Magnetic resonance imaging (MRI) is a non-invasive clinical imaging modality,which has become widely used in the diagnosis of human diseases around the world.Some MRI exams include the use of contrast agents.The goal of an ideal MRI contrast agent involves the tissue-or organ-targeting materials with high relaxivity and specificity,low toxicity and side effects,suitable long intravascular duration and excretion time and high contrast enhancement with low doses,in vivo,all coupled to low overall cost.Dendrimers are synthetic,highly branched,mono-disperse macromolecules of nanometer dimensions.Properties associated with these dendrimers such as uniform size,water solubility,modifiable surface functionality and available internal cavities make them candidates for ideal carriers of MRI contrast agents.The research progress of the dendritic contrast agents is discussed.
YAN GuoPing AI ChaoWu LI Liang ZONG RongFeng LIU Fan
Gadolinium diethylenetriamine-pentaacetic bisdopamide （Gd-DTPA-2DA） was synthesized by the incorporation of dopamine to diethylenetriaminepentaacetic acid （DTPA） and further reaction with gadolinium chloride. In vitro and in vivo properties were also evaluated. Gadolinium complex Gd-DTPA-2DA possessed higher relaxation effectiveness and less cytotoxicity to HeLa cells than that of Gd-DTPA. Moreover, Gd-DTPA-2DA greatly enhanced the contrast of MR images of the brains, provided prolonged intravascular duration, and pro- duced highly contrasted visualization of the brain.
