Mesenchymal stem cell priming: fine-tuning adhesion and function

There is significant interest in the use of mesenchymal stem cells (MSCs) as a potential therapeutic modality in disease and disorder, particularly those with an inflammation-based component such as coronary, renal and hepatic diseases. While there is no question that MSCs possess the capability to manipulate an ongoing inflammatory injury, the recruitment of these cells to injured sites is generally poor, and thus, open to manipulation. Enhancing the localised recruitment of MSCs to injured tissues may enhance the efficiency and efficacy of this mode of therapy. A number of techniques exist in the literature to improve the recruitment of MSCs to injured tissues, including the use of cytokines, chemical modifications and coating with either synthetic or biological particles. In addition to enhancing MSC recruitment, there is an increasing body of work examining techniques which may enhance the anti-inflammatory activity of these cells. This review will summarise the literature around these topics. This first section of this review summarises the current literature with regard to MSC homing and their recruitment during conditions of injury. In relation to the anti-inflammatory activity of MSCs, the role of systemic versus local activity will be discussed. The second part of the review focuses on the role of pretreatments in MSC therapy and how these may have potential for not only enhancing the recruitment of MSCs, but also their anti-inflammatory capabilities. In summary, it is clear that there is significant potential to improve the efficiency of MSC therapy and the techniques discussed in this review may be central to this in the future.