Boron Dye-Polymer Materials for Oxygen Sensing and Imaging

Bioimaging based on luminescence has brought revolutionary advancement in studying biology and biomedicine. The family of difluoroboron beta-diketones (BF2bdks) dye polymeric materials has been widely used as imaging and sensing reagents. These materials possess unique dual-emissive properties, that is, fluorescence (F) and oxygen sensitive room temperature phosphorescence (RTP), making them ideal for ratiometric oxygen sensing where the fluorescence serves as an internal standard and the phosphorescence is the oxygen sensor. The properties including emission, lifetime, and oxygen sensitivity are tunable by boron dye modification and polymer conjugation, which provides a wide range of potential biological applications for the dye polymer materials. The material behaviors in relevant biological environment are studied, and material engineering and optimization for multiple biological purpose are discussed. First, the blue boron nanoparticles were optimized as cell tracking reagents in immunology. Second, active targeting was achieved by appropriate surface modification with biomolecules to improve delivery and tumor accumulation. For example, folic acid was conjugated to fabricate multi-color and oxygen sensing nanoparticles. Then, new oxygen sensing dyes were designed to be used with red/green/blue (RGB) color camera, and their utilities were demonstrated in murine wound oxygen imaging. Finally, oxygen sensing method was established to study oxygen consumption and brain activity in the brain slices.