Umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs) are self-renewing, multipotent, plastic adherent cells, that meet the minimal criteria for defining MSCs recommended by the International Society of Cell Therapy (ISCT). More specifically, they adhere to plastic, can differentiate into adipocytes, chondrocytes and osteocytes and express cell surface antigens CD73, CD90, CD105 but lack the expression of hematopoietic antigens such as CD11b or CD14, CD34, CD45, CD79 or CD19, and HLA-DR.
MSC isolation efficacy from cord blood has been consistently lower than from bone marrow and adipose. UCB-MSC culture under low-oxygen conditions improves the isolation success rate to above 90%, and the UCB- MSCs obtained by this method fulfill the ISCT minimum characterization criteria for MSCs. In addition, MSC colony frequency is lowest when derived from umbilical cord blood when compared to other sources; however, UCB-MSCs can be cultured for longer periods and exhibit a higher proliferative capacity. UCB-MSCs show limited adipogenic differentiation capacity, while bone marrow- and adipose tissue–derived MSCs display a standard tri-lineage differentiation potential.
Umbilical cord blood-derived MSCs possess advantages over their embryonic and adult stem cell counterparts, primarily due to the fact that they sidestep ethical issues associated with isolation of embryonic stem cells. Furthermore, isolation techniques are non-invasive; the cells are less immunogenic and evoke fewer post-transplant infections when compared with other sources.
When considering these factors, UCB-derived MSCs provide an attractive source of therapeutic cells applicable in various diseases.