Schematic representation of the mechanisms by which light-activated molecular machines kill fungi. Image courtesy of Tour Group/Rice University.
That stubborn athlete’s foot infection an estimated 70% of people get at some point in their life could become much easier to get rid of thanks to nanoscale drills activated by visible light. Proven effective against antibiotic-resistant infectious bacteria and cancer cells, the molecular machines developed by Rice University chemist James Tour, PhD, and collaborators are just as good at combating infectious fungi.
Based on the work of Nobel laureate Bernard Feringa, PhD, the Tour group’s molecular machines are nanoscale compounds whose paddlelike chain of atoms moves in a single direction when exposed to visible light. This causes a drilling motion that allows the machines to bore into the surface of cells, killing them. In contrast to most antifungals, development of resistance to the visible-light activated nanoscale drills was not detected. Spinning at 2 to 3 million times per second, their rotors cause fungal cells to disintegrate by disrupting their metabolism.
“Our molecules differ from conventional antifungals in that they specifically target what we call the powerhouses of the cell, that is, the mitochondria,” said collaborator Ana Santos, a Rice alumna who is currently a Marie Curie Global Postdoctoral Fellow at Fundación Instituto de Investigación Sanitaria Islas Baleares in Spain. “By targeting the mitochondria, our molecules disrupt the cell’s metabolism, resulting in an overall energy imbalance that leads to an uncontrolled flow of water and ions such as calcium into the cell, eventually causing the cell to explode,” Santos explained.
