Recent trends in the development of hydrogel therapeutics for the treatment of central nervous system disorders

The central nervous system (CNS) controls the acquisition and processing of peripheral information to manage the behaviors of organisms. CNS disorders, including CNS injuries, neurodegenerative diseases, and brain tumors, are devastating and can cause life-long disabilities. Despite the advanced medical interventions in the modern era of biomedical technology, noninvasive therapeutic strategies are still limited for the prevention or reversal of disease progression. Such scarcity is mainly caused by intricate pathological mechanisms and the unique biological microenvironment of the CNS. Thus, the development of a carrier that promotes the delivery of therapeutic agents into the brain is vital. Hydrogels, as a synthetic or natural platform with a porous three-dimensional structure, can be applied as desirable drug delivery vehicles and cell transportation platforms. This review focuses on the most recent advancements in hydrogel-based therapies for the treatment of CNS disorders, including brain injury, spinal cord injury, neurodegenerative diseases, and brain tumors.