Application Abstract: This project has successfully completed the development of the national standard for the measurement of iron oxide nanoenzyme activity.The macroscopical preparation and quality control of Prussian blue nanoenzyme were successfully achieved by scaling up from 40 mL system to 3 L,10 L and 50 L.The standard material of Prussian blue nanoenzyme was developed.We also developed two novel nucleic acid vectors(cationic polysaccharide nanoparticles and cationic magnetic nanoparticle nucleic acid transfection vectors)that efficiently mediate gene transfection of AML cells.An AML drug-resistant cell specific targeted magnetic nanoprobe with a size of 20 nm was constructed,the design and processing of AML cell magnetic capture microfluidic detection chip was completed,and the development of fluorescence quantitative detector for microfluidic measurement was completed.In addition,we have successfully constructed two novel nanoenzyme that can be used for intracellular ROS regulation:one is a drug-carrying Prussian blue nanoenzyme with double-targeted AML cells,and the other is a composite iron-based nanoenzyme with ultra-small Pt nanoparticles,both of which can effectively target and kill AML cells.We also found that in vitro ferric oxide nanoenzyme combined with cytosine cytosine could promote the apoptosis of leukemia cancer stem cells(LSCs)more strongly than cytosine cytosine monotherapy.The combination of cytarabine and ferric oxide nanoenzyme in vivo has a stronger therapeutic effect on mice with acute myeloid leukemia(AML).