Injectable scaffold promotes blood vessel and nerve regeneration in mice after stroke

Biomedical engineers at Duke University developed a porous hydrogel scaffold, called MAPS, that can be injected into the tissue void left by an ischemic stroke. By chemically attaching astrocyte-derived extracellular vesicles carrying IL-4 and C1q to the scaffold, the material recruited peripheral immune cells, notably a persistent neutrophil population, which proved essential for new blood-vessel formation and tissue remodeling.

Mice receiving the optimized scaffold showed increased axonal fibers and recovered forelimb coordination, matching the performance of uninjured mice after eight weeks. Control experiments demonstrated that vesicles without the scaffold failed to induce comparable vascular repair, underscoring the importance of the biomaterial’s architecture. Although the results are pre-clinical, the researchers plan to test human-derived astrocyte vesicles and assess safety in larger animal models. The work suggests a new strategy to harness the body’s own repair mechanisms for stroke recovery.