Smart polymer probe for image-guided surgery could improve outcomes for cancer patients

By: 
July 27, 2018

SurgeryDid you get it all? It’s one of the first things patients ask after undergoing cancer surgery, as well they should. Many cancer patients don’t die from the primary malignant tumor, but rather from the spread of lingering cancer cells to other parts of the body. These cells may be impossible to spot using even advanced imaging technologies. A polymeric “smart probe” developed by researchers at Tel Aviv University (TAU) may be able to help surgeons locate cancer cells more precisely and remove more of them in a single procedure than ever before, reports online news magazine Israel21c.

The smart probe is injected into the patient a few hours prior to surgery and uses near-infrared technology to identify cancer cells.

“The probe is a polymer that connects to a fluorescent tag by a linker,” explained lead researcher Prof. Ronit Satchi-Fainaro of the physiology and pharmacology department at TAU’s Sackler Faculty of Medicine. “This linker is recognized by an enzyme called cathepsin that is overproduced in many cancer types. Cathepsin cleaves the tag from the polymer and turns on its fluorescence at a near-infrared light,” said Satchi-Fainaro.

In addition to guiding the surgeon in real time during tumor excision, the smart probe also can help the surgeon avoid harming non-glowing healthy tissue.

“In cases of melanoma and breast cancer, for example, the surgeon may believe he or she . . . has excised the entire tumor and left the remaining tissue free of cancer. Even if only a few cells linger after surgery, too few or too small to be detected by MRI or CT, recurrence and metastasis may occur,” Satchi-Fainaro said. “Our new technology can guide the surgeon to completely excise the cancer.”

Studies done on mice revealed that smart-probe-guided surgery reduced recurrence and metastasis of the cancer and increased survival rates compared with routine procedures, according to the researchers.

The scientists are currently working on unique polymeric “Turn-ON” probes for image-guided surgery that can be activated by other analytes, such as reactive oxygen species (ROS), which are overproduced in cancer tissues, or by using other chemi-luminescent probes.

“The probe may also reduce the need for repeated surgeries in patients with cancer cells that remain on the edges of removed tissue,” Satchi-Fainaro said. “Altogether, this may lead to the improvement of patient survival rates.”

The research team also included lab students Rachel Blau, Yana Epshtein and Evgeni Pisarevsky. They published their discovery in the journal Theranostics in June.