Dr. Baran Sumer (left) and Dr. Jinming Gao invented a transistor-like threshold sensor that can illuminate cancer tissue to assist surgeons. To view a video on this story, go to utsouthwestern.edu/nanosensors.

The high acidity of cancer cells yielded the clue that led to the development of a tool that significantly improves surgeons’ abilities to remove cancerous tissues. The invention by UT Southwestern researchers is a transistor-like threshold sensor that hones in on high pH, literally lighting up cancerous cells. 

Using mouse models, the UTSW team was able to demonstrate the nanosensor’s ability to light up a broad set of solid cancers, distinguishing them from healthy, normal cells. The study is published in Nature Biomedical Engineering.

“We synthesized an imaging probe that stays dark in normal tissues, but switches on like a lightbulb when it reaches solid tumors. The purpose is to allow surgeons to see tumors better during surgery,” said senior author Dr. Jinming Gao, Professor of Pharmacology and Otolaryngology with the Harold C. Simmons Comprehensive Cancer Center.

That’s important to the millions of patients facing cancer. According to the National Cancer Institute, there are 15.5 million cancer survivors in the U.S., representing 4.8 percent of the population. The number of cancer survivors is projected to increase by 31 percent, to 20.3 million, by 2026.

Used during surgery, the new nanosensor amplifies acidic pH signals in the tumor microenvironment to more accurately distinguish them from normal tissue.

The nanosensors lit up on this image show cancer tissue at the microscopic level. The blue background is muscle tissue.

“Cancer is a very diverse set of diseases, but it does have some universal features. Tumors do not have the same pH as normal tissue. Tumors are acidic, and they secrete acids into the surrounding tissue. It’s a very consistent difference,” said Dr. Baran Sumer, Associate Professor of Otolaryngology and co-senior author of the study.

As a result of this work, the researchers founded a UTSW spinoff company, OncoNano Medicine Inc., which plans to launch the first-in-human, phase one clinical trial this year to evaluate safety and tolerability in patients with solid cancers. This trial will be followed by phase two efficacy studies in several cancer indications before going on to multicenter phase three clinical trials.

The researchers hope the improved surgical technology can eventually benefit cancer patients in multiple ways, including more accurate removal of tumors and greater preservation of functional normal tissue. These advantages can improve both survival and quality of life.