Sarcopenia's regenerative failure stems from a dual collapse: resident satellite cells (SCs) become exhausted and dysfunctional while their surrounding niche degenerates through cellular senescence, chronic low-grade inflammation, and fibro-adipogenic conversion of stromal tissue. This review maps how each major cell therapy candidate—SCs, mesenchymal stromal cells, pericytes/mesoangioblasts, and hematopoietic stem cells—deteriorates with age, and evaluates pluripotent stem cell (PSC) differentiation and direct reprogramming as autologous strategies that sidestep donor-age limitations.
Sarcopenia affects roughly 10–16% of adults over 60 and accelerates frailty, metabolic dysfunction, and mortality risk—yet no disease-modifying therapy exists. The field has long recognized that transplanting aged cells into aged microenvironments produces disappointing engraftment, a chicken-and-egg problem this review addresses head-on. The niche-conditioning angle is particularly timely: senolytics, anti-inflammatory preconditioning, and extracellular matrix remodeling are emerging as prerequisite steps before any cellular graft can take hold. The PSC reprogramming strategy is compelling because it could theoretically restore youthful epigenetic states to a patient's own cells, sidestepping immune rejection and donor variability simultaneously—though manufacturing scalability, teratoma risk, and regulatory hurdles remain formidable. As a comprehensive review rather than primary data, this work synthesizes rather than generates evidence, so its value lies in framing rather than causation. Still, its critical triangulation of preclinical gaps and clinical translation barriers makes it an unusually useful roadmap for researchers and clinicians pursuing regenerative medicine for aging muscle.