Nanozymes are considered to represent a new era of antibacterial agents,while their antibacterial efficiency is limited by the increasing tissue depth of infection.To address this issue,here,we report a copper and sil...Nanozymes are considered to represent a new era of antibacterial agents,while their antibacterial efficiency is limited by the increasing tissue depth of infection.To address this issue,here,we report a copper and silk fibroin(Cu-SF)complex strategy to synthesize alternative copper single-atom nanozymes(SAzymes)with atomically dispersed copper sites anchored on ultrathin 2D porous N-doped carbon nanosheets(CuN_(x)-CNS)and tunable N coordination numbers in the CuN_(x) sites(x=2 or 4).The CuN_(x)-CNS SAzymes inherently possess triple peroxidase(POD)-,catalase(CAT)-,and oxidase(OXD)-like activities,facilitating the conversion of H_(2)O_(2)and O_(2)into reactive oxygen species(ROS)through parallel POD-and OXD-like or cascaded CAT-and OXD-like reactions.Compared to CuN_(2)-CNS,tailoring the N coordination number from 2 to 4 endows the SAzyme(CuN_(4)-CNS)with higher multienzyme activities due to its superior electron structure and lower energy barrier.Meanwhile,CuN_(x)-CNS display strong absorption in the second near-infrared(NIR-II)biowindow with deeper tissue penetration,offering NIR-II-responsive enhanced ROS generation and photothermal treatment in deep tissues.The in vitro and in vivo results demonstrate that the optimal CuN_(4)-CNS can effectively inhibit multidrug-resistant bacteria and eliminate stubborn biofilms,thus exhibiting high therapeutic efficacy in both superficial skin wound and deep implant-related biofilm infections.展开更多
基金the National Natural Science Foundation of China(32222041,82072425,82160421,and 82072498)the Natural Science Foundation of Jiangsu Province(BE2020666,BK20211322,and BK20220059)+3 种基金Finland-China Food and Health International Pilot Project funded by the Finnish Ministry of Education and Culture,the Academy Research Fellow(328933)Solutions for Health Strategic Research Profiling Area(336355)InFLAMES Flagship(337531)Grants from Academy of Finland,the Special Project of Diagnosis and Treatment for Clinical Diseases of Suzhou(LCZX202003)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD),and the jiangsu Specially Appointed Professor"Program and Postgraduate Research&Practice Innovation Program of jiangsu Province(KYCX22_3217).
文摘Nanozymes are considered to represent a new era of antibacterial agents,while their antibacterial efficiency is limited by the increasing tissue depth of infection.To address this issue,here,we report a copper and silk fibroin(Cu-SF)complex strategy to synthesize alternative copper single-atom nanozymes(SAzymes)with atomically dispersed copper sites anchored on ultrathin 2D porous N-doped carbon nanosheets(CuN_(x)-CNS)and tunable N coordination numbers in the CuN_(x) sites(x=2 or 4).The CuN_(x)-CNS SAzymes inherently possess triple peroxidase(POD)-,catalase(CAT)-,and oxidase(OXD)-like activities,facilitating the conversion of H_(2)O_(2)and O_(2)into reactive oxygen species(ROS)through parallel POD-and OXD-like or cascaded CAT-and OXD-like reactions.Compared to CuN_(2)-CNS,tailoring the N coordination number from 2 to 4 endows the SAzyme(CuN_(4)-CNS)with higher multienzyme activities due to its superior electron structure and lower energy barrier.Meanwhile,CuN_(x)-CNS display strong absorption in the second near-infrared(NIR-II)biowindow with deeper tissue penetration,offering NIR-II-responsive enhanced ROS generation and photothermal treatment in deep tissues.The in vitro and in vivo results demonstrate that the optimal CuN_(4)-CNS can effectively inhibit multidrug-resistant bacteria and eliminate stubborn biofilms,thus exhibiting high therapeutic efficacy in both superficial skin wound and deep implant-related biofilm infections.
