Flexible polymer implant for localised cancer treatment

Researchers from MIT and Massachusetts General Hospital (MGH) have developed an implantable polymer device that delivers chemotherapy drugs directly to pancreatic tumours.

The implant, described in the journal Biomaterials, consists of a flexible film made from a polymer called PLGA (poly lactic-co-glycolic acid), which is widely used for drug delivery and other medical applications. After the film is embedded with chemotherapy drugs, it can be rolled into a narrow tube and inserted through a catheter. Once the film reaches the pancreas it unfolds and conforms to the shape of the tumour, with medication secreted only from the side of the film in contact with the growth.

Once the film reaches the pancreas, it unfolds and conforms to the shape of the tumour. (Credit: Bryce Vickmark)
Once the film reaches the pancreas, it unfolds and conforms to the shape of the tumour. (Credit: Bryce Vickmark)

“It’s clear there is huge potential for a device that can localise treatment at the disease site,” said one of the study’s lead authors Laura Indolfi, a postdoctoral student at MIT’s Institute for Medical Engineering and Science (IMES) and the MGH Cancer Centre.

“You can implant our device to achieve a localised drug release to control tumour progression and potentially shrink it to a size where a surgeon can remove it.”

In a study on mice, the researchers found that treatment using the PLGA implant was up to 12 times more effective than giving chemotherapy drugs by intravenous injection. Injections are traditionally used to treat pancreatic cancer, but this can often be ineffective due to the organ’s location deep within the body, as well as the tendency for pancreatic tumours to have few blood vessels to absorb the drugs.

Once the film reaches the pancreas, it unfolds and conforms to the shape of the tumour. (Credit: Bryce Vickmark)
(Credit: Bryce Vickmark)

According to the researchers, direct delivery to the tumour significantly improved the concentration of chemotherapy drugs in the desired area, with the film also providing a physical barrier over the tumour to reduce metastasis to nearby organs. While the focus from the outset has been the pancreas, the implant could potentially be used to treat other hard-to-reach tumours, such as in the gastrointestinal tract.

It has also been suggested that the film could form the coating of a stent to prevent blockage of the bile duct, something that commonly affects pancreatic cancer patients. Coating stents with the drug-releasing film could help stop the cancer cells from spreading into the duct.

“We can extend the lifespan of these devices [stents],” said Indolfi. “Rather than being replaced every month they could be replaced every six months, or once a year.”