Delayed or non-healing bone fractures remain a major clinical problem, especially in older patients, and place a growing financial burden on healthcare systems in Europe. Current strategies such as bone grafting or the use of growth factors have clear limitations, including poor availability, risks of complications, and limited long-term effectiveness. A key obstacle is the inflammatory environment at the defect site, which reduces the regenerative potential of biomaterials.
The METABOLATE project worked intensely on this challenge by developing a novel immuno-engineering approach. The project focused on human macrophages, immune cells that play a central role in inflammation and repair. By metabolically reprogramming macrophages towards a more regenerative state, researchers generated extracellular vesicles with hybrid properties that promote both angiogenesis and osteogenesis. These vesicles were then incorporated into scaffolds, creating immuno-engineered materials designed to modulate inflammation and stimulate bone regeneration. Through this strategy, METABOLATE provides a proof of concept for combining extracellular vesicle biology, immunometabolism, and biomaterials science to develop safer and more effective regenerative therapies for large bone defects.