A cancer-recognizable MRI contrast agents using pH-responsive polymeric micelle

作者：Kim Kyoung Sub; Park Wooram; Hu Jun; Bae You Han^*; Na Kun

来源：Biomaterials, 2014, 35(1): 337-343.

DOI：10.1016/j.biomaterials.2013.10.004

• Cancer diagnosis
• Magnetic resonance imaging
• Micelles
• Imaging agents
• pH-responsive materials

A cancer-recognizable MRI contrast agents (CR-CAs) has been developed using pH-responsive polymeric micelles. The CR-CAs with pH sensitivity were self-assembled based on well-defined amphiphilic block copolymers, consisting of methoxy poly(ethylene glycol)-b-poly(L-histidine) (PEG-p(L-His)) and methoxy poly(ethylene glycol)-b-poly(L-lactic acid)-diethylenetriaminopentaacetic acid dianhydride-gadolinium chelate (PEG-p(L-LA)-DTPA-Gd). The CR-CAs have a spherical shape with a uniform size of similar to 40 nm at physiological pH (pH 7.4). However, in acidic tumoral environment (pH 6.5), the CR-CAs were destabilized due to the protonation of the imidazole groups of p(L-His) blocks, causing them to break apart into positively charged water-soluble polymers. As a result, the CR-CAs exhibit highly effective T-1 MR contrast enhancement in the tumor region, which enabled the detection of small tumors of similar to 3 mm(3) in vivo at 1.5 T within a few minutes.

• 出版日期2014-1