Manganese-loaded dual-mesoporous silica spheres for efficient T1- and T2-weighted dual mode magnetic resonance imaging.
A novel class of manganese-based dual-mode contrast agents (DMCAs) based on the core-shell structured manganese-loaded dual-mesoporous silica spheres (Mn-DMSSs) for simultaneous T1- and T2-weighted magnetic resonance imaging (MRI) has been successfully reported. The in vitro MR tests demonstrate that the Mn-based DMCAs display an excellent simultaneous T1-weighted and T2-weighted MR imaging effect with a noticeably high T1 relaxivity (r1) of 10.1 mM(-1) s(-1) and a moderately high T2 relaxivity (r2) of 169.7 mM(-1) s(-1). The Mn-based DMCAs exhibit negligible cytotoxicity with >80% cell viability at a concentration of up to 200 μg/mL in human liver carcinoma (HepG2) and mouse macrophage (RAW264.7) cells after 24 h. Confocal laser scanning microscopy (CLSM) results show that the Mn-DMSSs were internalized via endocytosis and located in the cytoplasm but not in the nucleus. The in vivo experiment shows that the signals of rat liver increased by 29% under T1-weighted imaging mode and decreased by 28% under T2-weighted imaging mode in 5 min postinjection of Mn-DMSSs, which reveal that the novel Mn-loaded DMSSs can be used as both positive (T1-weighted) and negative (T2-weighted) MR contrast agents in further biomedical applications.
Lab of Low-Dimensional Materials Chemistry, Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology , Shanghai 200237, P. R. China.
Dechao
D
Niu
Xiaofeng
X
Luo
Yongsheng
Y
Li
Xiaohang
X
Liu
Xia
X
Wang
Jianlin
J
Shi
D000179:Acrylates / Q000138:chemical synthesis / Q000737:chemistry; D000818:Animals; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D003287:Contrast Media / Q000737:chemistry* / Q000633:toxicity; D003593:Cytoplasm / Q000378:metabolism; D004705:Endocytosis; D056945:Hep G2 Cells; D006801:Humans; D008279:Magnetic Resonance Imaging; D008345:Manganese / Q000737:chemistry*; D051379:Mice; D011137:Polystyrenes / Q000138:chemical synthesis / Q000737:chemistry; D016062:Porosity; D012822:Silicon Dioxide / Q000737:chemistry*
D000179:Acrylates; D003287:Contrast Media; D011137:Polystyrenes; C509855:poly(styrene-b-acrylic acid); D008345:Manganese; D012822:Silicon Dioxide