Tissue implant-related infections are among the most serious complications after surgical implantation, including orthopedics and dentistry. Implants with antibacterial ion release systems are efficient and economical antibiotic substitutes to fight against bacterial infections. However, the excessive amount of released antibacterial ions may cause biological toxicity while killing bacteria. This raises a fundamental issue on how to properly control the amounts of ions and their efficacy. Here, we develop low-dose antibacterial ions-incorporated ferroelectric implants (copper-doped potassium sodium niobate, K_0.5Na_0.5NbO₃-Cu, KNNCu) whose surface potential can be tuned via external polarization. The released Cu²⁺ ions can be targeted to bacteria via endogenous electric field (EEF) between KNNCu implants and negatively charged bacteria. Intriguingly, the antibacterial efficacy of the implants is determined by the amount of Cu²⁺ ions that reaches bacteria, instead of the total amount of released Cu²⁺ ions. The amount of Cu²⁺ ions reaching bacteria from the high-surface-potential implant is 2.4 times that from the lowsurface- potential implant within 12 h, resulting in the increased antibacterial ratio from about 65% to 100%, while remaining low cell toxicity. This work provides insights into the specific role of the EEF in guiding mass transport between charged materials and living organisms, and a new perspective for the design of high-performance antibacterial biomaterials.

组织植入物相关的感染是外科手术植入后最严重的并发症之一，包括骨科和牙科。具有抗菌离子释放系统的植入物是对抗细菌感染的有效且经济的抗生素替代品。但是，过量释放的抗菌离子可能会在杀死细菌的同时引起生物毒性。这就提出了一个有关如何适当控制离子数量及其功效的根本问题。在这里，我们开发了掺入低剂量抗菌离子的铁电植入物（铜掺杂铌酸钾钠盐，K _0.5 Na _0.5 NbO ₃ -Cu，KNNCu），其表面电位可以通过外部极化来调节。释放的Cu ²⁺离子可通过KNNCu植入物与带负电荷的细菌之间的内源电场（EEF）靶向细菌。有趣的是，植入物的抗菌功效取决于到达细菌的Cu ²⁺离子的量，而不是释放的Cu ²⁺离子的总量。Cu ²⁺的量从高表面电位植入物到达细菌的离子在12小时内是从低表面电位植入物到达细菌的2.4倍，从而使抗菌比从大约65％增加到100％，同时仍保持低细胞毒性。这项工作提供了有关EEF在指导带电材料与活生物体之间的大规模运输中的特殊作用的见解，并为高性能抗菌生物材料的设计提供了新的视角。