Mesenchymal stromal cell therapy to promote cardiac tissue regeneration and repair.

PURPOSE OF REVIEW: This review focuses on articles published from January 2015 to June 2016 on mesenchymal stromal cell (MSC) therapy for cardiac regeneration and repair.

RECENT FINDINGS: During this period, reports published on MSCs address the best MSC tissue source for cellular therapy, mechanisms of MSC activity and improving MSC longevity, and homing in vivo. Currently, there is no definitive therapeutic advantage of any one tissue-derived MSC over another, and even combination therapies struggle with conflicting outcomes. MSC activity, persistence in vivo, or homing can be improved by priming strategies, genetic modification, or biomaterials. Despite numerous studies showing improvement in heart function after acute cardiac injury, the reproducibility and efficacy of the therapy remains elusive and falls short of expectations in clinical trials. Although the safety of MSCs is undisputed, the success of MSC preparations in improving cardiac function clinically remains uncertain due to challenges in correlating MSC potency with clinical outcomes, donor-related variation in MSC function, and a profusion of culture methodologies.

SUMMARY: Several strategies are available to advance MSC cell therapy for acute cardiac injury to promote cardiac regeneration and repair in rigorous preclinical and clinical studies.