Dual-modal magnetic resonance and photoacoustic tracking and outcome of transplanted tendon stem cells in the rat rotator cuff injury model.

Stem cells have been used to promote the repair of rotator cuff injury, but their fate after transplantation is not clear. Therefore, contrast agents with good biocompatibility for labeling cell and a reliable technique to track cell are necessary. Here, we developed a micron-sized PLGA/IO MPs to label tendon stem cells (TSCs) and demonstrated that PLGA/IO MPs were safe and efficient for long-term tracking of TSCs by using dual-modal MR and Photoacoustic (PA) imaging both in vitro and in rat rotator cuff injury. Moreover, TSCs improved the repair of injury and the therapeutic effect was not affected by PLGA/IO MPs labeling. We concluded that PLGA/IO particle was a promising dual-modal MR/PA contrast for noninvasive long-term stem cell tracking.