Isolation and Characterization of Multipotent and Pluripotent Stem Cells from Human Peripheral Blood

Stem cells are commonly classified based on the developmental stage from which they are isolated, although this has been a source of debate amongst stem cell scientists. A common approach classifies stem cells into three different groupings: Embryonic Stem Cells (ESCs), Umbilical Cord Stem Cells (UCBSCs) and Adult Stem Cells (ASCs), which include stem cells from bone marrow (BM), fat tissue (FT), engineered induced pluripotent (IP) and peripheral blood (PB). By definition stem cells are progenitor cells capable of self-renewal and differentiation hypothetically “ab infinitum” into more specialized cells and tissue. The main intent of this study was to determine and characterize the different sub-groups of stem cells present within the human PB-SCs that may represent a valid opportunity in the field of clinical regenerative medicine. Stem cells in the isolated mononucleated cells were characterized using a multidisciplinary approach that was based on morphology, the expression of stem cell markers by flowcytometry and fluorescence analysis, RT-PCR and the capacity to self-renew or proliferate and differentiate into specialized cells. This approach was used to identify the expression of hematopoietic, mesenchymal, embryonic and neural stem cell markers. Both isolated adherent and suspension mononucleated cells were able to maintain their stem cell properties during in-vitro culture by holding their capacity for proliferation and differentiation into osteoblast cells, respectively, when exposed to the appropriate induction medium.