Y(2)O(3) nanocrystals (YO NC) doped
check details in situ with fluorescent (Eu(3+)) and paramagnetic (Gd(3+)) impurities and conjugated with a potential cancer targeting ligand, folic acid (FA), were prepared using an all-aqueous wet-chemical process. Structural, optical and magnetic properties of these multifunctional nanocrystals were investigated by X-ray diffraction, electron microscopy, photoluminescence and magnetization studies. Highly monodisperse nanocrystals of size similar to 20 nm with cubic bixbyite crystal structure showed bright red-fluorescence when doped with Eu(3+). Co-doping with Gd(3+) and mild air drying resulted significantly enhanced fluorescence quantum efficiency of similar to 60% together with paramagnetic functionality, enabling T(1)-weighted MR contrast with similar to 5 times higher spin-lattice relaxivity compared to the clinically used Gd(3+) contrast agent. Cytotoxicity and reactive oxygen stress studies show no toxicity by YO NC in both normal and cancer cells up to higher doses of 500 mu M and longer incubation time, 48 h. Cancer targeting
capability of FA conjugated NCs was demonstrated on www.selleckchem.com/products/mek162.html folate receptor positive (FR+) human nasopharyngeal carcinoma cells (KB) with FR depressed KB (FRd) and FR negative (FR-) lung cancer cells A549 as controls. Fluorescence microscopy and flow-cytometry data show highly specific binding and cellular uptake of large concentration of FA conjugated NCs on FR+ve cells compared to the controls. Thus, the present study reveals, unique bi-modal contrast imaging capability, non-toxicity and cancer targeting capability of multiple impurities doped rare-earth
oxide nanocrystals that can find promising application in molecular imaging. (C) 2009 Elsevier Ltd. All rights reserved.”
“Mechanisms that bring about coordination of cell growth and cell division in different organisms are biological events not yet clearly revealed. In maize, insulin effector of the phosphatidylinositol 3-kinase (PI3K)-target of rapamycin (TOR) signal transduction pathway in metazoan or an intrinsic maize growth factor similar to insulin has shown to regulate cell growth. CA3 research buy This research has been undertaken to analyze the role of PI3K-TOR signal transduction pathway in maintaining coordinated regulation of cell growth and cell division in maize tissues. Results indicate that DNA synthesis as well as mitotic index increased in maize callus in vitro cultures after insulin or maize factor stimulation. Biomass and ribosomal protein synthesis also showed significant increment after this stimulation, and the cell morphology composition of the cultures drastically changed. Two proteins related to cell cycle, D-type cyclins and proliferating cell nuclear antigen, were selectively synthesized under these conditions.