Breakthrough bone marrow model could reduce need for animal testing

RESEARCHERS have replicated the body’s blood-producing system by creating a bone marrow model made entirely from reprogrammed human cells.

A team at the University of Basel and University Hospital Basel in Switzerland has developed an artificial bone marrow model containing blood vessels, bone cells, nerves and immune cells, which it says can sustain human blood formation in the laboratory for weeks.

The innovation could open up new and more sustainable methods for blood cancer research and drug therapies. Bone marrow typically relies on animal testing and lab experiments with “oversimplified” cell cultures.

Ivan Martin, one of the leaders of the research, said: “Our model brings us closer to the biology of the human organism. It could serve as a complement to many animal experiments in the study of blood formation in both healthy and diseased conditions.”

Building blood

Bone marrow contains several microenvironments, or niches, including one at the bone surface that plays a key role in blood formation and resistance to blood cancers.

This niche, known as the endosteal niche, is the focus of the team’s model, as no existing bone marrow model has successfully incorporated the blood-forming components found in this microenvironment.

To create a robust model, the team constructed an artificial bone structure made from hydroxyapatite, a natural component of bone.

The bone marrow cells were derived from reprogrammed pluripotent stem cells – “master cells” that can be developed into specialised cell types. The researchers guided these cells through the artificial bone structure, enabling them to mature into a wide range of bone marrow cell types.

Small steps

The research team is particularly interested in how their findings could help reduce reliance on animal testing in studies of blood-related diseases.

Looking ahead, they hope the system can be miniaturised so it can be used for drug development. However, co-lead researcher Andrés García García noted: “The size of our bone marrow model might be too large.”