New frontier in regenerative medicine: lab-grown blood cells
Scientists have reported a breakthrough in generating blood cells from human stem cells in the lab, paving the way for regenerative therapies, disease modelling, and improved drug screening. The work centers on creating embryo-like structures, nicknamed hematoids, which recreate the early stages of human development when blood and organs begin to form. While not embryos themselves, these structures offer a powerful window into how blood cells originate and mature.
What are hematoids and how were they made?
Hematoids are embryo-like constructs developed by researchers at the University of Cambridge. Using human stem cells, the team guided the cells to self-organize into layered structures that resemble the early human embryo’s development, including the formation of tissues that will later give rise to the bloodstream. By around two weeks in the lab, the hematoids started producing blood cells, mirroring the natural sequence of human embryogenesis.
Key developmental milestones observed
Within two days, the structures organized into three essential layers that underpin organ and tissue formation. By day eight, precursor cells associated with cardiac development appeared, and by day 13, red patches indicating blood cell formation emerged. The researchers noted that the process simulated a stage of development equivalent to weeks four to five in an actual embryo, a period rarely observable in vivo.
Implications for medicine and research
The team emphasized several potential applications of hematoids and lab-grown blood cells. First, they could enable screening of new drugs for safety and efficacy in a human-like blood environment. Second, the model offers a way to study early blood and immune development, shedding light on how healthy and diseased blood systems form. Finally, the development of blood stem cells in this system could lead to transplant-ready cells for patients, potentially reducing reliance on donor material.
Leukaemia and immune system research
Dr Jitesh Neupane described the model as a “significant step” toward understanding blood formation and disease. The hematoids capture the second wave of blood development that can generate specialised immune cells, including adaptive lymphoid cells like T cells. This makes them a promising platform for modelling both healthy blood formation and disorders such as leukaemia, which could accelerate the discovery of targeted therapies.
Limitations and next steps
Researchers openly acknowledge that hematoids are not living human embryos. They lack certain tissues, a yolk sac, and placenta, and cannot develop into a full fetus. Nevertheless, the model offers a controlled setting to observe blood development and test interventions that could eventually translate to regenerative medicine.
Outlook and funding
The Cambridge team has patented their approach and is continuing to refine the system to broaden its utility in disease modelling and therapy development. The research was published in Cell Reports and funded by Wellcome, marking a collaborative milestone in translating developmental biology insights into clinical potential.
