The toxic side-effects of chemotherapy could be reduced by a sponge-like device which strains leftover cancer drugs from the blood stream before they damage the brain or cause hair loss. US researchers showed that, in animal tests at least, up to two-thirds of the unwanted drugs were absorbed by a filter placed in a major vein leading away from the site of a tumour. If the results can be reproduced in human tests, the device could allow doctors to deliver drugs in higher doses which would usually be too toxic to be used medically.
The filter was inspired by absorbers used to remove unwanted impurities like sulphur from fuel, and works like the stents already routinely used in cardiovascular medicine, researchers from the University of California at Berkley said.
“Literally, we’ve taken the concept out of petroleum refining and applied it to chemotherapy,” Professor Nitash Balsara, one of the authors of the study published in ACS Central Science. “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.”
The research was trialled in pigs and tested on the liver cancer chemotherapy drug doxorubicin. The device, dubbed the “chemofilter” has a honeycomb structure coated with a polymer which reacts with the drug and prevents it being released – similar to the catalytic convertor in a car exhaust.
In the pig trials the device captured 64 per cent of the drug that would otherwise have circulated around the body, damaging the immune system and causing ulcers, nausea and other symptoms. Side-effects of doxorubicin in humans include hair loss, anaemia and increased risk of infection, as the circulating drugs kill off sensitive hair follicles and blood cells, according to Macmillan Cancer Support.
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Dr Steven Hetts, another of the authors, said if it’s shown to work in humans the device could be rapidly approved for patients because it’s a removable implant.
“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,” he added.
“But if you think about it, you could use this sort of approach for any tumour 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.”