title: Mono-dispersed high magnetic resonance sensitive magnetite nanocluster probe for detection of nascent tumors by magnetic resonance molecular imaging.
abstract: Sensitive molecular imaging and detection of tumors or their supporting neovascularity require high-avidity, target-specific probes, which produce robust signal amplification compatible with a sensitive high-resolution imaging modality. In this context, we fabricated a high magnetic resonance (MR)-sensitive magnetite nanocluster (MNC) probe specific for tumor angiogenesis by assembly of hydrophobic superparamagnetic iron oxide nanoparticles (SPIONs) with (Mal)mPEG-PLA copolymer into cluster and subsequent encoding c(RGDyC) peptide on the cluster (RGD-MNC) for detection of nascent tumors. We found that RGD-MNC is highly sensitive (r(2) = 464.94 s(-1)mM(-1)) and specific for αvβ3-positive cells. Both nascent (35 ± 6.6 mm(3)) and large tumors (256 ± 22.3 mm(3)) can be registered by RGD-MNC and detected by MR imaging (MRI), with the nascent tumors demonstrating more pronounced MR contrast. Immunohistochemical studies revealed that MR signal decrease was closely correlated with histological characteristics of tumors (microvessel density and αvβ3 expression levels) at different growth stages.
authors.affiliation: cfzhang@sjtu.edu.cnSchool of Biomedical Engineering and Med-X Research Institute, Shanghai Jiao Tong University, Shanghai, People's Republic of China.
authors.forename: Chunfu
authors.initials: C
authors.lastname: Zhang
authors.forename: Xuan
authors.initials: X
authors.lastname: Xie
authors.forename: Sheng
authors.initials: S
authors.lastname: Liang
authors.forename: Mingli
authors.initials: M
authors.lastname: Li
authors.forename: Yajie
authors.initials: Y
authors.lastname: Liu
authors.forename: Hongchen
authors.initials: H
authors.lastname: Gu
mesh_terms: D000818:Animals; D003287:Contrast Media; D008279:Magnetic Resonance Imaging / Q000379:methods*; D058185:Magnetite Nanoparticles; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D057054:Molecular Imaging / Q000379:methods*; D015336:Molecular Probe Techniques; D015335:Molecular Probes / Q000187:drug effects*; D009374:Neoplasms, Experimental / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D058185:Magnetite Nanoparticles; D015335:Molecular Probes