According to the latest issue of Nature Biotechnology magazine, a research team led by Murdoch Children's Research Institute in Australia has for the first time produced hematopoietic stem cells in a laboratory that closely resemble human tissue. This achievement may bring personalized treatment plans for leukemia and bone marrow failure patients. Previously, the development of human blood stem cells that could be transplanted into animal models and produce healthy blood cells in the laboratory has been impossible. Now, researchers have developed a workflow to create transplantable blood stem cells that are very similar to those found in human embryos. Importantly, these stem cells can be cultured at the scale and purity required for clinical use. Human blood or skin cells are converted into pluripotent stem cells through "reprogramming". During this process, four genes are temporarily activated, and these cells return to the early stages of development and can transform into any cell in the body. Researchers transformed these pluripotent cells into blood stem cells. They created thousands of cell spheres suspended in liquid culture medium, each sphere containing hundreds of cells. In about two weeks, stem cells can differentiate into vascular cells, producing millions of blood cells. The researchers then injected these blood cells into immunodeficient mice. 50% of the blood cells became functional bone marrow. This means that they produce the same oxygen carrying and infection resistant cells as those in healthy human bone marrow. This unique ability to produce all types of blood cells over a long period of time has prompted researchers to define these cells as blood stem cells. The study also found that laboratory cultured stem cells can be cryopreserved before successful transplantation into mice, simulating the preservation process of donor blood stem cells before transplantation to patients. Hematopoietic stem cells can often give blood disease patients a "second life", however, not all patients can be successfully matched. The new process means that researchers can use any cell on the patient's body to reprogram it into stem cells and then convert them into specific blood cells for transplantation, which will have a huge impact on the patient's life and health. Researchers say that this study marks a significant breakthrough in the development of new therapies for hematological cancer. But before applying this method to clinical practice, extensive testing is still needed on humans. (New Society)