Engineering principles of zwitterionic hydrogels: Molecular architecture to manufacturing innovations for advanced healthcare materials

Zwitterionic hydrogels have garnered significant attention for their exceptional anti-fouling properties and biocompatibility. These materials have been further enhanced through the incorporation of highly crosslinked 3D networks, endowing them with novel physicochemical characteristics such as stimuli-responsive swelling, ion conductivity, and antibacterial capabilities. In certain cases, zwitterionic motifs can impart self-healing properties for hydrogels, potentially paving the way for the development of functional biomaterials that closely mimic biological tissues. In recent years, we have witnessed substantial efforts from the scientific community to harness the potential of zwitterionic hydrogels for various biomedical applications. This review offers a comprehensive examination of the design principles underlying these materials, spanning from molecular engineering aspects to recent advancements in synthesis routes and fabrication methods. The discussion encompasses the advantages and limitations of different preparation processes, as well as prospects for zwitterionic hydrogels. As a result, this review aims to provide valuable insights for researchers and engineers working to optimize zwitterionic hydrogels for specific biomedical applications, including drug delivery, tissue engineering, and biosensors.