Iron oxide/manganese oxide co-loaded hybrid nanogels as pH-responsive magnetic resonance contrast agents. (June 2015)

• Record Type: Journal Article
• Authors: Wang, Xia; Niu, Dechao; Wu, Qing; Bao, Song; Su, Teng; Liu, Xiaohang; Zhang, Shengjian; Wang, Qigang
• Is Part Of: Biomaterials. Volume 53(2015)
• Page Start: 349
• Page End: 357
• Publication Date: 2015-06
• Subjects: Nanogel -- Magnetic resonance imaging -- Acid-responsive -- Superparamagnetic iron oxide particles -- Manganese species; Biomedical materials -- Periodicals; Biocompatible Materials -- Periodicals; Biomatériaux -- Périodiques; 610.28
• DOI: 10.1016/j.biomaterials.2015.02.101
• Languages: English
• ISSNs: 0142-9612

Abstract

Abstract: This work described a proof of concept study of hybrid nanogel-based magnetic resonance contrast agents, SPIO@GCS/acryl/biotin@Mn-gel, abb. as SGM, for highly efficient, pH-responsive T1 and T2 dual-mode magnetic resonance imaging (MRI). SGM have been synthesized by assembling superparamagnetic iron oxide particles into polysaccharide nanoclusters, followed by in-situ reduction of the manganese species on the clusters and a final mild polymerization. The dual-mode SGM showed an interesting pH-responsiveness in in vitro MRI, with both T1 and T2 relaxivities turned "ON" in the acidic environment, along with an increase in the r1 and r2 relaxivity values by 1.7-fold (from 8.9 to 15.3 mM −1 S −1 ) and 4.9-fold (from 45.7 to 226 mM −1 S −1 ), due to desirable silencing and de-silencing effects. This interesting acidic-responsiveness was further verified in vivo with both significantly brightened signal of tumor tissue in T1 -weighted MR images and a darkened signal in T2 -weighted MR images 50 min post-injection of SGM. This smart hybrid nanogel may serve as a promising candidate for further studies of dual-mode (T1 and T2 ) contrast agents in MRI, due to its high stability, interesting pH-response mechanism and indicative imaging of tumors.