Researchers at Duke University have combined an FDA approved immunotherapy and a gold nanostar/laser treatment to completely eradicate tumors and vaccinate against the cancer.
The team’s technique involves injecting gold nanoparticles into the bloodstream. These star-shaped nanoparticles (nanostars) can accumulate in tumors after circulating within the blood. Then the tumor is blasted with a laser, causing the nanoparticles to heat up and burning the tumor.
“The nanostar spikes work like lightning rods, concentrating the electromagnetic energy at their tips,” said Tuan Vo-Dinh, a researcher at Duke University. “We’ve experimented with these gold nanostars to treat tumors before, but we wanted to know if we could also treat tumors we didn’t even know were there, or tumors that have spread throughout the body.”
The team combined the nanostar treatment with an FDA-approved immunotherapy that acts to help the body’s immune system destroy cancer cells. By combining the immunotherapy and the nanostar technique, the team hoped that they could achieve better results than with either approach alone, and also target tumors at distant sites, called metastases.
Gold nanostars (white spots) preferentially accumulate within a tumor (left) and are sparse in normal tissue (right).
The team injected bladder cancer cells into both hind legs in mice. Once tumors grew in the legs, the researchers treated the mice using different methods, but directed the nanostar laser treatment at one leg only, so that the untreated tumor represented a metastasis. Mice that received no treatment died quickly, as did those who received the nanostar treatment alone. The immunotherapy alone worked for a while, and targeted both tumors, but by the 49th day all those mice had died too.
However, mice that received both the immunotherapy and the nanostar treatment survived for longer, and two of them survived beyond 55 days. Astonishingly, one mouse was still alive nearly a year later, with no cancer recurrence. When the researchers injected more cancerous cells into this mouse, its immune system completely destroyed them, demonstrating that it had been vaccinated against this specific cancer.
This was a proof-of-concept study, but the team plans to test the technique on other types of cancer and hopes that it might be useful in humans.
Study in Scientific Reports: Synergistic Immuno Photothermal Nanotherapy (SYMPHONY) for the Treatment of Unresectable and Metastatic Cancers
Via: Duke University