Abstract：
Bacterial infections pose a serious threat to human health, with emerging antibiotic resistance, necessitating the development of new antibacterial agents. Cu2+and Ag+are widely recognized antibacterial agents with a low propensity for inducing bacterial resistance; however, their considerable cytotoxicity constrains their clinical applications. Rare-earth ions, owing to their unique electronic layer structure, hold promise as promising alternatives. However, their antibacterial efficacy and biocompatibility relative to conventional antibacterial agents remain underexplored, and the variations in activity across different rare-earth ions remain unclear. Here, we systematically evaluate the antibacterial activity of five rare-earth ions (Yb3+, Gd3+, Sm3+, Tb3+, and La3+) againstStaphylococcus aureusandPseudomonas aeruginosa, benchmarked against well-established antibacterial agents (Cu2+, Ag+) and the antibiotic norfloxacin. Cytotoxicity is also assessed via live/dead staining of fibroblasts after 24 h rare-earth ion exposure. Our findings reveal that rare-earth ions require higher concentrations to match the antibacterial effects of traditional agents but offer the advantage of significantly lower cytotoxicity. In particular, Gd3+demonstrates potent bactericidal efficacy against both planktonic and biofilm bacteria, while maintaining the lowest cytotoxicity toward mammalian cells. Moreover, the tested rare-earth ions also exhibited excellent antifungal activity againstCandida albicans. This study provides a critical empirical framework to guide the selection of rare-earth ions for biomedical applications, offering a strategic direction for the development of novel antimicrobial agents.
摘要：
细菌感染对人类健康构成严重威胁,随着抗生素耐药性的出现，需要开发新的抗菌剂。Cu2+和Ag+是广泛认可的抗菌剂，具有较低的诱导细菌耐药性的倾向；然而，它们相当大的细胞毒性限制了它们的临床应用。稀土离子,由于其独特的电子层结构，把承诺作为有希望的替代方案。然而,它们的抗菌功效和生物相容性相对于常规抗菌剂仍未充分开发，不同稀土离子的活性变化尚不清楚。这里,我们系统地评价了五种稀土离子(Yb3+，Gd3+,Sm3+,Tb3+,和La3）对抗金黄色葡萄球菌和铜绿假单胞菌，以成熟的抗菌剂为基准(Cu2+，Ag+）和抗生素诺氟沙星。在24小时稀土离子暴露后,还通过成纤维细胞的活/死染色来评估细胞毒性。我们的发现表明，稀土离子需要更高的浓度才能与传统药物的抗菌作用相匹配，但具有显着降低细胞毒性的优势。特别是,Gd3+对浮游细菌和生物膜细菌都表现出有效的杀菌效果，同时保持对哺乳动物细胞的最低细胞毒性。此外，测试的稀土离子对白色念珠菌也表现出优异的抗真菌活性。这项研究提供了一个关键的经验框架，以指导用于生物医学应用的稀土离子的选择。为新型抗菌剂的发展提供了战略方向。
