Strategies for enhancing mechanical performances of long-term zwitterionic biomedical implants

Zwitterionic polymers exhibit outstanding antifouling properties due to their strong hydration capabilities through ionic solvation, making them highly suitable for biomedical implants interfaces. However, their weak mechanical strength poses significant challenges for sustained physiological functionality. This review explores strategies to enhance the mechanical performance of zwitterionic materials, focusing on intermolecular interaction strengthening via combination of different chemical and physical interactions, chain structural design and nanofiller reinforcement. Recent applications of zwitterionic materials with strengthened mechanical properties in interface coatings, zwitterionic hydrogels, zwitterionic modified polymers (biomedical polymers) and design of carboxybetaine (CB) ester hydrophobic analogues are discussed. Additionally, we evaluate the advantages and disadvantages of these approaches in achieving durable, antifouling implants and highlight the need for standardized in vivo evaluations to bridge laboratory research and clinical translation. By systematically analyzing recent advances, this work provides insights into balancing mechanical robustness with biofunctionality for next-generation zwitterionic biomedical implants.