Compositions and methods for making and using oxygen sensing nanofibers and scaffolds

Abstract

To address the need for scaffold-based oxygen concentration monitoring, a single-component, self-referenced oxygen sensor was made into nanofibers. Electrospinning process parameters were tuned to produce a biomaterial scaffold with specific morphological features. The ratio of an oxygen sensitive phosphorescence signal to an oxygen insensitive fluorescence signal was calculated at each image pixel to determine an oxygenation value. A single component boron dye-polymer conjugate was chosen for additional investigation due to improved resistance to degradation in aqueous media compared to a dye polymer blend. Standardization curves show that in fully supplemented media, the fibers are responsive to dissolved oxygen concentrations less than 15 parts per million. Spatial and temporal ratiometric gradients were observed in vitro radiating outward from the center of a dense adherent cell grouping. Sensor activation in ischemia and cell transplant models in vivo show oxygenation decreases on the scale of minutes.