SDF-1 Bound Heparin Nanoparticles Recruit Progenitor Cells for Their Differentiation and Promotion of Angiogenesis After Stroke

Angiogenesis after stroke is correlated with enhanced tissue repair and functional outcomes. The existing body of research in biomaterials for stroke focuses on hydrogels for the delivery of stem cells, growth factors, or small molecules or drugs. Despite the ability of hydrogels to enhance all these delivery methods, no material has significantly regrown vasculature within the translatable timeline of days to weeks after stroke. Here we developed 2 novel biomaterials for tissue regeneration after stroke, a highly porous granular hydrogel termed Cryo microgels, and heparin-norbornene nanoparticles with covalently bound SDF-1α. The combination of these materials resulted in fully revascularized vessels throughout the stroke core in only 10 days, as well as increased neural progenitor cell migration and maintenance and increased neurons.