Green tea + salt = antibacterial coating
Researchers at Northwestern University have discovered new ways of utilizing the properties of naturally occurring polyphenols found in green tea, red wine and dark chocolate. Dissolving polyphenol powders in water with a small amount of salt instantly produces transparent coatings that kill bacteria on contact, have antioxidant qualities and are non-toxic. The sticky nature of polyphenols and the low cost of materials could open the door to a wide range of uses for these coatings.
Apparently the coatings can stick to virtually any surface, even Teflon, and are only 20 to 100 nanometers thick, potentially making them ideal for use in a whole range products…
Polyphenols are naturally occurring molecules found in many plants that also give some flowers, fruits, and vegetables their color. They are antioxidants that can reverse problems caused by oxidative stress to artery walls and their anti-inflammatory properties are said to help relieve chronic pain in conditions like rheumatoid arthritis.
Furthering their research, Professor Phillip Messersmith and his team experimented with dipping various objects into saline solutions of tannic acid or pyrogallol, with similar results but at a much lower cost and with even faster results. They went on to test “medically relevant polymers, engineering polymers, metals, inorganic substrates and ceramics,” with the same success. They were also able to modify the coatings enabling additional functions without affecting the original properties. In one experiment they succeeded in adding an anti-fouling element to the coating which would make it ideal for applying to pacemakers to prevent the buildup of cells on its surface.
“The coatings innately have properties that are very beneficial to saving lives and keeping people healthy,” says Tadas S. Sileika, a graduate student in Messersmith’s lab and first author of the paper detailing the research. “Without any further modification, they can help prolong the life of a medical device, reduce inflammation in a patient and prevent bacterial infections.”
Bravo! That last step from anecdotal success at treating ailments and disease with natural compounds has always been difficult. Not the least of which is that tales of success often are magnified in memory and retelling.
Another new area of research truly worth following.