Even with pre-operative imaging methods, surgeons still depend on visual inspection in order to located malignant tissues during surgery.
A new study released on November 14th, 2017 at the 2017 American Association of Pharmaceutical Scientists (AAPS) Annual Meeting and Exposition could help surgeons better locate and treat these tumor cells with engineered naphthalocyanine-based nanoparticles (SiNc-PNP) that are injected 24 hours prior to surgery, which then light up when they come into contact with cancerous tumors.
In the study, title "Single Theranostic Agent for Image-Guided Surgery and Intraoperative Phototherapy for Cancer Treatment," researchers created an activatable theranostic nanoplatform that can be employed for two purposes: delineation of tumor with a real-time near-infrared (NIR) fluorescence signal during surgery, and an intraoperative targeted treatment to eliminate hard-to-remove tumors further by non-toxic phototherapy.
You can relate these nanoparticles like a light switch, they are off until the tumor cells turn them on, tumor cells can be close to healthy tissue, blood vessels and more, making them challenging to remove. The surgeon can shine the near-infrared light on the now-glowing cells and these nanoparticles will absorb the light transferring it to a heat to eliminate the tumor cells.
Oleh Taratula, study's lead researcher, assistant professor of pharmaceutics, Oregon State University.
The created nanoparticles were successfully delivered to, accumulated at, and penetrated into the center of tumors in animal models. Then, these activatable SiNc-encapsulated polymeric nanoparticles switched on the NIR fluorescence at the tumor site, providing high cancer-to-tissue contrast imaging.
Fluobeam® 800, an FDA-approved intraoperative NIR imaging system, was used to demonstrate the feasibility of activatable SiNc-PNP for real-time intraoperative image-guided surgery, where sensitive fluorescence detection of cancerous tumors was observed for tumor resection.
Phototherapy during surgery in mice showed successful removal of the subcutaneous tumor with the fluorescence signal from SiNc. The NIR light was shown on the cancerous tumor 24 hours after injection (10 minutes) of the nanoparticles. When treated with this single dose of phototherapy, chemoresistant tumors were completely removed from the mice and there was no tumor recurrence during the experiment.
Taratula added, "We think these nanoparticles could be a powerful diagnostic and treatment tool to enhance surgical outcomes and patient prognosis for a variety of cancers in the future."
As a next step, the researchers will confirm the efficiency of the phototheranostic nanoplatform by performing image-guided surgery together with phototherapy in additional animal models.