Abstract

 Background and Objectives

 Umbilical cord blood (UCB) is an accessible source of hematopoietic stem cells (HSCs). Along with the advantages, UCB also has limitations: the low volume and the absolute number of HSCs available in UCB leading to the delayed engraftment. Given the limitations, many investigators have sought to accelerate engraftment and increase the absolute number of stem cells in UCB units.

 Materials and Methods

 In the present study more than 200 published articles about UCB were reviewed. This review article is aimed to focus on the importance of using cord blood, the nature of stem cells in cord blood, and the ex vivo expansion techniques of UCB HSC.

 Results

 UCB HSCs possess higher proliferative potentials and contain a higher proportion of primitive compartment as compared to bone marrow and peripheral blood. Several studies have reported the presence of different cell populations besides HSCs in cord blood that enable the use of these sources in immunotherapy, tissue engineering, and regenerative medicine. Thus, the strategies to isolate and expand selected subpopulations from UCB and the use of these cells in treatment of various diseases are the areas of active research.

 Conclusions

 Umbilical cord blood is an attractive source in both research and modern clinical applications providinh a potentially useful alternative for patients who do not have an HLA-matched bone marrow donor. Besides the safety and feasibility of UCB, the other areas including the acceleration of the engraftment, the extension of access, the quality assurance, and the outcomes in the specific subgroups of patients are also required to be investigated.