Biocompatible and antibacterial polymers for biomedical applications: a minireview

The global health crisis posed by antimicrobial resistance and biofilm-protected infections demands urgent development of biocompatible antibacterial materials. The traditional antimicrobial substances are challenged by their higher cytotoxicity, poorer biofilm penetration, or resistance induction. This review highlights the transformative potential of highly biocompatible and antibacterial polymers, which achieve broad-spectrum efficacy while minimizing toxicity. The parameter of selectivity index (SI) is emphasized in assessing the balance between antimicrobial efficacy and biocompatibility of antimicrobial materials. A higher SI value indicates that the material retains potent antimicrobial activity while exhibiting superior biocompatibility. Representative examples of antimicrobial materials with high SI values are also summarized. The polymeric quaternary ammonium salts, chitosan derivatives, polyamino acids such as hyperbranched polylysine, and N-halamine polymers demonstrate synergistic antibacterial actions through membrane destabilization, oxidative stress induction, and biofilm suppression, exhibiting tunable degradation, immune tolerance, and selective targeting, enabling applications in medical devices and tissue materials, encompassing both fundamental research and commercial applications in biomedicine, to serve as a comprehensive reference for relevant researchers. Challenges in scalable manufacturing, regulatory classification, and long-term biosafety assessment, and future perspectives on multifunctional polymer design and smart responsive systems are finally discussed.