02308nas a2200217   4500008004100000022001400041245011600055210006900171260007100240300001400311490000700325520147400332100002501806700002201831700002001853700001901873700003001892700002001922700001801942856013001960       2009                        eng d  a0743-746300aDendritic effect of ligand-coated nanoparticles: enhanced apoptotic activity of silica-berberine nanoconjugates0 aDendritic effect of ligandcoated nanoparticles enhanced apoptoti  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcFEB  a2339-23470 v253 a<p>We describe the synthesis and biological characterization of a novel prototype, namely, silica nanoconjugates bearing a covalently linked berberine, a plant alkaloid known to have antiproliferative activity. The effect of synthesized nanoconjugates on cell proliferation, the cell cycle profile, and apoptosis in the human cervical carcinoma cell line (HeLa), human hepatocellular liver carcinoma cell line (HepG2), and human embryonic kidney (HEK) 293T cell line has been studied and compared with the results obtained for free berberine. Our results show that all the nanoconjugates display higher antiproliferative activity than free berberine. The ability of these nanoconjugates to inhibit cellular proliferation is mediated by the cell cycle arrest at the G1 phase. Moreover, silica nanoconugates caused selective apoptotic arrest with a higher efficiency than free berberine followed by apoptotic cell death as shown by quantitative fluorescence-activated cell sorting analyses. Efficiency of the nanoconjugates increases upon an increase in the linker chain length, demonstrating the distinct role of the spacer chain that conjugates nanoparticles and ligands. The actual reason to show enhanced efficiency by the nanoconjugates has not been elucidated in the present study; however, we hypothesize that an increase in local concentration due to the confinement of a ligand on the nanosurface (''dendritic'' effect) might have led to the observed effect.</p>1 aHalimani, Mahantappa1 aChandran, Prathap1 aKashyap, Sudhir1 aJadhav, V., M.1 aPrasad, Bhagavatula L. V.1 aHotha, Srinivas1 aMaiti, Souvik  uhttp://library.ncl.res.in/content/dendritic-effect-ligand-coated-nanoparticles-enhanced-apoptotic-activity-silica-berberine-0