In the fight against cancer, an important field of research is the search for safe alternatives to chemotherapy and radiotherapy. These treatments attack both cancer cells and healthy cells, exposing patients to serious side effects.
A team of scientists from the University of Texas at Austin and the University of Porto in Portugal have just brought an alternative one step closer. They’ve developed materials capable of converting near-infrared light, or NIR, efficiently and safely into heat that can be highly targeted against cancer cells. Their materials are tin oxide (SnOx) nanoflakes, tiny particles that have a thickness of less than 20 nanometers (a nanometer is one-thousand-millionth of a meter).
The team’s findings, published in the journal ACS Nano, offer new hope for the design of photothermal therapies, the name given to these types of light-based treatments.
A photothermal therapy is a noninvasive procedure that heats up cancer cells in order to destroy them. It works by infiltrating cancer cells with materials that absorb light and turn it into heat—in this case, the SnOx nanoflakes—which can be designed so that they accumulate specifically in tumor tissues. They are then targeted with light at a wavelength that gives these materials the energy they need to produce cancer-killing heat but which doesn’t damage healthy tissues.
The researchers propose that their SnOx nanoflakes could improve these types of treatments by offering greater thermal efficiency, biocompatibility, and affordability than other materials that are used in such processes.
“Our goal was to create a treatment that is not only effective but also safe and accessible,” said Jean Anne Incorvia, a UT professor of engineering and one of the project leaders, in a press statement. “With the combination of LED light and SnOx nanoflakes, we’ve developed a method to precisely target cancer cells while leaving healthy cells untouched.”
To evaluate the thermal efficiency of their new material, the team developed a proprietary system based on near-infrared LEDs (NIR-LEDs) that emit light at a wavelength of 810 nanometers, which is safe for biological tissues. Unlike traditional laser systems, NIR-LEDs provide more homogeneous and stable illumination, reduce the risk of overheating, and require minimal investment. The entire experimental set-up, capable of irradiating up to 24 samples at the same time, cost approximately $530, making it an affordable and versatile tool for biomedical research.
Results from beaming NIR onto SnOx-treated cancer cells have been encouraging. UT reported that in as little as 30 minutes of exposure, the method killed up to 92 percent of skin cancer cells and 50 percent of colorectal cancer cells. This was achieved without any harmful effects to healthy skin cells, demonstrating the safety and selectivity of this approach.
