Photo-excited Quantum Dots Kill Bacteria
Multidrug-resistant bacterial infections are an ever-growing threat because of the shrinking arsenal of efficacious antibiotics. Now researchers from the University of Colorado Boulder, USA, have shown that photoexcited quantum dots (QDs) made from materials including CdTe and CdSe can kill a wide range of multidrug-resistant bacteria.
These include methicillin-resistant Staphylococcus aureus, carbapenem-resistant E-coli, and extended-spectrum Î²-lactamase-producing Klebsiella pneumoniae and Salmonella typhimurium.
"By shrinking these semiconductors down to the nanoscale, we're able to create highly specific interactions within the cellular environment that only target the infection," said Prashant Nagpal, an assistant professor in the Department of Chemical and Biological Engineering at CU-Boulder and one of the authors of the study.
Previous research has shown that metal nanoparticles-created from gold and silver, among other metals-can be effective at combating antibiotic resistant infections, but can indiscriminately damage surrounding cells as well.
The quantum dots, however, can be tailored to particular infections thanks to their light-activated properties. The dots remain inactive in darkness, but can be activated on command by exposing them to light, allowing researchers to modify the wavelength in order to alter and kill the infected cells.
"While we can always count on these superbugs to adapt and fight the therapy, we can quickly tailor these quantum dots to come up with a new therapy and therefore fight back faster in this evolutionary race," said Nagpal.
'Photoexcited quantum dots for killing multidrug-resistant bacteria' By Colleen M. Courtney, Samuel M.Goodman et al; Nature Materials (2016)