Exploring the mesenchymal stem cell niche using high throughput screening.

In the field of stem cell technology, future advancements rely on the effective isolation, scale-up and maintenance of specific stem cell populations and robust procedures for their directed differentiation. The stem cell microenvironment - or niche - encompasses signal inputs from stem cells, supporting cells and from the extracellular matrix. In this context, the contribution of physicochemical surface variables is being increasingly recognised. This paradigm can be exploited to exert control over cellular behaviour. However, the number of parameters at play, and their complex interactions, presents a formidable challenge in delineating how the decisions of cell fate are orchestrated within the niche. Additionally, in the case of mesenchymal stem cells (MSC), more than one type of stem cell niche has been identified. By employing high throughput screening (HTS) strategies, common and specific attributes of each MSC niche can be probed. Here, we explore biological, chemical and physical parameters that are known to influence MSC self-renewal and differentiation. We then review techniques and strategies that allow the HTS of surface properties for conditions that direct stem cell fate, using MSC as a case study. Finally, challenges in recapturing the niche, particularly its three dimensional nature, in surface-based HTS formats are discussed.