Painting A Picture Of Wound Oxygenation

Tracking oxygenation levels in a wound allows doctors to monitor a patient’s healing. But dealing with damaged tissue requires a delicate touch. Many existing methods measure skin oxygenation; however, most of them are invasive. Researchers led by Conor L. Evans of Harvard Medical School and Massachusetts General Hospital have worked around that limitation by developing a bandage that can be painted atop a wound to map tissue oxygen content and consumption (Biomed. Opt. Express 2014, DOI: 10.1364/boe.5.003748). The team imbued a commercial liquid bandage solution with an oxygen-sensitive phosphorescent porphyrin dendrimer called Oxyphor R2. The porphyrin’s dendritic arms helped the team control oxygen flux to the molecule’s phosphorescent core and also kept the molecules dispersed throughout the liquid. The researchers painted bandages onto wounds, where they cured into flexible dressings. Measuring variations in the intensity or in the lifetime of the phosphorescent signal over a bandage’s surface allows the team to map the oxygenation of the tissue underneath. Although the team says the sensitivity of its bandage can be improved, few existing oxygen monitors can be applied—or peeled off—so painlessly.