Mesenchymal stem cells and their extracellular vesicles: a new therapeutic landscape in bronchopulmonary dysplasia

INTRODUCTION: Bronchopulmonary dysplasia (BPD) remains a major complication of preterm birth, with increasing incidence despite advances in neonatal care. Mesenchymal stromal cells (MSCs) and their extracellular vesicles (EVs) have emerged as potential therapeutic strategies targeting key pathogenic mechanisms of the disease. METHODS: This narrative review critically summarises preclinical and clinical evidence on MSC- and EV-based therapies for BPD, focusing on therapeutic effects, mechanisms of action and translational challenges. RESULTS: Preclinical studies consistently show that MSC-EVs improve lung structure and function, promoting alveolarisation and angiogenesis while reducing inflammation, fibrosis, oxidative stress and apoptosis. These effects translate into improved pulmonary outcomes in animal models. Early-phase clinical studies of MSCs demonstrate safety and feasibility but provide limited and inconsistent evidence of efficacy. Clinical data on EV-based therapies remain scarce, with ongoing trials. Significant heterogeneity in study design, EV characterisation, dosing and administration routes limits comparability and clinical translation. DISCUSSION: MSCs and their EVs represent promising therapeutic approaches for BPD; however, their clinical implementation is hindered by limited efficacy data and a lack of standardisation. Addressing these challenges through rigorous trial design, standardised manufacturing and characterisation and mechanistic understanding will be essential to advance EV-based therapies towards clinical application.