EPCs in vascular repair: how can we clear the hurdles between bench and bedside?

Endothelial progenitor cells (EPCs) play a fundamental role in the maintenance and repair of damaged vascular endothelium, as well as in new blood vessel formation. Based on this function of EPCs, it has been hypothesized that transfusion of these cells could be an approach to treat vascular disease. While this concept has subsequently been proven in animal models clinical trials have not been encouraging. These discrepancies have limited translation of EPCs from bench to bedside. In this review, by analyzing the reported data from the animal models and clinical trials, we describe the main factors limiting the clinical effects of EPCs infusion and the unfavorable in vivo reactions of the receipts. To facilitate future clinical application of EPCs, a series of strategy to overcome the obstacles have been suggested.