The Recent Applications of Stem Cell-Derived Exosomes and Hydrogels in Neurological Disorders

Neurological disorders such as Alzheimer's disease, Parkinson's disease, and stroke pose significant challenges for conventional therapy due to the complexities of the blood-brain barrier (BBB) and the restricted delivery of drugs to the central nervous system. Exosomes, a type of small extracellular vesicle secreted by nearly all cell types, hold substantial promise as delivery vehicles for therapeutic agents in treating these conditions. Notably, stem cell-secreted exosomes have emerged as particularly effective due to their regenerative potential and natural ability to cross the BBB. Similarly, hydrogels have gained recognition as versatile biomaterials capable of supporting sustained release and targeted delivery of therapeutics. The combination of the regenerative properties of stem cell-derived exosomes (SC-Exos) with the structural and functional benefits of hydrogels offers a promising approach for enhancing neurogenesis, modulating neuroinflammation, and facilitating tissue repair. This review explores the origin, structure, and modifications of exosomes as well as the synthesis and incorporation methods of hydrogels in the therapeutic context for debilitating neurological disorders. It highlights recent advancements in using SC-Exos and hydrogels for therapeutic delivery, addressing both current challenges and future applications. Improving our understanding of hydrogels loaded with SC-Exos for cargo transportation and neural tissue regeneration may pave the way for novel therapeutic strategies.Impact StatementIn this review, we critically appraise the innovative use of stem cell-derived exosomes (SC-Exos) combined with hydrogels for treating neurological disorders, focusing on their dual role in therapeutic cargo delivery and tissue regeneration. We provide a comprehensive overview of the current methods for exosome isolation, stem cell sources, cargo loading techniques, type of hydrogels and their synthesis, exosome-hydrogel incorporation methods, and preclinical applications. This article also offers insights into the current advancements, future trends, and challenges in SC-Exos-loaded hydrogels for neural regeneration and suggests improvements for future research.