'Quadrapeutics' works in preclinical study of hard-to-treat tumors

Two years ago, scientists at Rice University came up with the new treatment, which involves extremely small particles of gold entering cancer cells and then being heated by a laser until tiny bubbles surround them and explode, ripping apart the cancer cell.

Even better, if the bubbles don’t manage to kill the cancer cells immediately, they leave them weakened for traditional chemotherapy drugs.

Now, the results of the technique’s pre-clinical trials in mice have been reported in Nature Medicine, and they’re extremely encouraging.

The researchers tested the technique on head and neck squaomous cell carcinomas that had grown immune to chemotherapy in mice. Within one week, the cancerous tumours were destroyed, even though the scientists only used 3 percent of the typical drug dose, and 6 percent of the typical radiation.

The researchers believe the effectiveness of the treatment should not be limited to these types of cancers, and it’s likely to work on various solid tumours, especially those in the brain, lung and prostate, Dexter Johnson reports for IEEE Spectrum.

The treatment is called a quadrapeutic therapy, because the gold nanoparticles are only one part of the four-pronged attack (as shown in the illustration above).

This chemotherapy drug is the first step in the attack. Next, gold nanoparticles are introduced into the body, tagged with antibodies that target and attach to the surface of specific cancer cells. 

The cancer cells ingest these nanoparticles, where they're blasted with near-infrared laser pulses - a wavelength of light that can’t be absorbed by the gold. Instead, the light excites the free electrons on the gold nanoparticles and causes them to heat up and generate energy, eventually making the cancer cells to explode.

“What kills the most-resistant cancer cells is the intracellular synergy of these components and the events we trigger in cells,” study leader Dmitri Lapotko said in a press release. “This synergy showed a 100-fold amplification of the therapeutic strength of standard chemoradiation in experiments on cancer cell cultures.”

This Rice University video describes the technique in more detail.