Antibiotic-resistant bacteria such as Salmonella, E. Coli and Staphylococcus infect some two million people and kill at least 23,000 people in the US each year. Efforts to thwart these 'superbugs' have consistently fallen short due to the bacteria’s ability to rapidly adapt and develop immunity to common antibiotics such as penicillin.
New research by scientists from CU-Boulder, however, suggests that the solution to this big global problem might be to think small – very small.
In findings published in the journal Nature Materials, researchers at the Department of Chemical and Biological Engineering and the BioFrontiers Institute describe new light-activated therapeutic nanoparticles known as 'quantum dots'. The dots, which are about 20,000 times smaller than a human hair and resemble the tiny semiconductors used in consumer electronics, successfully killed 92% of drug-resistant bacterial cells in a lab-grown culture.
'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 a senior author 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 also indiscriminately damage surrounding cells.
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
The quantum dots, however, can be tailored to particular infections owing 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 to alter and kill the infected cells.
The specificity of this innovation may help reduce or eliminate the potential side effects of other treatment methods, as well as provide a path forward for future development and clinical trials.
Nagpal and Anushree Chatterjee, an assistant professor in the Department of Chemical and Biological engineering at CU-Boulder, are the co-founders of PRAAN Biosciences, a Boulder, Colorado-based startup that can sequence genetic profiles using a single molecule, technology that may aid in the diagnosis and treatment of superbug strains. The authors have filed a patent on the new quantum dot technology.
The new study was co-authored by Colleen Courtney, Samuel Goodman and Jessica McDaniel, all of the Department of Chemical and Biological Engineering at CU-Boulder; and Nancy Madinger of the University of Colorado Anschutz.
The W M Keck Foundation and the National Science Foundation supported the research.
