title: Magnetic resonance imaging contrast agent: cRGD-ferric oxide nanometer particle and its role in the diagnosis of tumor.
abstract: To construct tumor-targeted nanometer particles as a negative magnetic resonance imaging (MRI) contrast agent. Ultra-small superparamagnetic iron oxide (USPIO) nanometer particles were prepared by one-step chemical precipitation. The covalent bond between cyclic RGD (cRGD) containing an Arg-Gly-Asp sequence targeting integrin-alphavbeta3, and USPIO was conducted by chemical crosslinking. The physico-chemical property of cRGD-USPIO was detected. Prussian blue staining was applied to detect the specific binding capacity of cRGD-USPIO and USPIO to human pulmonary adenocarcinoma A549 cells and human umbilical vein endothelial cells. Subsequently, A549 xenografts in nude mice were established, and intravenous injections of USPIO and cRGD-USPIO into the vena caudalis were performed. The enhancement of cRGD-USPIO against tumor MRI signal was evaluated. The mean hydrodynamic diameter of cRGD-USPIO was 43.97 +/- 10.10 nm and the size of the ferric oxide core was 5-10 nm. The specific saturation magnetization was 59.94 A x m2 x Kg(-1). The cell conjugation assay results indicated that the positive staining of the cRGD-USPIO group was significantly enhanced. The in vivo MRI diagnosis indicated that the cRGD-USPIO tumor signal was significantly reduced compared to that of the USPIO group (P < 0.01). The targeted superparamagnetic iron oxide nanometer particle can be a novel MRI negative contrast agent for more specific tumor early diagnosis.
authors.affiliation: Department of Pathology, Tongji Hospital, Tongji University School of Medicine, Shanghai 200065, China.
authors.forename: Xianghua
authors.initials: X
authors.lastname: Yi
authors.forename: Yongmei
authors.initials: Y
authors.lastname: Ding
authors.forename: Yu
authors.initials: Y
authors.lastname: Zeng
authors.forename: Caicun
authors.initials: C
authors.lastname: Zhou
authors.forename: Benfang
authors.initials: B
authors.lastname: Luo
authors.forename: Shuyan
authors.initials: S
authors.lastname: Meng
authors.forename: Weiwei
authors.initials: W
authors.lastname: Rui
authors.forename: Yinmin
authors.initials: Y
authors.lastname: Zhao
authors.forename: Wei
authors.initials: W
authors.lastname: Li
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D003287:Contrast Media; D005290:Ferric Compounds / Q000737:chemistry*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D053768:Metal Nanoparticles; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009369:Neoplasms / Q000175:diagnosis*; D009842:Oligopeptides / Q000737:chemistry*
chemical_list: D003287:Contrast Media; D005290:Ferric Compounds; D009842:Oligopeptides; C000499:ferric oxide; C047981:arginyl-glycyl-aspartic acid