Healthcare (Commonwealth Union) – Scientists at Rice University and their collaborators have recently uncovered a novel approach to eliminating cancer cells by harnessing the ability of certain molecules to vibrate intensely when exposed to light.
The team discovered that the atoms in a small dye molecule, commonly used for medical imaging, can oscillate together—creating what’s called a plasmon—when activated by near-infrared light. This vibration causes the membranes of cancer cells to rupture. The study, published in Nature Chemistry, reported a 99% success rate against lab-grown human melanoma cells, and in experiments with mice, half of those treated for melanoma tumors were completely cured.
Rice University chemist James Tour indicated that this represents a new class of molecular tools, which they call molecular jackhammers.
His lab has previously developed nanoscale compounds with light-powered, paddle-shaped chains of atoms that spin continuously in one direction to pierce the outer membranes of harmful bacteria, cancer cells, and drug-resistant fungi.
Unlike nanoscale drills inspired by Nobel laureate Bernard Feringa’s molecular motors, molecular jackhammers operate through a completely novel—and previously unseen—mechanism.
Tour indicated that they are over a million times quicker in their mechanical motion than the former Feringa-type motors, and they are capable of being activated with near-infrared light instead of visible light.
Researchers of the study indicated that near-infrared light has the ability go in much further into the body compared to visible light, with access to organs or bones with no damaging tissue.
“Near-infrared light can go as deep as 10 centimeters (~ 4 inches) into the human body as opposed to only half a centimeter (~ 0.2 inches), the depth of penetration for visible light, which we used to activate the nanodrills,” explained Tour, Rice’s T. T. and W. F. Chao Professor of Chemistry and a professor of materials science and nanoengineering. “It is a huge advance.”
Researchers indicated that the jackhammers are aminocyanine molecules, which is a class of fluorescent synthetic dyes applied in medical imaging.
Ciceron Ayala-Orozco, a Rice research scientist who is a lead author for the research indicated that these molecules are simple dyes that individuals have put into use for a long time.
He further indicated that they are biocompatible, stable in water and have an affinity to attaching themselves to the fatty outer lining of cells, however even though they were being utilized for imaging, people were not aware how to activate these as plasmons.
Ayala-Orozco had at 1st researched plasmons as a doctoral student in the study group led by Naomi Halas of Rice University.
He indicated that as a result of their structure and chemical properties, the nuclei of these molecules is able oscillate in sync when to the right stimulus.
Ayala-Orozco further pointed out that he saw a requirement to utilize the properties of plasmons as a form of treatment and had an interest in Dr. Tour’s mechanical approach to engaging with cancer cells and he basically drew conclusions.
“The molecular plasmons we identified have a near-symmetrical structure with an arm on one side. The arm doesn’t contribute to the plasmonic motion, but it helps anchor the molecule to the lipid bilayer of the cell membrane.”
The scientists had to prove that the molecules’ mode of action was not going be categorized either as a form of photodynamic or photothermal therapy.
Ayala-Orozco indicated that what is required to be highlighted is that they have found another explanation for how these molecules are able to function.
He pointed out that is is the first instance a molecular plasmon is put into use in this way to excite the whole molecule and to actually form mechanical action utilised to achieve a particular goal and, in this incident, tearing apart cancer cells’ membrane.
