Smart, Bio‐Inspired Polymers and Bio‐Based Molecules Modified by Zwitterionic Motifs to Design Next‐Generation Materials for Medical Applications

In philosophy, yin and yang symbolize opposing and simultaneously correlated forces. This pre‐defined scenario occurs in nature as well, e.g., for zwitterionic materials. Both charges, either positive or negative, act individually, and it is not surprising that their interaction with, for example, tissue surfaces or cell membranes differs. However, the combination of the individual binding affinities allows for establishing and tuning strong and/or surface‐specific interactions. To emphasize this relationship, this review describes novel, naturally‐derived and bio‐inspired (semi‐)synthetic materials with zwitterionic motifs designed for medical applications. Accordingly, it is not only mentioned how these materials are further modified, functionalized, or synthetically designed to obtain zwitterionic charge profiles for addressing various pathological scenarios. It is equally important to highlight how the physicochemical properties of zwitterions contribute to achieving this goal. For this purpose, the detailed understanding and basic knowledge of mediated binding mechanisms and electrostatic interactions of zwitterionic materials with the physiological, aqueous environment and body/artificial surfaces are discussed in‐depth to clarify the dynamics of zwitterionic moieties.