Readership Survey
Researchers use protein-enhanced paper in effort to create advanced filters that actively remove contaminants, not just block them
BY ROBERT FIELDHOUSE SPARK PROGRAM
New filters being developed from protein-enhanced paper that can detect and capture harmful particles have a strong potential to improve Canadians' health and safety, says Prof. Chris Hall, Environmental Biology.
The specialized filters he and his collaborators are creating could be used to actively remove water contaminants, purify disease-causing antigens for medical research, prevent undesirable agents from entering emergency blood supplies, protect citizens from bioterrorists and filter air in cars.
“The real difficulty is getting whatever it is that binds to pathogens to bind to paper, too,” says Hall.
Current filters rely mostly on small pores that block contaminants from passing through based on their size, he says. But now the goal is to create advanced filters that will actively remove unwanted components in a variety of situations.
Most filters are based on cellulose, a carbohydrate that's the main component in paper. The new filters will feature special proteins that stick to cellulose. The proteins will have two parts: one called a cellulose binding domain (CBD) to bind cellulose, and the other an antibody to bind pathogens and other contaminants.
Hall says the protein's CBD will be borrowed from enzymes that normally bind to cellulose and degrade it. Then, using molecular biology tools, he and his team will create “fusion proteins” that replace the degrading component with an antibody that recognizes and fuses to harmful agents, anchoring them to the filter surface and preventing them from passing through the paper's pores.
This type of filtering goes beyond just using size to exclude undesirable materials, says Hall. For example, a SARS-fighting antibody could be linked to paper through a CBD. This paper could then be used to supply health-care workers with SARS masks that prevent them from inhaling the virus by trapping it first.
He is investigating antibodies designed to capture and detect several bacteria species, including E. coli and Pythium. His first test will be to see whether his fusion proteins can be applied to water filters that specifically target these organisms that cause human or plant diseases.
This five-year project is still in its early stages, with preliminary results just beginning to flow in. By the project's end, Hall hopes it will be possible to print his fusion proteins onto paper to create the novel filters and other similar products. He says paper is perfect for many applications because it's inexpensive, disposable and can be made sterile.
“It's absolutely amazing. Paper can be used to do just about anything. What we really want to do is build a platform for rapidly detecting pathogens by optimizing its use.”
Others involved in this project are Prof. Mansel Griffiths, Food Science; Prof. Stephen Seah, Molecular and Cellular Biology; research associate Michael McLean and graduate students Greg Hussack, Melissa Bassoriello and Sarah Wood, Environmental Biology; and Roger MacKenzie, National Research Council.
This research is sponsored by the Ontario Ministry of Agriculture, Food and Rural Affairs, the Natural Sciences and Engineering Research Council, the SENTINEL Network and its industry partners.
