0). Biodistribution studies in main excretion organs as well as in popliteal
LN were Performed in male Wistar rats [30 and 90 min post injection (p.i.)]. The injected dose was 0.1 ml (37 MBq) in the footpad of the left https://www.selleckchem.com/products/azd1080.html posterior limb. Dynamic images (0-15 min p.i.) as well as static ones (30 and 90 min) were acquired in gamma camera.
Results: Popliteal LN was clearly reached by all products. Nevertheless, particle size remarkably influenced node uptake. Colloidal rhenium sulfide, with the smallest diameter (5.1 x 10(-3)+/- 3.9×10(-3) mu m), permitted the best result [2.72 +/- 0.64 percent injected dose (%ID) at 90 min]. Phytate displayed small particles (<15 mu m) with favorable uptake (1.02 +/- 0.14%ID). Dextran (21.4 +/- 12.8 mu m) and colloidal tin (39.0 +/- 8.3 mu m) were less effective (0.55 +/- 0.14 and 0.06 +/- 0.03%ID respectively). Particle distribution also tended to influence results. When asymmetric, it was associated with biphasic
uptake which increased over time; conversely, symmetric distribution (colloidal tin) was consistent with a constant pattern.
Conclusion: The results are suggesting that particle size and symmetry may interfere with LN radiopharmaceutical uptake. (C) 2009 Elsevier Inc. All rights reserved.”
“Introduction: The spontaneous copper-free tandem 1,3-dipolar cycloaddition-retro-Diels-Alder (tandem crDA) reaction between cyclic Arg-Gly-ASp-D-Phe-Orn(N-3) Adriamycin cell line [c(RGDfX)] and oxanorbornadiene-DTPA (o-DTPA) or methyloxanorbornadiene-DTPA (mo-DTPA) into two DTPA-c(RGDfX) Electron transport chain regioisomers is characterized. Since there is no information on the stability and reaction rate of the tandem crDA reaction in biological media, we set out to characterize these reaction parameters.
Methods: The effects of concentration of the reactants,
temperature, pH and reaction environment (serum, blood) on the kinetics of the reaction were determined using In-111-labeled oxanorbornadiene-DTPA analogs. The affinity of the radiolabeled conjugate was determined in a solid-phase alpha(v)beta(3) integrin binding assay. Furthermore, the octanol-water partition coefficient was determined and, finally, the biodistribution of the labeled compounds in mice with subcutaneous alpha(v)beta(3)-expressing tumors was determined.
Results: Fifty percent conversion was reached after 26 It. Kinetic experiments furthermore established that the reaction rate of the tandem crDA reaction follows temperature- and concentration-dependent second-order kinetics, but is independent of the pH of the medium. Affinity of the two [In-111]DTPA-cRGDfX conjugates for alpha(v)beta(3) integrin is 191 nM. Biodistribution studies showed Specific (alpha(v)beta(3)-mediated) uptake of [In-111]DTPA-c(RGDfX) in the tumor and in alpha(v)beta(3)-expressing tissues.