MSCs and hyaluronan: sticking together for new therapeutic potential?

Research involving mesenchymal multipotent/stem/progenitor/stromal/marrow cells (MSCs) have translated to clinical trials at an extraordinary pace. By the time of this review, the public clinical trials database (http://clinicaltrials.gov) has 394 clinical trials listed using MSCs for a very wide range of therapeutic applications. Unexpectedly, the explanation for the increase in clinical trials using MSCs does not lie on a well-defined therapeutic mechanism--dramatic results have been demonstrated in a variety of studies involving different animal models of diseases, often describing discrete therapeutic mechanisms exerted by MSCs. This review will focus on recent data suggesting the involvement of hyaluronic acid (HA) in the beneficial effects of MSCs, evaluate the potential of MSC as modulators of HA and the implications of this modulation for disease therapy.