Scientists have discovered a remarkable new way to destroy cancer cells. Stimulating aminocyanine molecules with near-infrared light caused them to vibrate in synchrony, enough to rupture cancer cell membranes.
Aminocyanine molecules are already used in bioimaging as synthetic dyes. Commonly used in low doses to detect cancer, they remain stable in water and are very good at attaching themselves to the outside of cells.
How the vibration mechanism works. ( Ciceron Ayala-Orozco et al., Nature Chemistry , 2023 )
The research team from Rice University, Texas A&M University and the University of Texas said the new approach is a marked improvement over another type of cancer-killing molecular machine developed previously, called Feringa-type motors, which also could break down problematic cell structures.
“It’s a whole new generation of molecular machines that we call molecular jackhammers,” said Rice University chemist James Tour when the results were published in December 2023.
“They are more than a million times faster in their mechanical movement than the old Feringa-type engines, and can be activated with near-infrared light instead of visible light.”
Using near-infrared light is important because it allows scientists to go deeper into the body. Bone and organ cancer could potentially be treated without the need for surgery to target the growth of the cancer .
In tests on cancer cells grown in the laboratory, the molecular jackhammer method achieved a 99% success rate in destroying the cells. The approach was also tested in mice with melanoma tumors , and half of the animals became cancer-free.
The structure and chemical properties of aminocyanine molecules mean they stay in sync with the right stimulus – like near-infrared light. When in motion, electrons within molecules form what are known as plasmons , collective vibratory entities that drive movement throughout the molecule.
“What needs to be highlighted is that we have discovered another explanation for how these molecules might work,” said Rice University chemist Ciceron Ayala-Orozco.
“This is the first time that a molecular plasmon has been used in this way to excite the entire molecule and to actually produce a mechanical action used to achieve a specific goal – in this case, tearing the membrane of cancer cells.”
Plasmons have an arm on one side, helping to connect the molecules to the cancer cell membranes while the vibrations move them apart. It’s still early days for research, but these initial findings are very promising.
This is also the type of direct biomechanical technique that cancer cells would have difficulty developing any kind of block against . Next, researchers are looking at other types of molecules that could be used in a similar way.
“This study is about a different way to treat cancer using mechanical forces on a molecular scale,” said Ayala-Orozco.
The research was published in Nature Chemistry .
