Objectives: The use of antiangiogenic therapy in conjunction with traditional chemotherapy is becoming increasingly in cancer management, but the optimal benefit of these targeted pharmaceuticals has been limited to a subset of the population treated. Improved imaging probes that permit sensitive detection and high-resolution characterization of tumor angiogenesis could improve patient risk-benefit stratification. The overarching objective of these experiments was to develop a dual modality alpha(nu)beta3-targeted nanoparticle molecular imaging agent that affords sensitive nuclear detection in conjunction with high-resolution MR characterization of tumor angiogenesis.
View Article and Find Full Text PDFThree 1,4,7,10-tetraazacyclododecane-N,N',N",N"'-tetraacetic acid (DOTA) analogues were evaluated for relative in vivo stability when radiolabeled with (111)In, (90)Y and (177)Lu and conjugated to the monoclonal antibody B72.3. The DOTA analogues evaluated were "NHS-DOTA" [N-hydroxysuccinimdyl (NHS) group activating one carboxylate], "Arm-DOTA" (also known as MeO-DOTA; with a p-NCS, o-MeO-benzyl moiety on the methylene group of one acetic acid arm) and "Back-DOTA" (with a p-NCS-benzyl moiety on a backbone methylene group of the macrocycle).
View Article and Find Full Text PDFThis report describes a preliminary study to investigate the effect of structural variations in a bifunctional ligand being developed for targeted PARACEST applications. Utilizing Eu-DOTA-4AmCE as the functional PARACEST core, a nitro-aromatic functionality was incorporated to provide the point for conjugation. This intermediate possesses a coordinated water proton signal at 57 ppm which upon saturation produces a 22% decrease in bulk water signal intensity using 10 mM agent.
View Article and Find Full Text PDFEarlier tumor detection can improve 5-year survival of patients, particularly among those presenting with cancers less than 1 cm in diameter. alpha(nu)beta(3)-Targeted (111)In nanoparticles (NP) were developed and studied for detection of tumor angiogenesis. Studies were conducted in New Zealand white rabbits implanted 12 days earlier with Vx-2 tumor.
View Article and Find Full Text PDFA lipid-encapsulated perfluorocarbon nanoparticle molecular imaging contrast agent that utilizes a paramagnetic chemical exchange saturation transfer (PARACEST) chelate is presented. PARACEST agents are ideally suited for molecular imaging applications because one can switch the contrast on and off at will simply by adjusting the pulse sequence parameters. This obviates the need for pre- and postinjection images to define contrast agent binding.
View Article and Find Full Text PDFThe radiolanthanides 149Pm, 166Ho, and 177Lu have decay characteristics suitable for radioimmunotherapy (RIT) of cancer. N-Hydroxysulfosuccinimidyl DOTA (DOTA-OSSu) and methoxy-DOTA (MeO-DOTA) were conjugated to the anti-TAG-72 monoclonal antibody CC49 for radiolabeling with 149Pm, 166Ho, and 177Lu. While both DOTA conjugates could be labeled to high specific activity with 177Lu, MeO-DOTA afforded superior conjugate stability, radiolabeling, and radiochemical purity.
View Article and Find Full Text PDFSince the advent of Ziegler-Natta polymerization of ethylene, attempts have been made to extend coordination polymerization to commercially important monomers with polar functionality. In this study we examined the copolymerization of perdeuterated vinyl chloride (VC) and perdeuterated vinyl acetate (VA) with ethylene using a tridentate Fe(II) dichloride pyridine diimine metal catalyst. The resulting ethylene oligomers were examined by GC/MS and 2H NMR spectroscopy.
View Article and Find Full Text PDFThis report outlines a new and efficient synthesis of cyclen (1,4,7,10-tetraazacyclododecane, 1) utilizing bis-imidazoline, 6 (1,1'-ethylenedi-2-imidazoline), with 1,2-dibromoethane. General conditions were developed, allowing for the simple, three-step synthesis of 1 at the multigram scale with an isolated overall yield approaching 65%. The cyclization of 6 produced by the condensation of triethylene tetraamine (TETA) with N,N-dimethylformamide dimethyl acetal, gave the twelve-membered, imidazolinium, cyclized intermediate bromide salt, 7 (2,3,4,5,6,7,8,8c-octahydro-1H-4a,6a,8a-triaza-2a-azoniacyclopent[fg]acenaphthylene), which hydrolyzed to 1 with the use of hot, aqueous caustic.
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