Mussel-inspired chemistry: A promising strategy for natural polysaccharides in biomedical applications

Polysaccharides are a kind of natural biopolymers and have been widely applied in various fields, especially biomedical applications, due to their fascinating properties, such as renewability, structural diversity, biodegradability and biocompatibility. However, pristine polysaccharides sometimes fail to meet the requirements in biomedical applications. Chemical modifications offer a significant means of changing the physical and chemical properties of polysaccharides and enhancing their functionalities. The traditional modification methods mainly include selective oxidation, carboxymethylation, acetylation, phosphorylation, sulfation, “Click” reactions and polymer grafts. In recent years, mussel-inspired chemistry has emerged as a novel, simple and efficient strategy to modify natural polysaccharides, therefore endowing them with some new and unique properties and broaden their applications in biomedicine. This strategy can give polysaccharides with outstanding adhesive performance, oxidation resistance, antibacterial property, coating capacity, high reactivity, chelating and coordinating abilities, bioactivities, and biological compatibility, and also affords a significant surface modification platform for the fabrication of diverse hybrid materials with specific functionalities. This review summarizes the methods (including surface chemistry and covalent conjugate) to modify various natural polysaccharides (including cellulose, chitin, chitosan, alginate, hyaluronic acid, heparin, starch, etc.) via mussel-inspired chemistry, and discusses their various biomedical applications such as tissue engineering, hemostasis, wound healing, drug delivery, antibacterial, chemo-photothermal therapy, biosensors and 3D bioprinting. This work is expected to give a better understanding of opportunities and challenges of mussel-inspired strategy for the functionalization of polysaccharides in biomedical applications. It can envision that mussel-inspired strategy will continuously attract attention in the modification of polysaccharides and more significant applications will be explored.