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Three fullerene isoindoline nitroxides N-methyl-3,4-fulleropyrrolidine-2-spiro-5′- (1′,1′,3′,3′-tetramethylisoindolin-2′-yloxyl), (C60-(TMIO)m, and C70-(TMIO)n) were synthesized by the covalent bonding of 5-formyl-1,1,3,3-tetramethyl isoindolin-2-yloxyl to the fullerenes C60and C70. Significantly, the X-ray photoelectron spectra indicated the characteristic N 1s signals of NO.at 402 eV. The atomic force microscope morphologies showed that the average particle sizes of C60-(TMIO)mand C70-(TMIO)nwere 38 and 15 nm. The electrochemical experiments indicated that fullerene bound isoindoline nitroxides retained similar electrochemical properties and redox reaction mechanisms as the parent nitroxides. The electron paramagnetic resonance spectra of the fullerene isoindoline nitroxides all exhibited the hyperfine splittings and characteristic spectra of tetramethyl isoindoline nitroxides, with typical nitroxide g-values and nitrogen isotropic hyperfine coupling constants. Therefore, these fullerene isoindoline nitroxides may be considered as potential candidates for novel biological spin probes using electron paramagnetic resonance spectroscopy. [ABSTRACT FROM PUBLISHER]

Objective: The specific expression of transferrin receptor can represent a diagnostic tool or therapeutic target in solid tumors expressing this antigen. Herein, the human transferrin receptor monoclonal antibody (T9) was investigated as a tumor-targeting group for active targeted-drug delivery systems. Materials and methods: A tumor-targeted conjugate T9-TNF was synthesized by the attachment of both human transferrin receptor monoclonal antibody (T9) as a tumor-targeting group and human tumor necrosis factor-α (TNF) as an anti-cancer drug to two terminated hydroxyl groups of poly(ethylene glycol). Subsequently, a solvent evaporation technique was adopted to produce anti-cancer magnetic polymer microspheres T9-TNF-PC-M containing T9-TNF and Fe3O4 magnetic ultrafine powders (M) using poly(trimethylene carbonate-co-5,5-dimethyl trimethylene carbonate) (PC, P(TMC-co-DTC)) as a polymeric carrier. Results and discussion: These magnetic polycarbonate microspheres possessed a steady TNF release rate in phosphate buffer saline solution, strong magnetic responsiveness and high T9-TNF loading capacity. In vitro cytotoxicity assays demonstrated the microspheres T9-TNF-PC-M and conjugate T9-TNF were strongly inhibitory to the human hepatic carcinoma (Bel-7204) cells. In vivo site-specific therapy in nude mice with human hepatic carcinoma indicated that the microspheres T9-TNF-PC-M and conjugate T9-TNF possessed markedly higher anti-tumor activity against Bel-7204 in mice than that of TNF. Conclusions: These results indicated that the magnetic polycarbonate microspheres were suitable as the potential-targeted treatment for hepatic carcinoma therapeutics. [ABSTRACT FROM AUTHOR]

The multi-modal imaging contrast agent has been attracted an increased interest to the tumor detecting and diagnosis in these recent years since the multi-modal imaging technology combines the advantages of several medical imaging modalities. A water-soluble fullerenol probe containing glypican-3 monoclonal antibody (GPC3-mAb) group mAb-GPC3-C60(OH)10-(TMIO)3-(NI)3 was synthesized by the incorporation of 5-formyl-1,1,3,3-tetramethylisoindolin-2-yloxyl (FTMIO), naphthalimide (NI) and GPC3-mAb as a tumor-targeting group into fullerenol C60(OH)11. This nanomaterial was further characterized by FTIR, UV, MS, fluorescence, etc., and then its properties including electron paramagnetic resonance (EPR), particle size, electrophoresis, electrochemical assay, cell cytotoxicity, cell uptake and fluorescent imaging of HeLa tumor cells in vitro were also evaluated. Experiment results indicated that mAb-GPC3-C60(OH)10-(TMIO)3-(NI)3 had similar fluorescent properties as NI and similar electrochemical and redox properties as 5-carboxy-1,1,3,3-tetramethylisoindolin-2-yloxyl (CTMIO). Moreover, mAb-GPC3-C60(OH)10-(TMIO)3-(NI)3 possessed low cell cytotoxicity, good fluorescence and good tumor-targeting property. Meanwhile, mAb-GPC3-C60(OH)10-(TMIO)3-(NI)3 can be taken up highly by HeLa tumor cells, achieve good green fluorescent imaging in tumor cells and highly enhance the contrast of fluorescent images. Therefore, mAb-GPC3-C60(OH)10-(TMIO)3-(NI)3 can disperse homogeneously in aqueous solution and be used as a potential tumor-targeting dual-modal contrast agent for EPR imaging/fluorescence imaging (EPRI/FI). [ABSTRACT FROM AUTHOR]

A water-soluble fullerenol containing porphyrin and isoindoline nitroxide groups APTSPP-C60(OH)10-(TMIO)3was synthesized by the incorporation of 5-(4-amino-phenyl)-10,15,20-tris(4-sulfonatophenyl)-porphyrin (APTSPP) as a tumor-targeting group and 5-formyl-1,1,3,3-tetramethylisoindolin-2-yloxyl (FTMIO) into fullerenol C60(OH)11. This nonmaterial was further characterized by FT-IR, UV, MS, TEM, fluorescence, etc. and its properties in vitro were also evaluated. Electrochemical experiments indicated that APTSPP-C60(OH)10-(TMIO)3retained similar electrochemical properties and redox reaction mechanisms as 5-carboxy-1,1,3,3-tetramethylisoindolin-2-yloxyl (CTMIO). Electron paramagnetic resonance (EPR) spectra of APTSPP-C60(OH)10-(TMIO)3exhibited the hyperfine splittings and characteristic spectra of CTMIO, with typical nitroxide g-values and nitrogen isotropic hyperfine coupling constants. In vitro cytotoxicity assay showed APTSPP-C60(OH)10-(TMIO)3possessed low cytotoxicities to human renal tubular epithelial 293T cells and HepG-2 cells. Therefore APTSPP-C60(OH)10-(TMIO)3may be considered as a potential candidate for novel biological spin probe using EPR spectroscopy. [ABSTRACT FROM AUTHOR]

Diethylenetriaminepentaacetic di(L-dopa ethyl ester) ligand (DTPA-2LDEE) was synthesized by reaction between diethylenetriaminepentaacetic dianhydride (DTPAA) and L-dopa ethyl ester (LDEE). This ligand reacted with gadolinium chloride and sodium pertechnetate to make the corresponding neutral gadolinium complex Gd-DTPA-2LDEE and technetium-99m-labeled complex99mTc-DTPA-2LDEE, respectively. The ligand and complexes were characterized and their propertiesin vitroandin vivowere also evaluated. Gd-DTPA-2LDEE possessed higher relaxation effectiveness and lower cytotoxicity to human hepatoma HepG-2 cells than Gd-DTPA.99mTc-DTPA-2LDEE had enhanced single-photon emission computed tomography (SPECT) signal enhancements of the kidneys in rats and provided longer duration time than that of99mTc-DTPA. Therefore,99mTc-DTPA-2LDEE can be selectively excreted by the kidneys and used as a potential radioactive probe in SPECT. [ABSTRACT FROM AUTHOR]