Microfluidic wound bandage: localized oxygen modulation of collagen maturation

Restoring tissue oxygenation has the potential to improve poorly healing wounds with impaired microvasculature. Compared with more established wound therapy using hyperbaric oxygen chambers, topical oxygen therapy has lower cost and better patient comfort, although topical devices have provided inconsistent results. To provide controlled topical oxygen while minimizing moisture loss, a major issue for topical oxygen, we have devised a novel wound bandage based on microfluidic diffusion delivery of oxygen. In addition to modulating oxygen from 0 to 100% in 60 seconds rise time, the microfluidic oxygen bandage provides a conformal seal around the wound. When 100% oxygen is delivered, it penetrates wound tissues as measured in agar phantom and in vivo wounds. Using this microfluidic bandage, we applied the oxygen modulation to 8 mm excisional wounds prepared on diabetic mice. Treatment with the microfluidic bandage demonstrated improved collagen maturity in the wound bed, although only marginal differences were observed in total collagen, microvasculature, and external closure rates. Our results show that proper topical oxygen can improve wound parameters underneath the surface. Because of the ease of fabrication, the oxygen bandage represents an economical yet practical method for oxygen wound research.