University of Virginia Patent Foundation

Cassandra L Fraser

Guoqing Zhang

Kenneth Brayman

Edward A Botchwey, Iii

Daniel Bowers

Jianbin Chen

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.

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

The invention provides luminescent solid-state compositions comprising difluoroboron beta-diketonates wherein the compositions can exhibit mechanochromic luminescence. The mechanochromic effect on the luminescence can be reversible, such as thermally reversible. Various solid-state forms of the invention can have emission spectra that differ from the properties of the respective difluoroboron beta-diketonate in solution. The mechanochromic effect can be stimulated by pressure such as handwriting, and can be reversed over a period of minutes to hours at room temperature. The invention also provides methods of making and methods of using the solid-state compositions, such as for sensors and for information displays for use in biological sensing, and in art, design, and consumer products. Compositions of the invention, such as compositions in nanoparticulate form, or contained within a matrix material, can be used in conjunction with fluorescence microscopy to provide information concerning pressures and tensions within and external to living cells, tissues, or organisms.

Mechanochromic luminescent difluoroboron beta-diketonates

The present invention provides in one aspect polymeric luminescent dye compounds having fluorescent properties, phosphorescent properties, or both fluorescent and phosphorescent properties.

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Charlottesville, VA, United States of America

Cassandra L Fraser