| Hepatic carcinoma is one of the most pathopoiesis liver diseases in China. It is a difficult disease to diagnose and can only be diagnosed effectively in its early stages. Radiology has played an influential role, especially with magnetic resonance (MR) that has been used extensively to detect hepataceullar carcinoma (HCC). However, the detection rate is not optimistic due to the ambiguity in signals between healthy and cancerous cells. Mecro-supermagnetic iron oxide (MSPIO) is commonly used in biology as a drug delivery vehicle because of its better superparamagnetism and its specific detection of phagocytes in the liver. This results in an improved signal between healthy and cancerous cells. Thus, it is an ideal agent for MR. Researchers have found that the effect of improved signal of MR by MSPIOs was proportional to their size, the size of SPIO is either too large to be sequestered by reticuloendothelial system, or too small that would result in decrease its superparamagnetism.Objective: To manufacture a novel nanometer magnetic particle, SPIO and to investigate its properties as a novel MR agent by detecting of superficial syndrome target superparamagnetism,toxicity and the effects of HCC diagnosis.Methods: (1) Prepare MSPIO by chemical synthesis; (2) detect the superficial syndrome by x-ray and electron microscopy; (3) detect the distributions of MSPIO by Pulu-blue staining and toxic effects by pharmacokinetics and pathology methods; (4) Prepare HCC model by directly injecting H22 cancer cells in liver, and detection with Gd-DTPA and MSPIO, respectively; (5) prepare HCC model with different size cancer nest for comparison of the effects in MR with Gd-DTPA or MSPIO.Results: (1) The size of MSPIO is about 40nm and magnetic intensity is 23KA/m as detected by electron microscope and X-ray. (2) MSPIO was distributed in the liver and the spleen and could be phagocytosed the by reticuloendothelium system. The total number of MSPIO in the body reached the peak at ~1 h after injection, and could not be detected after 3h. (3) Preparation of the HCC model was a success. The MR result of MSPIO confirmed that MSPIO can be used as a novel agent for disease detection and therapy. MSPIO was distributed mostly in the healthy tissues, specially surrounding the cancer. (4) MSPIO was a better agent than Gd-DTPA in the liver for magnetic resonance detection in the liver as shown by the HCC model. (5) MSPIO was better in detecting cancerous cell size within 1mm. Also, the detection rate of MSPIO was 2-3 times better than Gd-DTPA, but has no cleared different at detecting large-size cancer, the detection rate is as 1-1.5 times as Gd-DTPA. Our results reveal that MSPIO was a excellent MR agent in monitoring the cancer growth and it could be phagocytosed by reticuloendothelium system.Conclusion: We have succeeded in preparing MSPIO, which is found to be a novel MR agent by superficial syndrome detecting. MSPIO is better than Gd-DTPA in the detection rate of cancer, and is better in early detection of small size HCC. Also, an in situ model of liver carcinoma was successfully constructed and studied.Our experiments were based on the references at present about SPIO; an aim directed at the present problem that there is no special MR agent could that improve the diagnosis of HCC at present. Thus, we have prepared MSPIO as a solution. Our experiments included a detection system for the novel MR agent, and all the results confirmed our aim that MSPIO can be used as a novel MR agent.
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