A drug sponge developed by UC Berkeley chemical engineers could sop up the residual drug, lessening the side effects of cancer treatment.
With the help of sponges inserted in the bloodstream to absorb excess drugs, doctors are hoping to prevent the dangerous side effects of toxic chemotherapy agents or even deliver higher doses to knock back tumours that don’t respond to more benign treatments.
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 – the liver in liver cancer, for example. There, it would sop up any drug not absorbed by the tumour, preventing it from reaching and potentially poisoning other organs.
In early tests in pigs, the polymer-coated drug absorber took up, on average, 64% of a liver cancer drug – the chemotherapy agent doxorubicin – injected upstream.
Most anticancer drugs are poisonous, so doctors walk a delicate line when administering chemotherapy. A dose must be sufficient to kill or stop the growth of cancer cells, but not high enough to irreparably damage the patient’s other organs.
Even so, chemotherapy is typically accompanied by major side effects, including nausea, vomiting, diarrhoea and suppression of the immune system, not to mention hair loss and ulcers.
“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 UC San Francisco.
“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.
“Ultimately we would like to use this technology in other organs to treat kidney tumours and brain tumours.”