Hurdles to overcome for mesenchymal stem cell translation from bench to bedside

Mesenchymal stem or stromal cells (MSCs) are among the most extensively studied cell populations in regenerative medicine due to their multipotent differentiation potential, secretion of trophic factors, and immunomodulatory effects. Over the past two decades, preclinical studies have demonstrated encouraging results across musculoskeletal, cardiovascular, neurological, and immune-mediated disorders. However, the translation of MSCs from the laboratory to routine clinical practice remains hindered by unresolved scientific, technical, and regulatory challenges. This review provides a critical appraisal of these hurdles, organized across three major stages of translation: <i>In vitro</i> research, <i>in vivo</i> animal studies, and clinical application. <i>In vitro</i> issues include the heterogeneity of isolation techniques, replicative senescence during expansion, genetic and epigenetic instability, and the need for xeno-free, standardized culture platforms. <i>In vivo</i> challenges arise from poor cell survival, low engraftment rates, off-target migration, and microenvironmental influences that shape therapeutic outcomes. Clinical translation introduces additional complexity, including inter-patient variability, large-scale manufacturing difficulties, stringent regulatory compliance, high production costs, and the absence of harmonized potency assays. Solutions under exploration include the use of automated bioreactors, biomimetic scaffolds, hypoxic preconditioning, extracellular vesicle-based therapies, and international standardization efforts. Addressing these hurdles through multidisciplinary collaboration is essential for MSC-based therapies to become reliable, safe, and accessible regenerative treatments.