Adipose-Derived Mesenchymal Stem Cells: Isolation, Origin, Phenotype Applications, and Challenges.

Traditional adipose-derived mesenchymal stem cells (AD-MSCs) research has relied on unfractionated bulk populations, whose therapeutic efficacy is constrained by cellular heterogeneity, culture-induced phenotypic drift, and rapid postengraftment functional exhaustion, resulting in inconsistent outcomes and impeding clinical translation. This review systematically examines AD-MSC developmental origins, tissue niches, isolation and purification strategies, functional phenotypes, and biomanufacturing bottlenecks. It integrates preclinical and clinical evidence for AD-MSCs and their extracellular vesicles (EVs) in bone and cartilage regeneration, chronic cutaneous diseases, neurological disorders, cardiovascular diseases, and other conditions. These therapies remodel injured microenvironments through immunometabolic reprogramming, antifibrotic signaling, angiogenesis, mitochondrial transfer, and paracrine regulation rather than direct tissue replacement. Major translational barriers include cellular heterogeneity, safety concerns, the transdifferentiation controversy, nonstandardized preconditioning, culture-induced phenotypic drift, and low cell retention after transplantation. We propose that clinical translation should be based on prospective isolation of functional subpopulations, coupled with tailored preconditioning, precision gene editing, three-dimensional biomaterials, EV engineering, and automated closed-system biomanufacturing. This framework aims to preserve potency, phenotypic stability, and paracrine function, transforming AD-MSCs and their bioactive derivatives from variable, unfractionated preparations into well-characterized, standardized, highly potent precision biologics. More broadly, it offers a mechanism-driven, function-defined, engineering-enabled, and clinically accessible roadmap for next-generation regenerative medicine.