Rapid Fire Presentations
558: In Vitro pO2 Measurement of Islet Encapsulation Devices in Oxygen Measurement Core
(In collaboration with the University of Chicago, University of Arizona, Cornell University, University of Florida, and McGill University)
This work is the outcome of JDRF-supported “Oxygen Measurement Core” facility established at O2M Technologies. We performed in vitro and in vivo pO2 measurements of acellular and cell loaded islet cell transplantation devices originated from the core members' labs. These devices varied in shape, size, biomaterials, and oxygen profile. We will present key data from these measurements.
559: Trityl Radical OX071, an EPR Oxygen Imaging Spin Probe, Is Non-Toxic to Cells
(In collaboration with the University of Chicago)
Our experimental results using many different cell types showed that trityl OX071, the oxygen reporting molecule for electron paramagnetic resonance oxygen imaging is non-toxic to cells, suggesting it can be used as an in vitro or in vivo spin probe for pO2measurements in cell-based therapies.
560: Methodology for Biomaterial Oxygen Imaging Using Trityl Based Pulse Electron Paramagnetic Resonance
(In collaboration with the University of Chicago)
Oxygen is an important indicator of the physiologic state of tissues and bioartificial devices. Although oxygen point measurements using polarographic needle electrodes or luminescence-based optical sensors can reveal local oxygenation, three-dimensional oxygen maps deliver the complete information and thus can better assist the development of artificial cell and tissue replacement devices. This is especially important for samples where metabolically active cells can create steep oxygen gradients on the scale of hundreds of microns. For optically opaque samples magnetic resonance methods are found to be the most suitable. Pulse electron paramagnetic resonance oxygen imaging (EPROI) is an emerging technique to provide three-dimensional partial oxygen pressure (pO2) maps of tissues and biological samples.
340: Synergistic Effect of Placental Membrane Extract and Hypoxia on Human Adipocyte Differentiation
(In collaboration with University of Illinois College of Medicine Rockford)
One of the major drawbacks associated with autologous fat grafting is unpredictable graft retention. With a potential volume loss of 30-70% at one year, identifying methods to improve graft survival are relevant. Each step along the way, i.e., harvesting, processing, and transplantation have opportunities to impact the success of this procedure. Our synthesized Gtn-FA hydrogel crosslinked with laccase effectively produces a hypoxic environment as validated by EPROI. Gene expression data showed that key gene markers for differentiation and angiogenesis were significantly upregulated compared to baseline, further validating the efficacy of ACM supplementation as a novel way to promote adipocyte survival and retention.
