They may not be pretty, but scabs are essential for the proper healing of wounds. An advanced new bandage mimics human scab formation, promoting faster wound healing with an artificial membrane that engages the body's natural defenses.
Researchers working with Shutao Wang at the Chinese Academy of Sciences in Beijing were impressed by the human body's natural ability to close wounds with scabs, the hard reddish-brown globs that form to prevent continuous bleeding, protect underlying tissue from infection-causing germs, and draw out new cells that help repair injured skin.
Commonly used bandages, like Band-Aids, can protect against bleeding and infections, but don't do much to speed up healing.
More cutting-edge wound dressing materials, like hydrogels and nanofibers, may be more effective at fighting off pathogens and stanching blood flow than Band-Aids, but Wang's team found their ability to accelerate healing to be lacking.
Wang's team wanted to more directly mimic scab formation, with bandages that protecting open wounds while actively helping them heal.
The researchers wove flexible nano-scale fibers of polyurethane plastic into a pattern that mimics the dense underside of scabs, which have tiny fibers arranged in the same direction.
The resulting "cytophilic" membrane, described in a paper in the journal ACS Applied Materials & Interfaces, helps repair open wounds by attracting new cells from the bloodstream that speed up the natural healing process.
Lab experiments on rats showed that healing cells like fibroblasts and epithelial cells rapidly attached to the cytophilic membrane and arranged in dense patterns, much like those in real scabs.
The material mimics human scab formation, promoting faster wound healing with a nanofiber membrane that draws out the body's healing cells.
The scientists see great medical potential for their advanced polyurethane bandages.
Among other biological uses, they concluded in their paper that the membranes might be useful in the "fabrication of dressing materials for rapid wound healing, as well as other biomaterials, such as membranes for the capture of circulating tumor cells, bone growth, and construction of a neural network."
Source: Xi Y, Dong H, Sun K, et al. Scab-Inspired Cytophilic Membrane of Anisotropic Nanofibers for Rapid Wound Healing. ACS Applied Materials & Interfaces, 2013.