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The long term goal of this research is to use cryo-imaging to detect and spatially map nearly every stem cell in a mouse and quantify tissue specific, cell therapy PK. With this enabling technology, one will be able to quantitatively assess specificity of homing, quiescent survival in specific niches, emerging homing factors, delivery processes, cell engraftment dose response, etc., analyses which have, at best, been done qualitatively. To this end, we developed a cryo-imaging system, which alternates between sectioning (10-40 µm) and imaging bright field and fluorescence block-face image volumes with micron-scale-resolution. For applications requiring single-cell detection of fluorescently labeled cells anywhere in a mouse, we developed an algorithm, next-image processing, for reduction of subsurface fluorescence. Next-image processing greatly improves axial-resolution, enabling high quality 3D volume renderings, and improved automated enumeration of single cells by up to 24%. To answer many of the pressing questions in stem cell therapies, automated methods for quantification and detection of stem cells are required. We developed algorithms for the automated detection and quantification of fluorescently labeled cells. Our model based quantification algorithm was performed on low resolution images of fluorescently labeled stem cells and the results were compared to visual quantification of stem cells in high resolution images. In all cases but two, the algorithm was within ± 1 cells of the actual number present in a cluster. The total number of cells counted by the expert was 393 compared to 386 by the algorithm, giving an error rate of 1.7%. To estimate homing of stem cells to damaged tissues, quantification of stem cells in infracted mice hearts was compared to non-infarcted control mice hearts. The number of MSC’s detected in the heart was significantly higher for infarcted mice. The delivery ratio for infarcted mice was 8.0 ± 0.8 times larger than the delivery ratio for a control mouse on Day 4. This suggests that stem cells were homing to the damaged myocardium.

The long term goal of this research is to use cryo-imaging to detect and spatially map nearly every stem cell in a mouse and quantify tissue specific, cell therapy PK. With this enabling technology, one will be able to quantitatively assess specificity of homing, quiescent survival in specific niches, emerging homing factors, delivery processes, cell engraftment dose response, etc., analyses which have, at best, been done qualitatively. To this end, we developed a cryo-imaging system, which alternates between sectioning (10-40 µm) and imaging bright field and fluorescence block-face image volumes with micron-scale-resolution. For applications requiring single-cell detection of fluorescently labeled cells anywhere in a mouse, we developed an algorithm, next-image processing, for reduction of subsurface fluorescence. Next-image processing greatly improves axial-resolution, enabling high quality 3D volume renderings, and improved automated enumeration of single cells by up to 24%. To answer many of the pressing questions in stem cell therapies, automated methods for quantification and detection of stem cells are required. We developed algorithms for the automated detection and quantification of fluorescently labeled cells. Our model based quantification algorithm was performed on low resolution images of fluorescently labeled stem cells and the results were compared to visual quantification of stem cells in high resolution images. In all cases but two, the algorithm was within ± 1 cells of the actual number present in a cluster. The total number of cells counted by the expert was 393 compared to 386 by the algorithm, giving an error rate of 1.7%. To estimate homing of stem cells to damaged tissues, quantification of stem cells in infracted mice hearts was compared to non-infarcted control mice hearts. The number of MSC’s detected in the heart was significantly higher for infarcted mice. The delivery ratio for infarcted mice was 8.0 ± 0.8 times larger than the delivery ratio for a control mouse on Day 4. This suggests that stem cells were homing to the damaged myocardium.