Visualising superfine cerebrovasculature in MRI using supramolecular self-assembly

点击翻译按钮获取中文摘要

Iron oxide nanoparticles (IONPs) are promising contrast agents in terms of their high T1/T2 relaxation time and biocompatibility. However, IONPs easily accumulate in the liver and possess shorter circulation time. Therefore, microvessel imaging is not possible with them. Nanoparticles size between ~100 to 200 nm should be optimal to achieve maximum stability and longer circulation time. Firstly, we have synthesized fluorescein/Fe3O4 conjugated PEG that can form supramolecular self-assemble structure by the fluorescein groups stacked with one another. We have performed different characterization test as FTIR, UV-spectra and XPS to confirm the synthesis. Dynamic light scattering (DLS) analysis has been performed to confirm the change in hydrodynamic radius. Further we have evaluated self-assemble structure stability with different time, pH and temperature. Fluorescein conjugation enhance stability of self-assembly structure at normal pH, and the structure get disintegrated in alkaline pH. Moreover, blood circulation test and organ accumulation analysis have performed on small animal. These results were presented at 44th annual meeting of Japanese Society of Biomaterials (JSB), and 72nd annual meeting of Society of Polymer Science Japan (SPSJ).