A New Way To Create Human Blood in The Lab
- Lidi Garcia
- Oct 16
- 4 min read
Scientists at the University of Cambridge have successfully created structures in the laboratory that mimic human embryos and produce blood naturally. These structures, called "hematoids," self-organize from stem cells and generate both blood and heart cells. The discovery helps understand how blood forms early in life and could lead to the creation of blood compatible with each patient, benefiting the treatment of diseases such as leukemia and opening up new possibilities in regenerative medicine.
Researchers at the University of Cambridge have discovered a unique way to produce human blood cells in the laboratory, closely recreating the natural process that occurs within human embryos.
This achievement marks an important advance in biomedicine, as it allows the study of how blood forms in the early stages of life and may, in the future, help treat diseases such as leukemia, as well as enable the creation of blood stem cells for transplants.
The experiment began with human stem cells, special cells capable of transforming into any type of cell in the body. The team stimulated these cells to self-organize into three-dimensional structures resembling developing human embryos. These structures were called "hematoids." They began to form layers and tissues on their own, much like what happens naturally during the first weeks of pregnancy.
On the second day of observation, the hematoids began to organize themselves into three basic layers called ectoderm, mesoderm, and endoderm. These layers are like the foundation of the human body: from them arise all organs and tissues, including the nervous system, the heart, and the blood.
On the eighth day, scientists observed pulsating heart cells, an indication that the system was functioning in a coordinated manner. Finally, on the thirteenth day, small red spots began to appear on the structures; these were the first naturally formed blood cells, visible even to the naked eye.
These blood cells develop at a stage that corresponds approximately to the fourth or fifth week of a real human embryo. It is a stage of development that cannot be studied directly in humans because at this stage the embryo is already implanted in the mother's uterus. Therefore, models like hematoids are extremely valuable: they allow us to observe and understand biological phenomena that were previously invisible to science.
Stem cell-derived embryo models called hematoids at 14 days of development.
Hematoids, while mimicking many aspects of human development, are not true embryos. They lack essential structures such as the yolk sac, placenta, or other tissues that support the growth of a real embryo. Therefore, there is no possibility of them developing into a complete human being. This makes them a safe and ethical tool for biomedical research.
One of the most innovative aspects of this discovery is that, unlike other existing methods, scientists did not need to add external proteins or substances to guide the cells' development.
The hematoids' own internal environment created the ideal conditions for the stem cells to transform into blood and even beating heart cells within the same system. This represents a major change: instead of forcing the cells to behave in a specific way, the researchers simply recreated the natural environment in which they "know" what to do.
The stem cells used in the study can be obtained from any cell in the human body. This means that, in the future, it will be possible to produce blood that is fully compatible with a patient's body, a fundamental advancement for personalized medicine. This technology could reduce the risk of transplant rejection and offer safer, more durable alternatives for patients with serious hematologic diseases.
The study also paves the way for new ways to simulate blood diseases, such as leukemia, in the laboratory. This will allow scientists to test drugs and better understand how abnormal cells arise and multiply. Furthermore, since immune system cells also originate from blood stem cells, hematoids could help understand the development of the human body's defenses.
The results were published in the scientific journal Cell Reports, and the work received approval from ethics committees, following the strict guidelines governing the study of human embryo models. The research group also filed a patent through Cambridge Enterprise, the University of Cambridge's innovation arm, to ensure that this technology can be safely developed and applied in medicine in the future.
According to Professor Azim Surani, one of the study's leaders, the discovery represents "a significant step toward future regenerative therapies," treatments that use a patient's own cells to repair damaged tissue.
Researcher Jitesh Neupane, who led the experiments in the laboratory, described the moment he saw the red blood appear on the plates as "exciting and unforgettable." Scientist Geraldine Jowett, also a member of the team, emphasized that hematoids allow us to observe a "second wave" of blood formation, which gives rise to specialized immune system cells, such as T cells, which are essential for fighting infections and even cancer.
Thus, this discovery not only helps us understand how human blood forms in the first days of life, but also ushers in a new era in biomedical research, bringing science closer to a future in which we can create blood tailored to each individual.
READ MORE:
A post-implantation model of human embryo development includes a definitive hematopoietic niche
Neupane, J. et al
Cell Reports, October 2025.
DOI: 10.1016/j.celrep.2025.116373
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