Recent trends in natural polymer-based hydrogels for biomedical applications

Hydrogels with large specific surface area, high water content, tissue similarity, three-dimensional bionic structure, adjustable conductive path, stimulus responsiveness and many other excellent characteristics have become the most potential candidate for biomedical applications. Among them, hydrogels derived from natural polymers are arousing wide attention due to its excellent biological activity and distinctive physicochemical properties. Hence, this review concentrates on the recent trends in natural polymer-based hydrogels in the field of biomedical applications. First, we give a summary of the common natural materials for hydrogel fabrications, including polysaccharides, proteins, and polyphenols. Next, we discuss the design strategies of natural polymer-based hydrogels based on the physical or chemical cross-linking reactions. Then, we outline the fundamental functions of natural polymer-based hydrogels required for biomedical applications. Further, we summarized the representative biomedical applications of natural polymer-based hydrogels. Finally, we make concluding commentaries on the challenges and prospects about natural polymer-based hydrogels for biomedical applications. We hope this review will provide insightful information for future development of natural polymer-based hydrogels for biomedical applications.