Mesenchymal stem cells in tissue repair

Abstract

The advent of mesenchymal stem cell (MSC)-based therapies for clinical therapeutics has been an exciting and new innovation for the treatment of a variety of diseases associated with inflammation, tissue damage, and subsequent regeneration and repair. Application-based ability to measure MSC potency and fate of the cells post-MSC therapy are the variables that confound the use of MSCs therapeutics in human diseases. An evaluation of MSC function and applications with attention to detail in the preparation as well as quality control and quality assurance are only as good as the assays that are developed. In vivo measures of efficacy and potency require an appreciation of the overall pathophysiology of the model and standardization of outcome measures. The new concepts of how MSC's participate in the tissue regeneration and wound repair process and further, how this is impacted by estimates of efficacy and potency are important new topics. In this regard, this chapter will review some of the in vitro and in vivo assays for MSC function and activity and their application to the clinical arena.

Keywords: adult mesenchymal stem cells; anti-inflammatory agents; antimicrobial protein; milieu therapy; regenerative pharmacology.

Figure 1

The dynamic definition of MSC efficacy. Efficacy or the biological impact of MSC on biological processes is dependent on a variety of parameter. As outlined in the schematic below the variability in efficacy is dependent not only on the source and quality of the MSCs themselves but also on the response of the recipient to the administration of MSCs. This is a dynamic and continuous process that can ultimately be defined by the potency of the MSCs in the context of disease, model, and outcome measure.

Figure 2

The mesengenic process. Mesenchymal stem cells are multipotent and possess the ability to proliferate and commit to different cell types based on the environmental conditions. They also may be redirected from one lineage to another.