Publications [#196426] of Bruce M. Klitzman

Papers Published

1. HL Prichard, T Schroeder, WM Reichert, B Klitzman, Bioluminescence imaging of glucose in tissue surrounding polyurethane and glucose sensor implants., Journal of diabetes science and technology, vol. 4 no. 5 (September, 2010), pp. 1055-62, ISSN 1932-2968
   (last updated on 2011/10/31)

   Abstract:
   BACKGROUND: The bioluminescence technique was used to quantify the local glucose concentration in the tissue surrounding subcutaneously implanted polyurethane material and surrounding glucose sensors. In addition, some implants were coated with a single layer of adipose-derived stromal cells (ASCs) because these cells improve the wound-healing response around biomaterials. METHODS: Control and ASC-coated implants were implanted subcutaneously in rats for 1 or 8 weeks (polyurethane) or for 1 week only (glucose sensors). Tissue biopsies adjacent to the implant were immediately frozen at the time of explant. Cryosections were assayed for glucose concentration profile using the bioluminescence technique. RESULTS: For the polyurethane samples, no significant differences in glucose concentration within 100 μm of the implant surface were found between bare and ASC-coated implants at 1 or 8 weeks. A glucose concentration gradient was demonstrated around the glucose sensors. For all sensors, the minimum glucose concentration of approximately 4 mM was found at the implant surface and increased with distance from the sensor surface until the glucose concentration peaked at approximately 7 mM at 100 μm. Then the glucose concentration decreased to 5.5-6.5 mM more than 100 μmm from the surface. CONCLUSIONS: The ASC attachment to polyurethane and to glucose sensors did not change the glucose profiles in the tissue surrounding the implants. Although most glucose sensors incorporate a diffusion barrier to reduce the gradient of glucose and oxygen in the tissue, it is typically assumed that there is no steep glucose gradient around the sensors. However, a glucose gradient was observed around the sensors. A more complete understanding of glucose transport and concentration gradients around sensors is critical.

   Keywords:
   Animals • Biological Transport • Biopsy • Biosensing Techniques • Glucose • Implants, Experimental* • Luminescence* • Male • Models, Animal • Oxygen • Polyurethanes* • Rats • Rats, Inbred Lew • Skin • Stromal Cells • analysis • analysis* • chemistry* • cytology • instrumentation* • metabolism • methods • pathology • physiology