QUANTUM DOT LABELED STEM CELLS FOR USE IN CARDIAC REPAIR

摘要

The present invention provides methods and compositions relating to the labeling of target cells with nanometer scale fluorescent semiconductors referred to as quantum dots (QDs). Specifically, a delivery system is disclosed based on the use of negatively charged QDs for delivery of a tracking fluorescent signal into the cytosol of target cells via a passive endocytosis-mediated delivery process. In a specific embodiment of the invention the target cell is a stem cell, preferably a mesenchymal stem cell (MSC). Such labeled MSCs provide a means for tracking the distribution and fate of MSCs that have been administered to a subject to promote cardiac repair. The invention is based on the discovery that MSCs can be tracked in vitro for up to at least 6 weeks. Additionally, QDs delivered in vivo can be tracked for up to at least 8 weeks, thereby permitting for the first time, the complete 3-D reconstruction of the locations of all MSCs following administration into a host.