Dr. Joseph. C. Wu and colleagues used microPET imaging technology and a special optical bioluminescent cooled charge coupled device (CCD) camera to monitor the survival of transplanted rat cardiac cells within the myocardium – the middle layer of the wall of the heart composed of cardiac muscle fibers that allow the heart to contract – of living rats. Forty rats were injected with H9C2 cells and a control group of ten rats were only injected with saline. MicroPET (using [18F]-FHBG as reporter probe) and optical CCD (using D-Luciferin) images were acquired.
The results of the study, which were presented at the Society of Nuclear Medicine’s 50th Annual Meeting, revealed that microPET detected significantly higher [18F]-FHBG uptake in the area where cells had been transplanted compared to background uptake in other parts of the myocardium that did not receive transplant and compared to the control rats. This indicated the presence and location of viable transplanted cells. Similar results were duplicated using optical CCD imaging. Importantly, in vivo imaging results were also confirmed by ex vivo autoradiography, histologic staining and immunohistochemistry.
Although this is the first study to monitor cardiac cell transplant using both microPET and optical CCD imaging, the researchers believe that “understanding the real-time physiologic state of engrafted cells should add further insight into cell transplant biology.”