In vivo stem cell tracking in neurodegenerative therapies

Introduction: Cell transplants to replace cells lost due to injury or degenerative diseases, for which there are currently no cures, are being pursued in a wide range of experimental models. Thus, the application of stem cell-based therapies to treat neurodegenerative and traumatic injuries is now a clinical reality. However, the monitoring of cellular grafts, non-invasively, is an important aspect of the ongoing efficacy and safety assessment of cell-based therapies. Hence, there is a need for non-invasive imaging techniques to ensure that transplants are not only administered to the relevant site, but also allow the monitoring of inappropriate cellular migration to improve our understanding of stem cell migration in the context of the whole organism. Areas covered: This review provides an up to date overview of molecular imaging approaches that have been used for visualizing and tracking transplanted stem cells, in vivo. Expert opinion: It's important to emphasize that the application of molecular imaging to interrogate transplanted cells may require one or even two imaging modalities to provide a reasonable assessment of transplanted cells in specific organs.