Those melt-on-your-tongue mouthwash strips on sale at the grocery checkout don’t just zap your foul-smelling pizza breath — it turns out they have spawned potentially life-saving public-health innovations, too.
Scientists with the Biointerfaces Institute at McMaster University are using a compound found in the breath-freshening film to create what they say is a simpler, more cost-effective method of administering vaccines in low-income countries.
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Carlos Filipe, the lead researcher on the project, says he hopes the tabs his team has developed will eliminate the need to refrigerate vaccines while they’re being transported or stored overseas.
“About 80 per cent of the cost of vaccination is around distribution,” said Filipe, a professor of chemical engineering who specializes in molecular biology. “But we are trying to get around that.”
The group has been awarded a $100,000 grant from Grand Challenges Canada, a federally funded body that sponsors researchers working in global health, to test and further fine-tune the invention.
'Like making Jell-O'
Typically, vaccines contain genetic material from the viruses or bacteria — like polio or diphtheria, for example — that they’re designed to combat. But currently, most vaccines need to be refrigerated so their active ingredients don’t deteriorate.
This is a problem in parts of the developing where electricity service isn’t very reliable, Filipe said. “If you think of a place like India where there are more power outages, and you keep a vaccine in the refrigerator, you never know how much of it still remains active.”
However, the McMaster team found they could preserve live vaccines at room temperature by infusing them into a mixture containing pullulan, an edible polymer that’s found in breath strips. Derived from a common type of fungus, this compound normally rests in a solid state but dissolves rapidly in water.
Creating the film “is very much like making Jell-O,” said Filipe. “You add an enzyme into the solution, you add a powder and it forms a film. So essentially, all of the biological molecules are entrapped, like a pudding.”
This isn’t the first time the Biointerfaces Institute has applied breath-strip technology to address a common global-health problem. Earlier this year, the scientists unveiled a pullulan-based pill designed to test for the presence of a number of pollutants — including certain pesticides, metals and E. Coli — in drinking water. (It causes water to turn colour if contaminants are present).
Filipe said Sana Jahanshahi-Anbuhi, a McMaster PhD student who studies chemical engineering, came up with the idea to apply breath-strip technology to water testing.
“She was looking for a paper-based sensor that would detect pesticides in water, and she wanted to find a polymer that would dissolve in water very rapidly,” he said.
Pullulan worked well as a delivery mechanism for a concoction that detects certain pesticides, but the researchers then discovered they could use a single strip to test for different kinds of contaminants.
“For a variety of reasons, it stabilizes the enzymes, so it prevents them from degrading with temperature and stops them from rubbing against each other and forming like a cake,” Filipe said.
Months of testing ahead
Armed with the Grand Challenges Canada grant, Filipe’s group is set to spend much of the next year studying the vaccine project further. Vaccine-loaded tabs will be stored at a variety of temperatures — up to 40 C — and then administered to lab mice.
“And then we’ll expose the animal the infectious agent” to see whether the vaccine held up, Filipe explained.
“If that works, then it means you pretty much cover all potential real conditions.”