1 October 2014. Researchers at Massachusetts General Hospital in Boston developed a paint-on covering for severe wounds that changes color to indicate the extent of healing taking place. The team from the lab of Conor Evans in Mass. General’s photomedicine center published its findings in today’s issue of Biomedical Optics Express, published by the Optical Society.
The Evans team — including colleagues from Harvard Medical School, affiliated hospitals, U.S. Army, and institutions in Germany and Korea — sought a technique for non-invasively monitoring healing progress of severe wounds, such as burns and ischemic wounds, where blood flow to the injury is blocked. Chronic wounds of this kind, including those caused by combat, are estimated to affect 6.5 million people in the U.S., leading to some $25 billion in health care costs each year.
The bandage technology measures the extent of oxygen concentration in the wound area, an indicator of the extent of healing. It uses porphyrin-dendrimer materials, called Oxyphor R2 made by Oxygen Enterprises in Philadelphia, that give off a phosphorescent glow in the presence of oxygen. The bandage compound also has a green dye that acts as a baseline reference and with which clinicians can measure the extent of healing as it changes to red.
The bandage is painted on the wound as a viscous liquid using as its base New-Skin liquid bandage, an over-the-counter product made by Prestige Brands that dries to a solid film. A transparent barrier layer is then applied over the film to keep out ambient air, thus responding to oxygen concentrations generated as a result of the healing process.
The third part of the technology is a camera-like device that first gives off light to excite the phosphors in the porphyrin-dendrimer materials, and then measures the light emissions from the bandage. Zongxi Li, a research fellow in Evans’s lab and first author of the paper, says in an Optical Society statement that the camera can be configured to “measure either the brightness or color of the emitted light across the bandage or the change in brightness over time.”
The researchers tested proof-of-principle technology to measure burn healing in lab rats and pigs, as well as a monitor for healing of skin grafts with pigs. The lab plans to extend the bandage’s sensory capabilities to other healing indicators such as pH and bacterial load, as well as adapting the technology to on-demand release of drugs.
Evans and colleagues are seeking industry partners to bring the technology to market. One potential application is hand-held or smartphone-based field devices, since the light emitted from the bandage is bright enough to be read by those systems.
Read more:
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- Patent Granted for RNA-Interference to Treat Scar Tissue
- Early Human Trial Tests Ultrasound to Heal Venous Ulcers
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