Preparation of Novel Biocompatible Macromolecular Magnetic Resonance Imaging Contrast Agent / 分析化学

Poly ( aspartic acid-co-leucine) was synthesized, modified via ethylenediamine, conjugated with 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) and finally chelated with gadoliniumⅢ, yielding PL-A2-DOTA-Gd. The T1-relaxivity (15. 3 mmol-1 ·L·s-1 ) of PL-A2-DOTA-Gd was 2. 6 times than that of Gd-DOTA (5. 8 mmol-1·L·s-1) in D2O. The results of magnetic resonance imaging experiments showed significant enhancement in the rat liver after intravenous administration of PL-A2-DOTA-Gd, which persisted longer than Gd-DOTA. The mean percentage enhancements of liver parenchyma were 65. 1%±5. 2%and 21. 3%±4. 9%, for PL-A2-DOTA-Gd and Gd-DOTA, respectively.