Mesenchymal stem/stromal cells: a new ''cells as drugs'' paradigm. Efficacy and critical aspects in cell therapy

Abstract

Mesenchymal stem cells (MSCs) were first isolated more than 50 years ago from the bone marrow. Currently MSCs may also be isolated from several alternative sources and they have been used in more than a hundred clinical trials worldwide to treat a wide variety of diseases. The MSCs mechanism of action is undefined and currently under investigation. For in vivo purposes MSCs must be produced in compliance with good manufacturing practices and this has stimulated research on MSCs characterization and safety. The objective of this review is to describe recent developments regarding MSCs properties, physiological effects, delivery, clinical applications and possible side effects.

Fig. (1)

Schematic representation of the most common strategies for the MSCs administration in clinical settings. Bioptic tissues from donors (allogeneic use) or from the patient (autologous use) are used to isolate MSCs. The cell suspension can be administrated by intravenous or intra-arterial infusion (blue ring), or vehiculated on injectable products, as hydrogels or microcapsules, and injected into the target tissue (orange ring), or loaded on solid implantable scaffolds and transplanted during surgery (purple ring). (The color version of the figure is available in the electronic copy of the article).