Hydrogels as carriers deliver stem cells/exosomes for liver injury

Liver injury, both acute and chronic, poses a significant threat to human health, resulting in high morbidity and mortality rates. The current challenges in the treatment of liver injury are limited regenerative capacity and the few donor organs available. However, advancements in biomaterials and regenerative medicine are gradually mitigating these challenges. Hydrogels, with tissue-like properties and biomimetic characteristics, have become highly investigated biomedical materials, which can provide a microenvironment for stem cell survival and enable the controlled slow release of exosomes. Targeted therapy with hydrogel-encapsulated stem cells/exosomes has been demonstrated to promote tissue repair and regeneration. In this review, we first summarise the characteristics and design of hydrogels, emphasizing the design considerations of hydrogels as carriers for the encapsulation of stem cells/exosomes in the treatment of liver injury. We then provide an overview of the hydrogel preparation and administration strategy. Finally, we conclude that injectable hydrogels loaded with stem cells or exosomes are promising for liver tissue regeneration and repair. However, this field is still in its infancy and further research remains imperative. Hydrogels are biomaterials with porous structures, which have the characteristics of slow-release and mimic ECM. Hydrogel-encapsulated stem cells or exosomes can gradually release therapeutic elements and enhance liver regeneration in liver injuries.