Banner by Dennis Doyle

Breakthrough Sponge Soaks up Chemotherapy Side Effects

by Maria Tian

Ulcers. Vomit.  Diarrhea. Hair loss.  These not only ruin a hot date night, but are also some of the serious side effects that cancer patients might experience after undergoing chemotherapy, a cancer treatment which can be administered in the form of drugs or radiation.  Every year, more than 650,000 cancer patients receive chemotherapy and more than 86% of these patients experience at least one side effect.1  These side effects can also bear heavy mental strains and stress for many chemotherapy patients and their families. Chemotherapy drugs are dangerous and can be lethal to patients if not administered appropriately. In fact, these drugs are inherently poisonous to the human body due to their cell-destroying properties.  Even a slight overdose of these drugs can cause organ and even heart failure.2 It is therefore unsurprising that, in the past, some patients have turned down chemotherapy, believing that it would only bring about more pain and torture and turning instead, to alternative therapies such as dieting and changing lifestyles. With all this in mind, patients have to ask themselves: is it worth going through chemotherapy given the many negative side effects? Fortunately, many physicians and scientists have worked hard on reducing the side effects of chemotherapy and recently, they believe they have found a method that would allow chemotherapy drugs to be a safe and efficient treatment for cancer patients.

Just a few weeks ago, scientists from the Department of Energy’s Lawrence Berkeley National Lab announced their breakthrough discovery that could greatly reduce the side effects of chemotherapy treatment. 3  Known as “The Sponge,” this 3-D circular chemo filter is made up of a polymer material containing polyethylene (which is a strong and flexible compound and is used for garbage bags) and another polymer containing negatively charged sulfonic acid. This negative charge is essential in the absorbing process: due to the positive charge on many types of chemotherapy drugs (such as doxorubicin, which is used to treat liver cancer), the negatively charged polymer material can attract and bind to the drug molecules and remove them from the bloodstream.3  According to Chelsea Chen, one of the post-doctorates at the Berkeley Lab, “In our lab experiments, the current design can absorb 90 percent of the drug in 25-30 minutes.” 2

Administering the sponge to patients would be easy and minimally invasive.  At the start of treatment, the sponge would be inserted through the veins to the targeted area. The chemotherapy medication is injected upstream of the sponge.  After a few hours, the sponge would be removed - taking the excess drugs with it. So far, the sponge has primarily been experimented to target liver cancer. According to Professor Steven Hetts, co-author of the chemo filter study in the Berkeley lab, this is due to the fact that "it is one of the big public health threats and we already treat liver cancer using intra-arterial chemotherapy.” (Intra-arterial chemotherapy is a method of delivering concentrated doses of cancer-killing medicine directly to the affected area of the eye). 2

Promising results have been observed in the first stages of experimentation on pigs. In a preclinical study, a Chemo Filter device was inserted into a pig and was found to reduce the peak concentration of the chemotherapy drug, doxorubicin, by about 85%. On average, the sponges implanted into the pigs showed an absorbance of 64% of a chemotherapy drug. 2 Scientists hope to obtain FDA approval in order to begin tests on human subjects as soon as possible.  This step is crucial since all the experimental pigs had healthy livers, which is not realistic in cancer patients. Beginning in-human studies with liver cancer patients can give a more relevant and realistic observation on how patients would respond to the sponge treatment in a real world scenario. Fortunately, because the sponge is only a temporary device, there is a lower bar in terms of approval by the FDA.  Appraised by Professor Hetts, “I think this type of chemo filter is one of the shortest pathways to patients."

Currently, there are numerous innovations already put into practice that aim to decrease the side effects of chemotherapy – the most popular is known as TACE. This treatment allows doctors to deliver chemotherapy drugs directly to the infected organ through a stent, which is a long venous tube, and can drastically reduce the flow of drugs to the rest of the body by up to 50%.  However, there still remains the issue of drug leakage. Here is where a chemo filter or sponge can come in to clean up the mess.

So far, the sponge seems to have promising results in reducing the side effects of chemotherapy, but it is far from being finished in its development.  In future studies, researchers are aiming to use this technique in the treatment of cancerous kidney tumors and brain tumors. The application of the sponge also showed promising potential in antibiotic treatments against dangerous bacterial infections while limiting their side effects.1  Scientists and researchers working with chemical engineers in the Berkeley lab continue to improve on the design and applications of this sponge as well as other chemo filter devices.  As professor Hetts of the Berkeley lab proudly proclaims, “This project has moved forward nicely and I’m really impressed. It’s been a great experience in coming together to create these devices, and I’m looking forward to continuing it.”