Researchers at the Massachusetts Institute of Technology have developed an adhesive patch that can stick to the site of a colorectal cancer tumor, either before or after surgery, to deliver drug, gene and photo therapy to reduce the chance of tumor recurrence.

The general approach to cancer treatment today is the use of whole-body therapies such as chemotherapy drugs. But the lack of specificity of anticancer drugs means they produce undesired side effects when systemically administered. What’s more, only a small portion of the drug reaches the tumor site itself, meaning the primary tumor is not treated as effectively as it could be.

“This means that we are treating both the source of the cancer—the tumor—and the metastases resulting from that source in a suboptimal manner,” says Natalie Artzi, principal research scientist at MIT’s Institute for Medical Engineering and Science, who led the research. “That is what prompted us to think a little bit differently, to look at how we can leverage advancements in materials science, and in particular nanotechnology, to treat the primary tumor in a local and sustained manner.”

Researchers at MIT have developed an adhesive patch that can be applied to a tumor site either before or after surgery. Image credit: Ella Maru.The triple-therapy hydrogel patch Artzi and her colleagues devised contains gold nanorods that heat up when near-infrared radiation is applied to the local area to destroy the tumor. These nanorods are equipped with a chemotherapy drug that is released when they are heated, to target the tumor and its surrounding cells. Gold nanospheres that do not heat up in response to the near-infrared radiation are used to deliver RNA, or gene therapy, to the site to silence an important oncogene that can cause healthy cells to transform into tumorous cells.

The researchers envision that a clinician could remove a tumor and then apply the patch to the inner surface of the colon to ensure that no cells that are likely to cause cancer recurrence remain at the site. As the patch degrades, it would gradually release the various therapies. The patch could also serve as a neoadjuvant, a therapy designed to shrink tumors prior to their resection.

When the approach was tested in mice, the researchers found that in 40% of cases in which the patch was not applied after tumor removal, the cancer returned. But when the patch was applied after surgery, the treatment resulted in complete remission. Even when the tumor was not removed, the triple-combination therapy alone was enough to destroy it.

In the next phase of their work, the researchers hope to move to experiments in larger models in order to use colonoscopy equipment not only for cancer diagnosis but also to inject the patch to the site of a tumor when detected.

“This administration modality would enable, at least in early-stage cancer patients, the avoidance of open field surgery and colon resection,” Artzi says.