Preparation Of Folate Targeted Nanocomposites And Its In Vivo And Vitro MR Imaging

Objective To study the targeting function of folate-conjugated SPIO-DPA (NP-DPA-FA) to hepatoma cells via folate receptor and the feasibility for surveillance of tumor targeting with MRI. Methodsâ‘ At first, the preparation of NP-DPA-FA was completed.â‘¡Microscopic observation with prussian blue staining and ompetitive inhibition were performed in Bel 7402 cells.â‘¢Bel 7402 cells and HL 7702 cells were incubated with NP-DPA-FA for 2 hours, respectively. Prussian blue staining was performed to observe intracellular irons, while MRI was performed to study the signal intensity of cells. Results Much more intracellular irons were observed in Bell 7402 cells incubated with NP-DPA-FA than those in HL 7702 cells. Few intracellular irons were found in Bell 7402 cells by competitive inhibition. The signal intensity of Bel 7402 cells on T2WI decreased significantly with the exaltation of iron concentration in NP-DPA-FA, while no significant reduction of the signal intensity was found in HL 7702 cells. T2 singnal intensity in MRI of Bel 7402 cells decreased by -22.98%,-40.01%, -68.85%, -91.36%,-96.18% respectively and in contrast T2 signal intensity of HL 7702 cells decreased by -4.40%,-5.51%,-17.06%,-33.54% and-39.63% respectively. Conclusion NP-DPA-FA has good targeting ability to Bel 7402 cells in vitro. The cell targeting events could be monitored with MR imaging. Objective To study folate-conjugated SPIO-DPA-Dextran as MR targeting agent to tumor cells via folate receptor, to evaluate feasibility by observing MR signal variations and imaging feature of hepatic carcinoma in nude mice using this contrast material. Methodsâ‘ FeCl3 and sodium oleate was refluxed and yielded oily iron-oleate complex.â‘¡Magnetite nanoparticles was syhthesized via thermal decomposition of iron-oleate under suitable conditions with oleylamine as reducing agent and sodium oleate as surfactant agent.â‘¢Nude mice of subcutaneously transplanted hepatic carcinoma were used as animal models,12 mice were divided into experimental group (n=6) and control group (n=6) randomly. Both were injected with SPIO-DPA-Dextran-FA and SPIO-DPA-Dextran (0.2ml) via caudal vein respectively. Tumor and muscle signal varying was observed after injection of contrast agent 0.5 hour,1 hour,2 hour,4 hour,8 hour,12 hour,18 hour and 24 hour and CNR was calculated at different time points. Resultsâ‘ The composite SPIO-DPA-Dextran-FA exhibited satisfactory dispersibility, and the diameter was 14 nm.â‘¡There was a significant difference (F=146.09,P<0.01) of tumor signal in experimental group and control group. There was no statistic difference (F=3.15,P>0.05)of muscle signal in experimental group and control group .CNR was a significant difference (F=351.39,P<0.01)between experimental group and control group. The maximum intensify of the experiment group appears in 18-24 hours after injection and the control group appears in 0.5-2 hours after injection. Conclusion SPIO-DPA-Dextran-FA shows definite characteristic of tumor targeting effect to nude mice of subcutaneously transplanted hepatic carcinoma . Monitoring and evaluating via MR can help to achieve MR targeted diagnosis.