The hematopoietic stem cell (HSC) niche is a unique microenvironment. Located in the bone marrow, it regulates HSC behavior in terms of e.g. maintenance, differentiation, proliferation, migration or homing. Understanding the intricate and mutual interactions of HSCs with their niche is a matter of ongoing research with implications in fundamental research and applications in regenerative medicine and drug development.

Using tailor-made biomaterials, others and we could show that besides biological and chemical signals also physical parameters such as nanopatterning, matrix stiffness and 3D architecture influence HSCs in their niche. With the help of these results, we developed a simplified 3D bone marrow analog that allows fundamental studies on HSC-niche interactions and application as a test system to investigate the effects of novel treatments in the HSC niche. As a proof of principle, we studied the efficacy and toxicity of chemotherapeutics in in vitro models of the healthy HSC niche and a leukemic niche model. Thus, we are on the way toward novel, predictive in vitro models of the bone marrow. The possibility of creating patient-specific bone marrow models makes this approach promising as test-system in personalized medicine. Furthermore, the feasibility of parallelization opens the avenue for screening expected effects of novel treatment strategies as well as potential adverse reactions in the bone marrow, which might help to reduce the need for animal experiments in such studies in the future.