- Monash University researchers have discovered how nanoparticles could develop a biosensor to prevent deadly diseases in medical equipment such as catheters.
- Candida Albicans can become a serious problem for severely ill or immunosuppressed people.
Monash University researchers have gained insight into how nanoparticles could be used to identify the presence of invasive and sometimes deadly microbes, as well as to offer targeted treatments more effectively.
This study was conducted as an interdisciplinary collaboration between microbiologists, immunologists and engineers led by Dr. Simon Corrie of the Department of Chemical Engineering at Monash University and Professor Ana Traven of the Monash Biomedicine Discovery Institute (BDI). It was recently published in the journal American Chemical Society Interfaces and materials applied to ACS.
Candida Albicans, a commonly encountered microbe, can become deadly when it colonizes devices such as catheters implanted in the human body. Although commonly found in healthy people, this microbe can become a serious problem for those who are severely ill or immunosuppressed.
The microbe forms a biofilm when it colonizes using, for example, a catheter as a source of infection. It then spreads into the bloodstream to infect internal organs.
“The mortality rate in some patient populations can be as high as 30 to 40 percent, even if you treat people. When it colonizes, it is highly resistant to antifungal treatments, ”said Professor Traven.
“The idea is that if you can diagnose this infection early, you may have a much better chance of successfully treating it with current antifungal drugs and stopping a total systemic infection, but our current diagnostic methods are missing. A biosensor to detect early stages of colonization would be highly beneficial. "
The researchers investigated the effects of organosilic nanoparticles of different sizes, concentrations and surface coatings to see if and how they interacted with them. C. albicans and with immune cells in the blood.
They found that nanoparticles bound to fungal cells but were not toxic to them.
"They don't kill the microbe, but we can create an antifungal particle by binding it to a known antifungal drug," said Professor Traven.
The researchers also demonstrated that the particles associate with neutrophils – human white blood cells – in a similar way to C. albicansremaining non-cytotoxic to them.
"We have identified that these nanoparticles, and by inference many different types of nanoparticles, can be made to be interactive with cells of interest," said Corrie.
“We can actually change surface properties by attaching different things; so we can actually change the interactions they have with these cells – that's quite significant. "
Corrie said that while nanoparticles were being investigated in cancer treatment, the use of nanoparticle-based technologies in infectious diseases lags behind the nanomedicine field, despite the great potential for new treatments and diagnostics.
"The other unique thing about this study is that instead of using cultured cells, we are also seeing how the particles act on whole human blood and neutrophils extracted from fresh human blood," he said.
Professor Traven said the study benefited greatly from interdisciplinary collaboration.
"We have combined laboratories with expertise in infection, microbiology and immunology with a laboratory with engineering expertise to conduct cutting-edge experiments," she said.
First author of the study, Ph.D. Student Vidhishri Kesarwani, co-supervised by Dr. Corrie and Professor Traven, crossed disciplinary boundaries in a highly effective manner and was instrumental in the study. Professor Stephen Kent, from the Department of Microbiology and Immunology at the University of Melbourne, developed the assays to investigate the association between nanoparticles and immune cells in fresh human blood.
Read the full article at Interfaces and materials applied to ACS, Characterization of the main bio-nano interactions between organosilic nanoparticles and Candida Albicans.