After surgery, chemotherapy and radiation are two of the most common cancer treatments today. While quite effective, these therapies are also notorious for inflicting collateral damage to nearby healthy cells and organs of the cancer patient. Scientists have been experimenting several ways to prevent this problem by inventing techniques that only target cancer cells.
At Rice University, researchers have come up with a combination treatment that combines existing standard therapies with novel techniques. This so-called quadrapeutics therapy uses chemotherapy, radiation, lasers and nanoparticles to destroy cancer cells from within.
As published in the journal Nature Medicine, a team from Rice, the University of Texas MD Anderson Cancer Center and Northeastern University, used quadrapeutics to treat head and neck squamous cell carcinoma, a deadly and drug-resistant type of cancer.
Rice scientist Dmitri Lapotko had previously devised a technique using “plasmonic nanobubbles” that expand and burst inside cancer cells when triggered by lasers. He and his team combined the same technique with other methods in quadrapeutics.
According to the study, the first component involved the introduction of chemotherapy drugs, doxorubicin and paclitaxel, that were encapsulated and tagged with antibodies to target specific cancer cells. The plasmonic nanobubbles make it possible for the chemo drugs to be more concentrated inside the cell, thereby reducing the typical dose needed.
The second part is a solution of gold colloids that are tagged with cancer-specific antibodies. These particles form nanoclusters inside cancer cells.
These nanoclusters are triggered by a third component, a short near-infrared laser pulse that uses 1 million times less energy that a conventional surgical laser. The pulse can be given on demand through a standard endoscope. The action produces the plasmonic nanobubbles that magnify the effect of chemo drugs introduced earlier.
The last component is a single, low-dose of radiation. Again, the plasmonic nanobubbles amplify the effects of radiation inside cancer cells, so that even low-doses can be effective.
According to the researchers, quadrapeutics achieves three effects: mechanical cell destruction, intracellular drug ejection and radiation amplification -- in the detection and destruction of cancer cells but not healthy cells.
In their experiment, they said that this four-in-one treatment was “17 times more efficient than conventional chemoradiation therapy against aggressive, drug-resistant head and neck tumors.” Just three percent of the conventional chemotherapy drug dose and six percent of the usual radiation dose destroyed head and neck tumors in mice within a week of quadrapeutics therapy.
Although the study focused on treating head and neck squamous cell carcinoma, the team hopes that quadrapeutics can also be tried against brain, lung and prostate cancer.
“We address aggressive cancers that cannot be efficiently and safely treated today,” Lapotko, the study team’s lead scientist, said in a statement. “Quadrapeutics steps up when standard treatments fail. At the same time, quadrapeutics complements current approaches instead of replacing them.”
“Quadrapeutics shifts the therapeutic paradigm for cancer from materials — drugs or nanoparticles — to mechanical events that are triggered on demand only inside cancer cells,” said Lapotko. “Another strategic innovation is in complementing current macrotherapies with microtreatment. We literally bring surgery, chemotherapies and radiation therapies inside cancer cells.”