Regulation of Ce (Ⅲ) / Ce (Ⅳ) ratio of cerium oxide for antibacterial application

Antibiotics have been considered as effective weapons against bacterial infections since they were discovered. However, antibiotic resistance caused by overuse and abuse of antibiotics is an emerging public health threat nowadays. Fully defeating bacterial infections has become a tough challenge. In this work, cerium oxide was fabricated on medical titanium by thermolysis of cerium-containing metal-organic framework (Ce-BTC). Regulation of Ce (Ⅲ)/Ce (Ⅳ) ratios was realized by pyrolysis of Ce-BTC in different gas environment, and the antibacterial properties were studied. The results indicated that, in acidic conditions, ceria with a high Ce (Ⅲ)/Ce (Ⅳ) ratio owned high oxidase-like activity which could produce reactive oxygen species. Moreover, ceria with high Ce (Ⅲ) content possessed strong ATP deprivation capacity which could cut off the energy supply of bacteria. Based on this, ceria with a high Ce (Ⅲ)/Ce (Ⅳ) ratio exhibited superior antibacterial activity.