Imbed Biosciences received clearance from the Food and Drug Administration to market its patented wound dressing for human use. The Microlyte Ag is a sheet as thin as Saran Wrap and can conform to the bumps and crevices of a wound, said company CEO Ankit Agarwal.
The dressing is now cleared by the FDA as a class II medical device, for prescription and over-the-counter use.
Like many dressings now used to treat burns and other persistent wounds, Microlyte Ag contains silver to kill bacteria — but in much smaller quantities.
“Silver is an excellent antimicrobial agent,” Agarwal said. “It is active against a broad range of bacteria and yeast. But the large silver loads found in conventional silver dressings can be toxic to skin cells. Our dressing uses as little as 1 percent as much silver as the competition, and yet the tests we submitted to the FDA showed that Microlyte kills more than 99.99 percent of bacteria that it contacts.”
That kill ratio even appeared in tests against some of the nastiest hospital-acquired superbugs, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococcus.
Imbed’s Microlyte dressing is applied to a wound on a pig. The ultra-thin dressing conforms to the wound, bringing the antimicrobial silver into direct contact with bacteria. (Credit: University of Wisconsin-Madison)
Microlyte overcomes a key problem with existing dressings: stiffness. Under a low-power microscope, a wound has bumps and fissures — hiding places for bacteria. The Microlyte dressing inherently adheres to moist surfaces and is so flexible that it drops into the fissures, leading to the sweet combination of greater destruction of bacteria at much lower doses of silver.
Microlyte has several other advantages, Agarwal said. It retains moisture yet is ultrathin and breathable, allowing oxygen to reach the wound and gases to exit, all factors that promote healing. The slow release of the silver means the dressing can remain in place for at least one day. And because the material is a hydrogel (a water-based gel), it can simply be rinsed off as needed before replacement.
Experience with animals shows that the ultra-thin dressing simply sloughs off as the wound heals. All of these advantages should reduce the need to change dressings, which can be so painful that sedation is needed, especially for children.
