title: pH-responsive iron manganese silicate nanoparticles as T1-T2* dual-modal imaging probes for tumor diagnosis.
abstract: Magnetic resonance imaging (MRI) probes can be concentrated in tumors through grafting targeting agents. However, the clinical application of such targeted MRI probes is largely limited because specific agents are only used to target specific characteristics of cancer cells. The development of the MRI probes that can be used regardless of tumor types or their developmental stages is highly appreciated. The acidic tumor microenvironments and acidic organelles (endosomes/lysosomes) in cancer cells are universal phenomena of solid tumors, and nanoparticles can also accumulate in tumor tissues by enhanced permeability and retention (EPR) effect. Here, we reported the synthesis of pH-responsive T1-T2* dual-modal contrast agents based on iron manganese silicate (FeMn(SiO4)) hollow nanospheres, which can release Mn(2+) ions in acidic environments, exhibiting excellent ability as agents for magnetic resonance and red fluorescence imaging. MRI for mouse models revealed that the nanoprobes could accumulate in tumors via EPR effect and then distinguish tumors from normal tissues with the synergistic effect of T1 and T2* signal only 10 min after intravenous injection. Fluorescence imaging demonstrated that the nanoprobes could be endocytosed into cancer cells and located at their lower pH compartments. Moreover, the hollow nanospheres showed no obvious toxicity and inflammation to the major organs of mice, which made them attractive diagnostic agents for different types of cancers.
authors: Hefei National Laboratory for Physical Sciences at Microscale, Collaborative Innovation Center of Suzhou Nano Science and Technology, Department of Materials Science & Engineering, CAS High Magnetic Field Laboratory, University of Science and Technology of China , Hefei 230026, China.
authors: Jian
authors: J
authors: Chen
authors: Wei-Jie
authors: WJ
authors: Zhang
authors: Zhen
authors: Z
authors: Guo
authors: Hai-Bao
authors: HB
authors: Wang
authors: Dong-Dong
authors: DD
authors: Wang
authors: Jia-Jia
authors: JJ
authors: Zhou
authors: Qian-Wang
authors: QW
authors: Chen
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D003287:Contrast Media / Q000737:chemistry* / Q000627:therapeutic use / Q000633:toxicity; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007150:Immunohistochemistry; D007501:Iron / Q000737:chemistry; D007668:Kidney / Q000473:pathology; D008099:Liver / Q000473:pathology; D008168:Lung / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008345:Manganese / Q000737:chemistry; D051379:Mice; D008819:Mice, Nude; D018613:Microscopy, Confocal; D053758:Nanoparticles / Q000737:chemistry* / Q000627:therapeutic use / Q000633:toxicity; D009369:Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging; D011859:Radiography; D017640:Silicates / Q000737:chemistry; D014183:Transplantation, Heterologous
chemical_list: D003287:Contrast Media; D017640:Silicates; D008345:Manganese; D007501:Iron
keywords: EPR; T1-T2* weighted image; fluorescence image; iron manganese silicates; pH-responsive