Regenerative medicine which includes tissue engineering, gene therapies and cell-based therapies has expanded rapidly over the last decade and has a great potential to treat and cure human diseases. Specifically, cell-based therapies are developing as an efficacious alternative therapeutic option.
Cell-based therapy involves different types of cells such as immune cells and various stem cells. Stem cells are special body cells that can differentiate into various types of cells to produce different cell types: from muscle cells to brain cells. Under some circumstances, stem cells can fix damaged tissues. Different stem cells types can be obtained from the human tissues, such as Embryonic stem cells, amniotic fluid stem cells, Non-embryonic (adult or somatic) stem cells (such as Bone Marrow mesenchymal stem cells or adipose tissue-derived mesenchymal stem cells), induced pluripotent stem cells (iPSCs) and Umbilical Cord blood stem cells,, among others. Stem cells have two main properties: self-renewal and potency. The ability to self-renew means that a given stem cell can divide itself in the exact same copy and keep existing. The potency of a stem cell is its ability to specialize (differentiate) into various types of cells. Some stem cells can specialize themselves into one type of cells (unipotent), others in various types of cells (multipotent), and a few can become any cell of the human body (pluripotent).
Mesenchymal stem cells (MSCs) are the spindle shaped plastic-adherent cells isolated from bone marrow, adipose, and other tissue sources such as umbilical cord and the placenta with multipotent differentiation capacity in vitro. Although MSCs are multipotent and have the ability to differentiate to different cell types, especially those of the mesodermal lineage, their mechanism of action is based on endocrine/paracrine activity involving the secretion of active peptide like cytokines and growth factors that stimulate tissue repair and modulate the body’s immune response.
Thus, whether MSCs truly qualify as stem cells is an area of some debate . Extra embryonic tissues previously seen as medical waste are increasingly recognized as a prized source of MSCs for therapeutic use.
When compared with MSCs produced from adult tissues, MSCs of neonatal origins exhibit improved proliferation ability, lower immunogenicity, and possible lower mutation tendency. More specifically, in the past two decades, the human placenta has become a consolidated source of MSCs that possess unique properties.
MSCs appears as a more appropriate cell product for therapeutic purposes  due to their high availability, the ability to rapidly expend in vitro, excellent safety profile as well as their lower ethical challenges, low risk of tumorigenicity and low immunogenicity enabling transplantation with Human Leukocyte Antigens matching.
- Horwitz EM, Keating A. Nonhematopoietic mesenchymal stem cells: what are they? Cytotherapy. 2000;2:387–388.
- Parekkadan B, Milwid JM. Mesenchymal stem cells as therapeutics. Annu Rev Biomed Eng. 2010;12:87-117.