Optimal tissue sources of mesenchymal stromal cells for clinical applications

Mesenchymal stromal cells (MSCs) are multipotent cells that can differentiate into the mesenchymal lineages of fat, bone, and cartilage. They are of particular interest because they can preferentially migrate to sites of inflammation and injury and can be transplanted into patients without the need for immune suppression. These remarkable qualities have allowed MSCs to be used for a range of differing medical conditions within the clinic and they are proving to be a promising candidate for an allogeneic "off-the-shelf' cellular therapy ready for immediate use in acute or chronic medical settings. Although these cells were traditionally derived from the bone marrow, investigators have found that MSCs can be derived from alternative sources that are younger, more easily accessible and usually regarded as "biological waste material." While MSC-like populations have been isolated from almost every tissue in the body, it has been found that MSC populations retain a "memory of tissue origin" resulting in different functional abilities. This suggests that differences in MSC populations may be important for the development of future MSC therapeutic approaches for tissue and organ repair and that careful consideration is required when choosing a source of MSCs for clinical trials