Researchers at Houston Methodist have developed a biodegradable implant that can be used to safely and consistently deliver drug treatments to tumors and then dissolve without the need for further surgery.

The implant is only the size of a grain of rice, but its potential is staggering. The biodegradable nanofibrous drug-eluting seed (b-NDES) works as a reservoir parked inside a soft tumor, where it can slowly release immune-stimulating drugs over time. This overcomes a consistent problem with drugs such as immune checkpoint inhibitors. Normal systemic administration sees comparatively little of the drug making its way to the tumor, with most of it circulating throughout the body. The b-NDES is like deploying a small guerrilla fighting force embedded in enemy territory, doing maximum damage to the entrenched tumor.

"To improve cancer treatment, we're trying to start a fire inside the tumor itself," Corrine Chua, associate professor in the Center for BioNanoengineering at Houston Methodist Research Institute, said in a news release. "By activating immune cells directly within the tumor microenvironment, those cells can then travel throughout the body and seek out cancer wherever it exists. The b-NDES platform was developed to help keep therapeutic drugs concentrated inside tumors while minimizing exposure to healthy tissues.”

Chua co-led the study with Alessandro Grattoni, chair and director of the Center for BioNanoengineering at Houston Methodist Research Institute.

The study included support from the Nancy Owens Breast Cancer Foundation and the National Institutes of Health/National Cancer Institute.

Chau and Grattoni used preclinical models of triple-negative breast cancer, an aggressive form of cancer that is estrogen receptor-negative, progesterone receptor-negative and HER2-negative. Because of the receptor negativity, some popular treatments like tamoxifen and trastuzumab are ineffective. Chemotherapy has been shown to be the best course of action.

The b-NDES implant is deployed alongside radiation drugs. It keeps the drugs focused on the tumor, reducing the amount of harmful side effects typically seen when drugs are circulated more widely in the body. In 60 percent of the models, tumors were eliminated and did not cause side effects beyond the tumor site. Once the drugs have been deployed, the implant breaks down naturally.

While promising, more research will have to be done to expand use to other tumor types.

"Although the study focused on triple-negative breast cancer models, the approach could have broader applications for solid tumors," Grattoni added in the release. "It could potentially be used in cancers where there is a tumor lesion accessible for placement, including pancreatic or lung cancers."