BACKGROUND: Liver cancer is one of the most commondiseases around the world. The aim of this study was toverify the effect of magnetic field application on target dis-tribution of nanoparticles in transplanted rat liver cancermodel and to find out a new method for the treatment ofmalignant liver tumor.METHODS: Seven days after the establishment of the mo-del , the abdomen of the rat was exposed through a midlineabdominal incision. A cannula was inserted into the gastro-duodenal artery. In the experimental group ( 12 rats), thetumor tissue was exposed to the magnetic field for 30 mi-nutes. Magnetic albumin nanoparticles containing adriamy-cin or at an equal dose of free adriamycin (0.5 mg/kg)were injected into the hepatic artery. After the magneticfield was removed, the rat was immediately sacrificed. Anequal dose of nanoparticles in absence of the magnetic fieldserved as control (12 rats). Tissues of tumor, nontargetedsites of the liver, heart, kidney, lung, spleen, stomach andsmall intestine were analyzed for γ-counts and examinedhistologically.RESULTS: In the experimental group, the radioactivity oftumor tissue was 8.7 times that of liver tissue. In the con-trol group, the radioactivity of tumor tissue was 2.8 timesthat of normal liver tissue. The radioactivity of the lungwas reduced more significantly in the experimental groupthan in the control group. No significant difference in thekidney, heart, spleen, small intestine and stomach was ob-served between the experimental group and control group.And over 80% of the injected nanoparticles distributed inthe liver.CONCLUSIONS: In the presence of magnetic field, mag-netic albumin nanoparticles may accumulate in tumor tis-sues, of which the radioactivity can increase to 8.7 timesthat of normal liver. Even if the magnetic field is not ap-plied, magnetic albumin nanoparticles in tumor tissues stillincrease to 2.8 times that of normal liver tissues. Thesefindings indicate that normal organs in the presence ofmagnetic field are less exposed to chemotherapeutic drugs. BACKGROUND: Liver cancer is one of the most commondiseases around the world. The aim of this study was toverify the effect of magnetic field application on target dis-tribution of nanoparticles in transplanted rat liver cancer model and to find out a new method for the treatment of malignant liver tumor. METHODS: Seven days after the establishment of the mo-del, the abdomen of the rat was exposed through a midlineabdominal incision. In the experimental group (12 rats), the tumor tissue was exposed to the magnetic field for 30 mi-nutes. Magnetic albumin nanoparticles containing adriamy-cin or at an equal dose of free adriamycin (0.5 mg / kg) were injected into the hepatic artery. After the magnetic field was removed, the rat was immediately sacrificed. Anequal dose of nanoparticles in absence of the magnetic fieldserved as control (12 rats). Tissues of tumor, nontargetedsites of the liver, heart, kidney, lung, spleen, stomach andsmall in The test was for gamma-counts and examinedhistologically. RESULTS: In the experimental group, the radioactivity of tumor tissue was 8.7 times that of liver tissue. The radioactivity of tumor tissue was 2.8 timesthat of normal liver tissue. radioactivity of the lungwas reduced more significantly in the experimental groupthan in the control group. No significant difference in thekidney, heart, spleen, small intestine and stomach was ob-served between the experimental group and control group. And over 80% of the injected nanoparticles distributed inthe liver. CONCLUSIONS: In the presence of magnetic field, mag-netic albumin nanoparticles accum accumulate in tumor tis-sues, of which the radioactivity can increase to 8.7 timesthat of normal liver. Even if the magnetic field is not ap- magnetic albumin nanoparticles in tumor tissues stillincrease to 2.8 times that of normal liver tissues. Thesefindings indicate that normal organs in the presence ofmagnetic fi eld are less exposed to chemotherapeutic drugs.