Ludy Dobrila

Isolation and characterization of mesenchymal stem cells from human umbilical cord blood: Reevaluation of critical factors for successful isolation and high ability to proliferate and differentiate to chondrocytes as compared to mesenchymal stem cells from bone marrow and adipose tissue

Human umbilical cord blood (CB) is a potential source for mesenchymal stem cells (MSC) capable of forming specific tissues, for example, bone, cartilage, or muscle. However, difficulty isolating MSC from CB (CB‐MSC) has impeded their clinical application. Using more than 450 CB units donated to two public CB banks, we found that successful cell recovery fits a hyper‐exponential function of time since birth with very high fidelity. Additionally, significant improvement in the isolation of CB‐MSC was achieved by selecting cord blood units having a volume ≥90 ml and time ≤2 h after donors birth. This resulted in 90% success in isolation of CB‐MSC by density gradient purification and without a requirement for immunoaffinity methods as previously reported. Using MSC isolated from bone marrow (BM‐MSC) and adipose tissue (AT‐MSC) as reference controls, we observed that CB‐MSC exhibited a higher proliferation rate and expanded to the order of the 1 × 109 cells required for cell therapies. CB‐MSC showed karyotype stability after prolonged expansion. Functionally, CB‐MSC could be more readily induced to differentiate into chondrocytes than could BM‐MSC and AT‐MSC. CB‐MSC showed immunosuppressive activity equal to that of BM‐MSC and AT‐MSC. Collectively, our data indicate that viable CB‐MSC could be obtained consistently and that CB should be reconsidered as a practical source of MSC for cell therapy and regenerative medicine using the well established CB banking system. J. Cell. Biochem. 112: 1206–1218, 2011.

Impact of delayed umbilical cord clamping on public cord blood donations: can we help future patients and benefit infant donors?

Cord blood (CB) is a widely accepted stem cell source and its clinical utilization depends, to a great extent, on its cell content. Birth‐to‐clamping (BTC) time of umbilical cord determines placental transfusion to the newborn, and the remaining blood that can be collected and banked. The 2017 Committee Opinion of the American College of Obstetrics and Gynecologists (ACOG) recommends a delay of “at least 30‐60 seconds” before clamping the cord for all newborns to ensure adequate iron stores. The impact of delayed cord clamping (DCC) on public CB banking can be substantial.

Cord Blood Processing: Different Bags and Automation

Cord blood (CB) banking is a worldwide resource that primarily supports hematopoietic progenitor cell (HPC) transplantation. Increasingly, CB is used as a source of HPCs, other neonatal cell types, and proteins for biomedical research and new therapies, such as ophthalmological tissue regeneration and platelet lysates for tissue culture. This chapter will review the methods used to prepare a volume-reduced HPC-enriched fraction from the blood collected at birth, from the placenta and umbilical cord of neonates, as well as the methods for its cryopreservation and storage under cryogenic conditions. Initially, a manual procedure allowed the centrifugal separation of a buffy-coat fraction that was cryopreserved with dimethyl sulfoxide (DMSO) and frozen under controlled rate, with aliquots of the product being separated into unattached freezing vials, for use as future test samples. Subsequently, automated methods for withdrawing the buffy coat have been introduced that allow for aliquots of the cord blood unit (CBU) to be segregated into sealed “segments” of its integral plastic tubing, enabling monitoring the identity, viability, and potency of the CBU, including testing at the time of use. The stability of the CBUs and their segments after many years of storage has been established, as well as their safety and effectiveness. Food and Drug Administration (FDA) has determined that the CBUs produced according to established norms are safe and effective and has issued licenses to CBUs produced by a growing number of cord blood banks (CBBs). CBUs that do not meet the required thresholds for use in HPC transplantation are currently either used clinically if met with other criteria or for research in the generation of tissues and cells for regenerative medicine and immunotherapy. However, challenges, including costs and declining CBU utilization, may interfere with the expanding potential for CB clinical and research applications.

Cytomegalovirus viral load in cord blood and impact of congenital infection on markers of hematopoietic progenitor cell potency

The low incidence of cytomegalovirus (CMV) infection in neonates decreases the risk of viral transmission with cord blood transplantation. Cord blood donors are screened by testing the maternal sample for total antibodies to CMV. Some cord blood banks also screen cord blood for CMV‐DNA. The aim of this study was to develop and validate a multiplex real‐time polymerase chain reaction assay to measure CMV viral load in cord blood from asymptomatic infants with congenital CMV infection and to assess the impact of CMV infection on cord blood hematopoietic progenitor cell concentrations and colony‐forming unit functionality.