Polymer Implant Delivers Drugs to Pancreatic Tumors

A novel implantable delivery platform can provide local chemotherapy for treating pancreatic ductal adenocarcinoma (PDAC), according to a new study.

Developed by researchers at the Massachusetts Institute of Technology (MIT, Cambridge, MA, USA) and Massachusetts General Hospital (MGH; Boston, MA, USA), the implant is a biodegradable polymer flexible film made of poly lactic-co-glycolic acid (PLGA), and is designed to release high doses of chemotherapeutic drugs for up to 60 days. For delivery, the film is rolled into a tube and inserted through a catheter; once it reaches the pancreas, it unfolds and conforms to the shape of the tumor, releasing the embedded drugs only from the tumor-facing side to reduce side effects.

To compare the device's efficacy to that of traditional chemotherapy, a study was conducted in mice carrying human pancreatic tumors. One group of mice was treated with the implant carrying the chemo drug paclitaxel, while the other group received injections of the same drug for four weeks, simulating current treatment for human patients. The results showed that tumor growth slowed in mice with the implant; in some cases, the tumors even shrank. After four weeks, the implant group showed five times the paclitaxel concentration in their tumors that the intravenous group did.

In addition to successfully delivering the drug to the pancreas, the researchers also observed other positive effects. The localized treatment increased the amount of necrotic tissue, and since there are few blood vessels in pancreatic tumors, the paclitaxel tended to remain in-situ, preventing toxic effects in healthy tissues. Additionally, by acting as a physical barrier, the film was able to reduce metastasis to nearby organs. The study describing the implant and the murine study was published early online on March 31, 2016, in Biomaterials.

“The greatest benefit of this device is the ability to implant it with minimally invasive procedures, so we can give a tool to oncologists and surgeons to reach tumors that otherwise would be difficult to reach,” said lead author Laura Indolfi, PhD, of the MIT Institute for Medical Engineering and Science (IMES) and the MGH Cancer Center. “You can implant our device to achieve a localized drug release to control tumor progression and potentially shrink the tumor to a size where a surgeon can remove it.”

Pancreatic cancer patients often suffer from blockage of the bile duct, which interferes with digestion and is very painful. The duct can be reopened with a stent, but usually gets blocked again, requiring the patient to have the old stent removed and a new one inserted. According to the researchers, the film could also be used as a coating for such a stent, helping to prevent the cancer cells from spreading into the bile duct and blocking it again.

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