Injectable Supramolecular Hybrid Hydrogel Delivers IL-1β-Stimulated Exosomes to Target Neuroinflammation.

Long-term neuroinflammation is a major barrier to neurological recovery after cerebral ischemia-reperfusion injury (CIRI). Here, a thermosensitive injectable supramolecular hybrid hydrogel is developed to sustainably deliver exosomes derived from interleukin-1β-stimulated bone marrow stromal cells (BMSCs) (βExos) with improved exosome production and anti-inflammatory capacity for neuroinflammation inhibition and neurological recovery. The supramolecular hydrogel displays self-healing and injectable features, along with high biocompatibility and tissue-like softness. The βExos effectively reduce the lipopolysaccharide-induced inflammatory responses in the immortalized mouse microglia (BV2) cell line, and the in situ formed hydrogel improves the exosome retention in the ischemic core area. More remarkably, in the middle cerebral artery occlusion in vivo model, glial scar formation and neuronal loss are significantly reduced by regulating neuroinflammation using the released βExos. Therefore, the combination of interleukin-1β-stimulated exosomes with injectable supramolecular hydrogel provides an appealing strategy for treating central nervous system diseases.