State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, China.
Biomater Sci. 2019 Jun 25;7(7):2833-2840. doi: 10.1039/c9bm00057g.
Bacteria can increase drug resistance by forming bacterial biofilms. Once the biofilm is formed, it becomes difficult to remove or kill the related bacteria completely by antibiotics and other antibacterial agents because these antibacterial agents cannot easily break through the biofilm matrix barrier and reach the internal bacteria. Therefore, we synthesized magnetite hybrid nanocomplexes that can penetrate and disrupt bacterial biofilms. The obtained nanocomposites are composed of multinucleated iron oxides and Ag seeds. The outer iron oxides can help the internal Ag nanoparticles penetrate the bacterial biofilms, hence killing the internal bacteria and disrupting the biofilms. We took advantage of E. coli and P. aeruginosa bacteria to test the antibacterial properties of the magnetite hybrid nanocomplexes. When planktonic E. coli and P. aeruginosa bacteria were incubated with 100 μg mL-1 magnetite hybrid nanocomplexes for 30 min, almost all the bacteria were killed. When the obtained biofilms of E. coli and P. aeruginosa were treated with magnetite hybrid nanocomplexes (10 μg mL-1 and 100 μg mL-1), the survival of E. coli and P. aeruginosa biofilms with a magnetic field showed a big decrease compared with that without a magnetic field. Therefore, the as-synthesized nanocomposites have promising potential as antimicrobial agents for killing bacteria and disrupting biofilms in the presence of a magnetic field, and thus should be further studied for a wide range of antibacterial applications.
细菌可以通过形成细菌生物膜来增加药物耐药性。一旦形成生物膜，抗生素和其他抗菌剂就很难完全去除或杀死相关细菌，因为这些抗菌剂不容易穿透生物膜基质屏障到达内部细菌。因此，我们合成了可以穿透和破坏细菌生物膜的磁性杂化纳米复合物。所得到的纳米复合物由多核氧化铁和 Ag 种子组成。外部的氧化铁可以帮助内部的 Ag 纳米颗粒穿透细菌生物膜，从而杀死内部细菌并破坏生物膜。我们利用大肠杆菌和铜绿假单胞菌来测试磁性杂化纳米复合物的抗菌性能。当浮游大肠杆菌和铜绿假单胞菌与 100μg mL-1 的磁性杂化纳米复合物孵育 30 分钟时，几乎所有的细菌都被杀死了。当大肠杆菌和铜绿假单胞菌的生物膜用磁性杂化纳米复合物（10μg mL-1 和 100μg mL-1）处理时，磁场下大肠杆菌和铜绿假单胞菌生物膜的存活率与无磁场相比有显著下降。因此，所合成的纳米复合材料具有在磁场存在下作为抗菌剂杀死细菌和破坏生物膜的巨大潜力，因此应该进一步研究其在广泛的抗菌应用中的潜力。
