The nanotube-enzyme approach is likely to prove superior to previous attempts at antimicrobial agents, which fall into two categories: coatings that release biocides, or coatings that "spear" bacteria.
Coatings that release biocides which work in a manner similar to marine anti-fouling paint pose harmful side-effects and lose effectiveness over time as their active ingredient leaches into the environment.
Coatings that spear bacteria using amphipatic polycations and antimicrobial peptides tend to clog, also losing effectiveness.
The nanotube-lysostaphin coating does neither, said Dordick.
"We spent quite a bit of time demonstrating that the enzyme did not come out of the paint during the antibacterial experiments. Indeed, it was surprising that the enzyme worked as well as it did while remaining embedded near the surface of the paint," Dordick said.
The enzyme's slicing or "lytic" action also means that bacterial cell contents disperse, or can be removed by rinsing or washing the surface.
Kane also said MRSA are unlikely to develop resistance to a naturally occurring enzyme.
"Lysostaphin has evolved over hundreds of millions of years to be very difficult for Staphylococcus aureus to resist," Kane said. "It's an interesting mechanism that these enzymes use that we take advantage of."
|Contact: Mary Martialay|
Rensselaer Polytechnic Institute