Synthesis and Biomedical Applications of Self-healing Hydrogels.

Yi Liu,Shan-Hui Hsu

doi:10.3389/fchem.2018.00449

Abstract

Hydrogels, which are crosslinked polymer networks with high water contents and rheological solid-like properties, are attractive materials for biomedical applications. Self-healing hydrogels are particularly interesting because of their abilities to repair the structural damages and recover the original functions, similar to the healing of organism tissues. In addition, self-healing hydrogels with shear-thinning properties can be potentially used as the vehicles for drug/cell delivery or the bioinks for 3D printing by reversible sol-gel transitions. Therefore, self-healing hydrogels as biomedical materials have received a rapidly growing attention in recent years. In this paper, synthesis methods and repair mechanisms of self-healing hydrogels are reviewed. The biomedical applications of self-healing hydrogels are also described, with a focus on the potential therapeutic applications verified through in vivo experiments. The trends indicate that self-healing hydrogels with automatically reversible crosslinks may be further designed and developed for more advanced biomedical applications in the future.

Highlights

Hydrogels are constructed by the crosslinked polymer networks as water-swollen gels
Self-healing hydrogels can be classified as robust and soft hydrogels according to mechanical properties in biomedical applications
Robust self-healing hydrogels are used as soft robots with extended lifetime and mechanical performance due to repairing of the damages or fatigues

Summary

Introduction

Hydrogels are constructed by the crosslinked polymer networks as water-swollen gels. Hydrogels have received significant attention as the extracellular matrix mimics for biomedical applications because of their water-retention abilities, appropriate elasticities, and network structures (Wang and Heilshorn, 2015). Self-healing hydrogels can be prepared through dynamic covalent bonds and non-covalent interactions. Self-healing hydrogels have been synthesized based on different chemistries and mechanisms as shown, including dynamic covalent bonds, non-covalent interactions, and multimechanism interactions. The reversible coordinate bond between catechol and iron has been developed to prepare self-healing hydrogels.

Results

Conclusion