dextran-based nanomicelle system with directly ester-bound gadolinium chelates as a magnetic resonance imaging contrast agent for tumor detection

There is a strong need to develop mri contrast agents (cas) with lower in-vivo retention, stronger signal enhancement, and more specific imaging. here, we report a novel dextran (dex)-based nanomicelle system as an mri ca with superior tumor imaging and relatively short intravascular persistence. gadolinium (gd)-chelate (dtpa-gd) was conjugated directly to dex hydroxyl via a degradable ester bond. dex-dtpa-gd was then modified with dodecylsuccinic anhydride to obtain the amphiphilic derivative, 2-dodecylsuccinic acid (dsa)- grafted dex-dtpa-gd. nanomicelles were prepared by dissolving dsa-dex-dtpa-gd in water using ultrasonication. the physicochemical properties, cytotoxicity, and mri efficiency of the synthesized ca were evaluated. the synthesized dsa-dex-dtpa-gd self-assembled into nanomicelles with an average diameter of 67.80 ± 5.21 nm. within the given gd concentration range, dsa-dex-dtpa-gd and magnevist® exhibited similar cytotoxicity. dex-based cas resulted in a greater contrast enhancement of t1-weighted signal intensity in the tumor region than magnevist®, and the tumors were clearly defined for at least 3 h. simultaneously, the ester bond in dsa-dex-dtpa-gd facilitated the elimination of gd chelates, compared with the relatively more stable amide linker. the dex-based nanomicelle system with directly ester-bound dtpagd may serve as an mri ca with superior tumor imaging and relatively rapid elimination.