Orthopedic Surgery

In orthopedic surgery, iliac bone graft which is commonly used for treatment nonunion or spinal fusion is contained multipotential stem cells or mesenchymal progenitor cells. These cells are found approximately 1 in 10,000 nucleated cells in the bone marrow. Friedenstein et al. (1970) reported that a rare population of cells was found by plastic-adherent ability (Friedenstein et al., 1970). These cells are capable of proliferation and mesenchymal lineages differentiation (Pittenger et al., 1999, Caplan, 1991). Unique antigens of MSCs (hMSCs) are controversy and the limited popularity of sorting cells techniques are not as widely used as gradient media in MSC isolation. Most MSC populations have been isolated by plastic adherent ability which is similar to that originally used by Friedenstein. Direct BM plating method is commonly used for cells from small animal (Lennon and Caplan, 2006, Nadri et al., 2007) but in human bone marrow, Density gradient centrifugation is the most commonly used method for isolating MSCs.

So far, it is still controversy to exactly identify of MSC. According to their capability of proliferation and multilineage differentiation, Colony-forming unit–fibroblast (CFU-F) is defined as highly adherent in colony of fibroblastic-like cells which arising from one mother cell. Thus, CFU-F assay have been used to assess the bone marrow progenitors and The number of colonies formed per a total number of marrow cells seeded or the colony-forming efficiency (CFE), thereby the CFU-F content among marrow cells, representing in vitro enumeration of a clonogenic subset of in vivo marrow stromal cell populations. However, it has been demonstrated that CFU-F populations are not homogeneous but rather contain a hierarchy of progenitors including multipotential mesechymal stem cells and committed progenitors (Friedenstein et al., 1992, Latsinik et al., 1986).

Several surface makers which expressing from mesenchymal stem cells. Basically, these makers are the cell receptors, adhesion molecules, extracellular matrix proteins, cytokines and other molecules that have function as a way of communicating with other cells and to carry out their physiological functions. Thus, these makers are adopted to characterize the homogenous mesenchymal stem cells. However, the Bone marrow-derived stem cells expression of different surface markers which are still controversy. These cells have a negative expression of CD45 which express in Hematopoietic stem cell (HSC) (McKinney-Freeman et al., 2009), CD14 which express in innate immune cells (Cros et al.