Hydrogel-mediated drug delivery for treating stroke

Stroke is a common disease and is the major cause of death and disability. It occurs and generates devastating neurological deficits when cerebral blood vessel is blocked (ischemic stroke, IS) or ruptured (hemorrhagic stroke, HS). Hydrogel, being biodegradable and biocompatible, have shown attractive advantages in stroke therapy as a new biomaterial with desirable mechanical properties and tunability of structure, owing to special ability to load different cargoes for multiple treatment strategies, such as pharmacotherapy based on drug-delivery systems and cell therapy including mesenchymal stem cells (MSCs) and neural progenitor cells (NPCs) for improving functional outcomes. However, a comprehensive review of the functional hydrogel for treatment of stroke is still lacking. Therefore, in this work, the main pathological mechanisms of stroke including IS and HS are comprehensively described. The benefits of hydrogel for stroke treatment are also summarized regarding the natural advantages and the delivery advantages. Simultaneously, the application development of hydrogel for treatment of stroke is highlighted. Finally, the unique considerations and challenges in the design and application of hydrogel is discussed for treatment of stroke and clinical application in the future.