Zwitterionic choline phosphate functionalized chitosan with antibacterial property and superior water solubility

As a biocompatible natural polymer material, chitosan (CS) is widely used in biomedical fields due to its excellent properties such as antibacterial ability. However, the main drawback of chitosan is that it cannot dissolve in water, seriously limiting its application in biomedical field. In this study, CS was successfully modified with a zwitterionic 2-(methyl acryloyoxy) ethyl choline phosphate (MCP) monomer by Michael addition reaction to obtain choline phosphate functionalized chitosan (CS-MCP). The CS-MCP exhibited an excellent water solubility. The antibacterial activity of CS-MCP was tested against S. aureus and E. coli in vitro, the results indicated that the antibacterial property of CP-MCP dissolved in water was as well as that of CS dissolved in acetic acid. The studies of cytotoxicity and hemolysis of CS-MCP showed that CS-MCP had excellent cytocompatibility and low hemolysis ratio. Thus, the water soluble chitosan derivative CS-MCP with good antibacterial ability and biocompatibility has great potential in biomedicine.