Biological applications of hydrogel coatings

Hydrogel is a viscoelastic material with a three-dimensional network structure. Due to its good biocompatibility, special porous structure and shape controllability, a hydrogel is widely used in biomedical engineering. The preparation of hydrogel into a coating applied to the surface of the material can endow the material with new characteristics and enhanced performance in a specific environment. While maintaining the characteristics of the original substrate, such as hardness and toughness, the coated materials can also possess the characteristics of hydrogels, such as antibacterial, lubricity, and biocompatibility. Herein, this chapter mainly introduces the working principle and recent research progress of hydrogel coatings for different applications including drug delivery, tissue engineering, implantable materials, and biosensors.