Desirable Human Cell Engraftment Highly Benefit From Efficient Intra-bone Marrow Injection Of Human Umbilical Cord Blood-derived Hematopoietic Stem/progenitor Cells In Xenotransplanted NOD/SCID Mouse Model

Umbilical cord blood (UCB) has been proved to be an alternative source of hematopoietic stem/progenitor cells (HS/PCs) for patients without matched sibling donors due to their main practical advantages of relatively ease of procurement and available for immediate use. Clinical experience provides further evidence to increase awareness of hematologists worldwide to use UCB transplantation (UCBT) to treat patients with hematological malignancies, more than 4,000 UCBTs have been performed worldwide to date. But compared with bone marrow transplantation (BMT) and mobilized peripheral blood stem cell transplantation (mPBSCT) recipients, UCBT recipients have the severely delayed neutrophil and platelet recoveries due to their slow engraftment leading to high risks of infectious and bleeding complications together with a documented 10 to 15 percent graft failure rate increased dramatically post-UCBT transplantation-related mortality (TRM). Recently, the importance of low graft CD34 cell dose has been clarified in determining poor outcome after unrelated donor UCBTs. Introducing limited number of hematopoietic stem/progenitor cells (HS/PCs) from UCB directly into bone marrow microenvironment by efficient use of intra-bone marrow injection (iBMI) strategy might produce desirable human cell engraftment in xenotransplanted NOD/SCID mouse model. Superior8-week-engraftment was observed in injected bone (R-tibia) as well as non-injected bones (including R-femur, L-tibia and L-femur), spleen and peripheral blood in iBMI-UCBT recipients. More superior 8-week-engraftment was observed in...