Mesenchymal Stem Cell-Derived Exosomes: A Tool for Heart Failure Repair - From Molecular Mechanisms to Clinical Potential.

Exosomes are nanoscale vesicles abundantly distributed across biological fluids, serving as crucial mediators of intercellular communication by carrying bioactive molecules such as proteins, nucleic acids, and lipids. They exert pivotal functions in various physiological and pathological processes. Mesenchymal stem cell-derived exosomes (MSC-exos) exhibit low immunogenicity, minimal tumorigenic risk, abundant sources, and amenability to engineering modifications. Through the targeted delivery of bioactive molecules, MSC-exos exert multifaceted therapeutic effects in heart failure (HF) repair. They not only protect cardiomyocytes, thereby maintaining structural integrity, but also modulate immune and inflammatory responses, thereby improving the myocardial microenvironment. Additionally, they inhibit fibrosis, promote angiogenesis, and optimize myocardial metabolism, offering novel strategies and tools for the treatment of HF. This review aims to systematically elucidate the biological characteristics of MSC-exos, provide an in-depth analysis of their molecular mechanisms in HF therapy, summarize optimization strategies, and explore their potential in drug delivery and clinical applications. Furthermore, it discusses the challenges and future directions for clinical translation, thereby offering a comprehensive reference for both basic research and clinical practice regarding MSC-exos as a therapeutic tool for HF repair.