A fluorescent nanomedicine tool for cancer may help to identify which tissues to remove, as well as to kill malignant cells that can’t be cut out with surgery, a new study from Oregon State University reports.
The study, “A Tumor-Activatable Theranostic Nanomedicine Platform for NIR Fluorescence-Guided Surgery and Combinatorial Phototherapy,” appeared in the journal Theranostics.
The technology contains nanoparticles tightly loaded with a dye. These particles can be injected either intravenously or into the peritoneum (the membrane lining the abdominal cavity). The intracellular environment of the cancerous cells appears able to turn on the particles’ fluorescence once they accumulate at the tumor site. Importantly, this process is specific to tumor cells and is non-toxic.
The light is then detected by a near infrared (NIR) imaging system, which helps surgeons identify cancerous spots not otherwise visible.
In addition, any fluorescent cancer areas that can’t be removed (are unresectable) can be irradiated with a NIR laser, which heats up the nanoparticles to kill the remaining tumor cells. This process is called phototherapy.
“We have developed an activatable theranostic nanoplatform that can be used concurrently for two purposes: (1) tumor delineation with real-time near infrared (NIR) fluorescence signal during surgery, and (2) intraoperative targeted treatment to further eliminate unresected disease sites by non-toxic phototherapy,” the researchers wrote.
The nanomedicine tool has silicon naphthalocyanine (SiNc), a light-sensitive molecule designed to be non-fluorescent until accumulating at a cancer site, and packed in biodegradable particles.
Researchers analyzed the technology in lab-cultured cells and in two mouse models, including one mimicking ovarian intraperitoneal metastasis. The tool’s efficacy was shown in both approaches.
Studies in lab-grown cells also showed that the phototherapy could efficiently eliminate ovarian cancer tumors resistant to chemotherapy.
The work in mice used real-time imaging, demonstrating the new nanoparticles are compatible with an existing, U.S. Food and Drug Administration (FDA)-approved imaging device called Fluobeam 800.
Researchers plan to further test their tool on rats, and then on dogs already scheduled for cancer surgeries at the university’s College of Veterinary Medicine.
“The nanoplatform system is quite simple but quite effective,” Olena Taratula, a lead study author, said in a press release. “They’re going to do surgery on those dogs anyway, and they can use our nanomedicine platform as an additional tool to see if they can identify the cancer cells.”