Cardiac Repair and Mesenchymal Stem Cells: Exploring New Frontiers in Regenerative Medicine.

Cardiovascular diseases, especially myocardial infarction, remain the prominent causes of death globally, necessitating the exploration of innovative therapeutic strategies. Medical and surgical available treatments mainly manage disease symptoms and prevent deterioration, but do not focus on the repair of lost cardiomyocytes. Mesenchymal stem cells (MSCs) have emerged as a promising tool for heart repair and regeneration after injury, as they possess unique properties, such as the potential for differentiation into cardiomyocytes and vascular endothelial cells, immunomodulation, the release of mediators, and paracrine effects. This review focuses on the latest understanding of MSC therapies for cardiac repair, specifically addressing their properties, mechanism of action, preclinical and clinical studies, problems and prospects, and future strategies. MSCs can be isolated from various tissues, including bone marrow and adipose tissue, each with its own advantages and disadvantages in cardiac repair. Many preclinical studies conducted concluded that MSCs could differentiate into cardiomyocytes. MSCs involve multiple factors that enhance angiogenesis, promote the survival of existing myocardium and cardiomyocytes, reduce fibrosis, modulate the immune response, activate existing cardiac stem cells, and facilitate tissue remodeling; all of these processes are crucial in myocardial repair after MI. Although preclinical studies have promising outcomes, the application of MSC therapy in clinical trials has faced many challenges. Clinical trials conducted so far have yielded variable outcomes, with some showing marked improvements and others producing no promising results, indicating less improvement in cardiac function and mortality. This variability may be due to multiple sources, including MSCs, delivery methods, culture conditions, the timing of administration after MI, and patient-dependent factors, such as disease severity, overall patient well-being, and other comorbid conditions. The review concluded that although MSCs have a significant role in cardiac repair, further research is essential for overcoming current challenges to unlocking the maximum regenerative potential of these cells.