is that it is a common health threat but this approach should be able to work the same for all organs. He explains:
“We are developing this around liver cancer because it is a big public health threat — there are tens of thousands of new cases every year — and we already treat liver cancer using intra-arterial chemotherapy. But if you think about it, you could use this sort of approach for any tumor or any disease that is confined to an organ, and you want to absorb the drug on the venous side before it can distribute and cause side effects elsewhere in the body. Ultimately we would like to use this technology in other organs to treat kidney tumors and brain tumors.”
Eleni Liapi, a radiologist at Johns Hopkins University School of Medicine not involved with the new work says the study addresses a major need because existing methods for controlling chemotherapy delivery do not fully block drug escape. “A technological advancement to reduce unwanted circulating drug is always welcome,” she notes.