Exosomes in regenerative medicine from biological messengers to engineered nanocarriers for precision therapeutics

Exosomes have emerged as a promising class of next-generation nanocarriers at the intersection of regenerative medicine and drug delivery. Compared with conventional synthetic nanocarriers and stem cell-based therapies, exosomes offer unique advantages, including intrinsic biocompatibility, low immunogenicity, blood-barrier penetration, and natural intercellular cargo transfer. This review critically examines exosome biology, beginning with their biogenesis, structural composition, and roles in cellular homeostasis, immune regulation, autophagy, and tissue repair. Particular emphasis is placed on their therapeutic relevance in wound healing, neuroregeneration, cardiovascular repair, musculoskeletal regeneration, and cancer. The review further discusses major strategies for exosomal cargo engineering, including passive loading, electroporation, sonication, transfection-based approaches, extrusion, freeze–thaw treatment, and chemical functionalization. In addition, scaffold-assisted delivery systems and hybrid exosome–synthetic nanocarrier platforms are highlighted as important advances for improving local retention, targeting precision, and controlled release. Despite strong preclinical promise, translation remains limited by challenges in scalable manufacturing, purification, batch consistency, loading efficiency, potency assessment, and regulatory standardization. Future progress in this field will depend on the development of scalable and GMP-compatible exosome manufacturing, standardized purification and characterization methods, validated potency assays, regulatory-aligned quality control, and artificial intelligence (AI) engineering strategies to translate exosome-based platforms into safe, reproducible, and clinically effective regenerative therapeutics.