Mesoporous silica nanocapsules loaded liposomes negatively enhance magnetic resonance T2 weighted imaging / 第二军医大学学报

ABSTRACT

Objective To detect the relaxation property of mesoporous silicananocapsules loaded liposomes (MSN-LIPO), and to explore their functions of enhancing MRI T2 weighted imaging. Methods In vitro, MSN-LIPO with different ironconcentrations were scanned by MRI system to detect their relaxation properties. In vivo, six BALB/c nude mouse models with subcutaneous malignant glioma were established and randomly divided into two groups, which were injected with the same concentration of MSN-LIPO intratumorally and intravenously, respectively. The mice in the two groups were scanned by MRI before and after injection, and the image characteristicswere studied and the signal intensity of tumors was statistically analyzed. Results In vitro MRI imaging showed that the signal intensities of the images were gradually decreased with the increase of iron concentrations in MSN-LIPO, and 1/T2 had a good linear relationship with the concentration within a certain range, with the relaxation rate (r2) being 413.7 mmoL-1 s-1. MRI imaging of BALB/ c nude mouse models with malignant glioma showed that the signal intensity of the tumor after intratumor injection of MSN-LIPO was significantly lower than that before intra-tumor injection (15.34±1.24 vs 211.44 ± 5.34, t=36.38, P < 05), and the signal intensity of the tumor after intravenous injection of MSN-LIPO was significantly lower than that before intravenous injection (179.00 ± 4.35 vs 235.99 ± 5.17, t=14.34, P <0.05). Conclusion MSN-LIPO has good magnetic relaxation property and good MRI T2 weighted contrast enhancement function in vivo, suggesting that it can be used as a MRI T2 contrast agent.