Breakthrough in lab-grown blood cells opens new avenues for regenerative medicine
A recent breakthrough from researchers at the University of Cambridge has produced embryo-like structures, called hematoids, that generate human blood cells in the lab. The development offers a powerful new method to study early blood formation and holds promise for regenerative therapies, drug screening, and modelling blood disorders.
What are hematoids and why are they important?
Hematoids are embryo-like structures created from human stem cells that mimic the earliest steps of human development when organs and the blood system begin to form. Unlike real human embryos, these models lack certain tissues, a yolk sac, and a placenta, but they provide a valuable, controllable system to observe the processes that drive blood and immune cell formation in early gestation.
The developmental timeline observed in the lab
Within two weeks in culture, the hematoids began producing blood cells, recapitulating the natural sequence of events seen in human embryogenesis. By day two, the structures organized into three fundamental layers that shape every organ and tissue. By day eight, cells destined to form the heart emerged, and by day 13, red patches resembled the first blood vessels and blood cells. By observing these stages, researchers gain a rare window into stages that are normally invisible in human embryos.
Key findings and potential applications
Co-first author Dr. Geraldine Jowett described hematoids as capturing the second wave of blood development, which can lead to specialized immune cells or adaptive lymphoid cells such as T cells. This could enable multiple important applications:
- Modeling healthy and diseased blood development, including leukaemia, to understand how early blood formation goes awry.
- Drug screening in a system that reflects human embryonic blood development, potentially speeding up the discovery of safer, more effective therapies.
- Creating blood stem cells that could, in the long term, contribute to transplant strategies using a patient’s own cells.
Limitations and what remains to be done
Despite the promise, the researchers emphasise that hematoids do not constitute a complete human embryo. They lack certain tissues and a yolk sac and placenta, which means they cannot progress to full fetal development. The work represents an early-stage model designed to illuminate specific aspects of blood formation rather than replace in vivo studies.
Future directions and impact on medicine
By shedding light on the exact moments when blood and immune cells first form, the hematoid model could help scientists refine regenerative therapies that use a patient’s own cells to repair damaged tissues. In addition, the platform offers a novel way to explore how blood-related cancers develop from the earliest stages, potentially informing prevention strategies and targeted treatments.
About the study and acknowledgement
The research, published in Cell Reports, was conducted by researchers at the University of Cambridge’s Gurdon Institute and funded by Wellcome. The team has also secured a patent through Cambridge Enterprise to protect this innovative approach as it advances toward clinical and drug-development applications.
