Miniature, implantable LED device fights cancer with light

Light therapy has proven effective in treating superficial and nearby skin cancers when used with a light-activated drug. However, cancers deep in the body, surrounded by tissue, blood, and bone, have been difficult to treat with light.

To address this challenge, engineers and scientists at the University of Notre Dame have developed an implantable wireless LED device. This device, when combined with a photosensitive dye, not only eliminates cancer cells but also activates the immune system’s ability to attack cancer. The results of this research are published in the journal Photodiagnosis and Photodynamic Therapy.

“Some colors of light penetrate tissue deeper than others” said Thomas O’Sullivan, assistant professor of electrical engineering and co-author of the paper. “It turns out that a type of light — in this case green — that doesn’t penetrate as deeply can trigger a stronger response against cancer cells.”

In order for the light to effectively destroy cancer cells, the cells must be given a dye containing light-absorbing molecules. Once the device is activated, the dye converts the light into energy, which in turn makes the cells’ oxygen toxic, essentially turning the cancer cells against each other.

Although other treatments also use cell oxygen as a weapon, this device induces a particularly beneficial type of cell death.

“Working together, biochemistry graduate student Hailey Sanders and electrical engineering graduate student SungHoon Rho astutely noticed that the treated cells swelled, a hallmark of a type of cell death, pyroptosis, that is particularly effective in triggering an immune response.” said Bradley Smith, Emil T. Hofman Professor of Science and co-author of the paper. “Our goal is to induce even a small amount of pyroptotic cell death, which will then stimulate the immune system to begin attacking the cancer.”

In upcoming studies, the device will be tested in mice to determine whether the immune system can recognize and eliminate other malignancies on its own, based on the cell-killing response initiated in one of the tumors.

O’Sullivan noted that the device, about the size of a grain of rice, could be implanted directly into a tumor and remotely activated via an external antenna. The goal is to use the device not only to deliver treatments but also to monitor tumor response, adjusting signal strength and timing as needed.

One of the first Seed Transformative Interdisciplinary Research (STIR) grants funded this study as part of a group of four projects. In 2023, the Notre Dame College of Science and College of Engineering launched grants to launch research projects in human health, the environment, and information technology in science and engineering.

Magazine reference:

1. Sunghoon Rho, Hailey S. Sanders, Bradley D. Smith, Thomas D. O’Sullivan. Miniature Wireless LED Device for Photodynamic Cell Pyroptosis. Photodiagnosis and Photodynamic Therapy, 2024; DOI: 10.1016/j.pdpdt.2024.104209