| Literature DB >> 24139764 |
Kyoung Sub Kim1, Wooram Park, Jun Hu, You Han Bae, Kun Na.
Abstract
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 ~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 T1 MR contrast enhancement in the tumor region, which enabled the detection of small tumors of ~3 mm(3 )in vivo at 1.5 T within a few minutes.Entities:
Keywords: Cancer diagnosis; Imaging agents; Magnetic resonance imaging; Micelles; pH-responsive materials
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Year: 2013 PMID： 24139764 DOI： 10.1016/j.biomaterials.2013.10.004
Source DB: PubMed Journal: Biomaterials ISSN： 0142-9612 Impact factor: 12.479