Blood collected from the umbilical cord and placenta after birth has long helped rebuild patients' blood and immune systems through stem cell transplantation. Its possibilities may extend much further.
Recently, the team led by Tao Cheng, Linping Hu and Sha Hao from the Hematology Hospital of the Chinese Academy of Medical Sciences (Institute of Hematology, Chinese Academy of Medical Sciences) has published a review titled “Current Understanding and New Promises of Umbilical Cord Blood in Emerging Clinical Applications” in the journal Science China Life Sciences （IF=9.6）. This review charts how umbilical cord blood could become a broader platform for cell therapy, bringing together its stem cells, immune cells and bioactive components.
Umbilical cord blood's established role rests on hematopoietic stem cells, which can generate the different blood cell lineages. Transplantation has been used for blood cancers and selected inherited blood, immune and metabolic disorders. Banked cord blood can offer an alternative when a suitable donor is unavailable, although the limited number of cells in a single unit can delay recovery after transplantation.
The review looks beyond this familiar use to the diversity of cord blood's components. These include T cells and natural killer cells, which can attack abnormal cells; regulatory T cells, which help control immune responses; and progenitor cells involved in vascular repair. Their distinct biological properties make cord blood a source for several therapeutic strategies, rather than a single type of treatment.
Cancer immunotherapy is a major focus. Researchers are exploring ways to expand and engineer cord blood-derived immune cells, including adding chimeric antigen receptors that help cells recognize tumor targets. The review also describes generating engineered natural killer T cells from cord blood stem and progenitor cells. Such approaches could support donor-derived, off-the-shelf therapies prepared in advance, but experimental tumor control does not by itself establish clinical benefit.
Other immune-cell approaches aim to tune immune responses rather than simply intensify them. Cord blood-derived regulatory T cells are being studied to reduce harmful inflammation and graft-versus-host disease, a complication in which donor immune cells attack the recipient's tissues. Dendritic cells, which present antigens to other immune cells, offer another route under investigation for cancer vaccines and combination immunotherapies.
In regenerative medicine, the review examines mesenchymal stromal cells, endothelial progenitor cells and mixed populations of mononuclear cells. Research has explored these populations for cartilage repair, vascular injury and neurological damage, among other conditions. Their effects may involve releasing molecules that regulate inflammation, support cell survival or promote blood vessel formation, rather than simply replacing damaged tissue. The evidence spans laboratory studies, animal models and clinical investigations, with different levels of maturity.
Cell source is an important distinction. Mesenchymal stromal cells obtained from cord blood are not interchangeable with those obtained from umbilical cord tissue. Cord tissue can provide a more readily isolated and expandable source for some manufacturing applications, so findings from one source should not automatically be attributed to the other.
The possibilities are not limited to transplanted cells. Cord blood plasma and platelet-rich products contain growth factors and other bioactive molecules being investigated for tissue repair and cell culture. The review also discusses small vesicles released by cord blood-derived cells that carry signaling molecules. These directions broaden the range of potential products, while creating their own challenges in preparation, delivery and consistency.
Technology is helping researchers address the gap between a promising biological resource and a usable treatment. The review brings together advances in growing cells outside the body, gene modification and engineered culture environments that mimic aspects of the stem cell niche. These methods aim to increase cell numbers while preserving useful functions, or to generate specialized immune cells. Improved cryopreservation and post-thaw recovery are also important for banked products.
Significant barriers remain. Donor variability, limited cell dose and the functional immaturity of some immune cells can complicate product development. Large-scale manufacturing must deliver consistent cell expansion and engineering. For regenerative and noncellular approaches, delivery methods and sustained effects also need optimization. The authors emphasize the need to establish durable clinical benefit and refine collection, storage and regulatory practices as applications expand.
Umbilical cord blood banks could serve not only transplantation, but a wider range of cell-based and regenerative technologies. Realizing that vision will depend on matching each product to its intended use and evidence base. The potential is substantial, but turning it into reliable treatments requires continued biological, manufacturing and clinical progress.
Science China Life Sciences
Literature review