Guelph, ON – A Canadian scientist is developing new filters that, instead of simply relying on small pores to block contaminants, actively remove unwanted components. Dr Chris Hall, of the University of Guelph’s department of environmental biology, is making filters from protein-enhanced paper to detect and capture harmful particles.
The specialized filters could be used to 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 Dr Hall.
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.
He says the protein’s CBD will be borrowed from enzymes that normally bind to cellulose and degrade it. Then, using molecular biology tools, the professor 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. For example, a SARS-fighting antibody could be linked to paper through a CBD. This paper could then be used to supply healthcare workers with SARS masks that prevent them from inhaling the virus by trapping it first, he says.
Dr Hall 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.
He says he 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. “Paper can be used to do just about anything,” he says. “What we really want to do is build a platform for rapidly detecting pathogens by optimizing its use.”