While scientists are working tirelessly to find new and effective solutions to cancer, many patients currently undergo chemotherapy, a treatment that comes with a whole host of deeply unpleasant side effects, such as vomiting, hair loss, and a weakened immune system.
The issue is that chemotherapy drugs are toxic, and while they kill cancer cells, they also spread to untargeted parts of the body via the blood. One way to tackle this is directly delivering the drugs to the tumor site via catheters, but more than 50 percent still escapes from the target organ.
Now, scientists have created a tiny device that sits inside a vein and acts like a sponge, mopping up the excess chemo drug after it’s left the tumor site. It’s essentially a tiny tube coated in a drug-absorbing polymer that allows blood to flow through unhindered.
It’s still very early days for the device – so far it has only been tested in pigs – but it has given some very promising results. In their experiment, researchers from the University of California (UC), Berkeley, focused on the liver, publishing their findings in the journal ACS Central Science.
"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," said Steven Hetts, an interventional radiologist at the University of California, San Francisco. (Intra-arterial chemo is more targeted than regular chemotherapy and involves administering the drug to the artery or arteries that supply the tumor via a catheter.)
The team injected a chemotherapy drug called doxorubicin into each pig's blood upstream of the liver, and inserted their device in a vein downstream. After the drug had left the liver, it passed through the device.
Excitingly, 64 percent of the excess doxorubicin was removed from the blood. The tiny sponge managed to retain all of the drug that it absorbed, so it didn’t leach back into the body.
"Surgeons snake a wire into the bloodstream and place the sponge like a stent, and just leave it in for the amount of time you give chemotherapy, perhaps a few hours," explained Nitash Balsara of UC Berkeley. Each session would require a fresh device, which could be tailored to the patient’s body as the little sponges are 3D printed.
While promising, the research still has a way to go before the technique can be used in people. As Steve Rannard of Cancer Research UK told BBC News, "We now need to build a greater body of evidence to ensure this technique is safe before we can see if this could be an effective approach in cancer patients."
If proved safe and effective, the sponge's temporary nature could mean that it is approved for use quicker than permanent devices. “There is a lower bar in terms of approval by the FDA,” said Hetts. "I think this type of chemofilter is one of the shortest pathways to patients."