Mesenchymal stem cell stroke therapy: current limitations in its clinical translation

For more than a decade now, research studies, proof of concept work, and clinical trials have endeavored to understand how mesenchymal stem cells might be used to help protect, repair, and/or regenerate damaged brain tissue following stroke. To date, the majority of studies have not demonstrated significant improvements in either morbidity or medium-long-term outcome, although safety has been relatively well proven. Limitations are likely to be linked to the pathobiological complexity and seriousness of stroke tissue damage, low efficacy of treatment, and short half-life of bio-active proteins released by stem cells. This article will highlight the heterogeneity and limitation of completed studies and the current status of ongoing work. At the same time, the potential of other combinational type treatments, such as drug-loading and targeting, and the use of hydrogels is discussed.