Researchers at the University of Calgary have teamed up with an Alberta-based company to turn limestone into a long-lasting antimicrobial agent, a discovery that could help to cut the spread of harmful bacteria and fungi in food and health-care settings.
The partnership with Biosenta Inc. includes the Schulich School of Engineering and the Alberta Centre for Advanced Diagnostics (ACAD) in the Faculty of Science.
"The idea started with a simple question: Could a basic mineral - limestone - be reimagined to fight harmful pathogens?" says Dr. Maen Husein, PhD, a professor in the Department of Chemical and Petroleum Engineering at UCalgary.
"We are proving there is enormous untapped potential in a rock most of us take for granted."
Tiny shell protects active ingredient
Researchers have been able to develop a "shell and core" nanoparticle.
"The tiny shells' protect the active ingredient - calcium hydroxide - far longer than anything you see with conventional disinfectants," Husein explains.
Future applications of the technology are still being determined, but the researchers say there's potential to use it anywhere that needs to control the growth of dangerous pathogens.
New technology tested against pathogens that cause bloodstream infections
Dr. Mehdi Mohammed Ashani, PhD, a research associate in the Department of Biological Sciences who works as a senior scientist for Biosenta, says the team had to develop a new microbiology technique to study the antimicrobial effectiveness and long-term stability of the nanoparticles.
"This approach was applied against a wide range of pathogens as well as fungi, E. coli, Staphylococcus aureus (bacteria), and Candida albicans (fungus), all of which are known to cause bloodstream infections."
Noora Darwish, who recently defended her PhD in Chemical and Petroleum Engineering, says it's been challenging - and worthwhile - work.
She and the rest of the team have published research papers related to the product and its processes.
The first paper Controlled carbonation of Ca(OH)2 surface and its application as an antibacterial particle published in ScienceDirect, confirmed its superior antibacterial properties. The second, Synthesis of uniform core-shell calcium hydroxide-calcium carbonate biocidal particles via encapsulation into dry ice published in March in the Canadian Journal of Chemical Engineering, offers a new method to produce nanoparticles and measure antibacterial activity against bacteria.
Company's donation stems from personal loss
The research is sponsored by Biosenta Inc. as well as Mitacs Accelerate and NSERC Alliance.
Biosenta CEO and UCalgary alumnus Am Gill, BComm 97, says he wanted to make a difference with his company's donation.
"This mission is personal for me," says Gill. "I lost my uncle to a hospital-acquired infection, a preventable tragedy that inspired my commitment to supporting science and innovation."
Dr. Ian Lewis, PhD, director of ACAD, says the company's contribution is important to the research.
"This donation is enabling ongoing work on innovative technology to create new generations of nanoparticles with antimicrobial activity," he says. "It supports professional scientists who are working to apply this technology to areas that affect human health."
ACAD specializes in harnessing technology to understand and control the spread of infections.
"We have contributions from our colleagues in the Cumming School of Medicine, Schulich School of Engineering and others," says Lewis.
He notes that the centre was meant to facilitate interdisciplinary work.
"When you combine engineering innovations with microbiology testing you can bring transformative ideas to life that improve the world around us" adds Husein, "and that is exactly what is happening here at the University of Calgary."
Some of the antibacterial products being developed include:
Concrete
Enhances structural durability while inhibiting microbial growth, which could be valuable in high-traffic public spaces.
Paint
Combats hospital-acquired infections by preventing bacterial growth on walls and other surfaces in health-care settings, daycares and schools.
Coating
Reduces contamination risks in food packaging and surfaces such as handrails and touchscreens. Could be used in public transportation, schools, daycares and offices where hygiene is critical.
