RESUMO
Cyclometalated 1,3-bis(8-quinolyl) phenyl chloroplatinum(II) (Pt1) shows selective luminescence transduction of G-quadruplex binding over duplex DNA. The effect is enhanced on association with parallel and hybrid G-quadruplex structures over other topologies. The kinetics of binding are studied for c-myc and the response is found to be partially reversible in a displacement assay.
Assuntos
Quadruplex G , Platina/química , DNA/química , LuminescênciaRESUMO
Gold supra-pyramid structures were obtained by the addition of acidic solution of cucurbit[8]uril (CB[8]) to an aqueous solution of citrate stabilized gold nanoparticles (AuNP). The reaction resulted in the precipitation of supra-pyramid from the solution after just 1â min of shaking. Microscopic images confirmed formation of the supra-pyramid. The stepwise structural transformation towards the supra-pyramid was examined with variable concentrations of CB[8] to AuNP solution. Anionic counter parts of these acids (Br- , NO3 - , SO4 2- and Cl- ) controlled the size of the synthesized supra-pyramids. These supra-pyramid hosts showed uptake of three anticancer drugs: oral drugs etoposide, prednisolone and intravenous drug doxorubicin. Releases of drugs from these hosts were emulated at acidic stomach pH, basic small intestinal pH and in the presence of human serum albumin (HSA). The specific release of doxorubicin was confirmed at small intestinal pHâ 7.4. Poor release of drugs in presence of CB[8] specific guest 1-adamantanamine confirmed the role of the supra-pyramid as the exclusive host. The release of doxorubicin from the supra-pyramid at pHâ 7.4 was confirmed by fluorescence microscopic imaging with prostate cancer DU-145 cell line.
Assuntos
Hidrocarbonetos Aromáticos com Pontes/química , Doxorrubicina/química , Ouro , Imidazóis/química , Intestino Delgado/química , Nanopartículas Metálicas , Humanos , Concentração de Íons de Hidrogênio , Intestino Delgado/fisiologiaRESUMO
Addition of bis-pyrazole based cryptand regioisomers (1 and 2) to citrate stabilized gold nanoparticles (AuNPs) led to gold supraspheres (AuSSL) and elongated dodecahedron (AuEDL) supraparticles, respectively. These supraparticles as heterogenous hosts show a high uptake of a small fluorophore SEA-SC1 in an aqueous medium and reversible release in organic solvents.
RESUMO
Controlled diluted aqua regia addition leads to NIR (near infrared) luminescence from aggregated gold nanoparticles at 916 nm. This turn-on luminescence has been observed for gold nanoparticles, regardless of reductants used in their preparation. These aggregated nanoparticles are nontoxic and have been used for bioimaging in human liver carcinoma cells.