Biology-driven material design for ischaemic stroke repair
Ischaemic stroke remains a leading cause of disability, with current clinical treatment options mainly focusing on mitigating immediate damage. The limited self-renewing capacity of the brain hinders tissue regeneration and prevents full recovery for many patients. However, the injury environment also creates an opportunity for biomaterials to promote inherently reparative phenomena, such as angiogenesis, axonal sprouting and synaptogenesis, and ultimately achieve functional recovery. In this Review, we summarize the dynamic temporal stages of repair following ischaemic stroke that facilitate neural plasticity and outline key physiological phenomena that participate to functional recovery. We then discuss the design of biomaterials, such as injectable hydrogels and granular materials, that can engage and modulate these pro-repair mechanisms in the brain. Such biomaterials can also be engineered to deliver therapeutics, such as proteins, peptides and extracellular vesicles, and provide electrical stimulation. Finally, we outline key challenges that remain to be addressed to translate the preclinical success of biomaterial-based treatment strategies to the clinic.