Semiconductor nanoparticles generate photoelectrons and photo-induced holes under light excitation, and thus may influence the growth of microbial cells. The highly oxidative holes may severely damage the cells, while the photoelectrons may promote microbial metabolism. In this study, we evaluated the effect of exogenous cadmium sulfide (CdS) nanoparticles on bacterial growth using OD₆₀₀ and colony forming unit (CFU) as indicators. The oxidase activities, the concentration of pyruvate and malondialdehyde, and the expression of relevant genes assessed by real-time fluorescent quantitative PCR were analyzed to investigate the effect of excited CdS on cellular metabolism. The results showed that the OD₆₀₀ and pyruvate accumulation of E. coli increased by 32.4% and 34.6%, respectively, under light conditions. Moreover, the relative expression level of the division protein gene ftsZ was increased more than 50%, and the tricarboxylic acid cycle pathway gene icdA and gltA increased by 86% and 103%, respectively. The results indicated that photoelectrons could be used by microorganisms, resulting in promoted growth and metabolism. This study gives a deep insight into the interaction between nanoparticles and bacteria.
Escherichia coli/metabolism* ; Nanoparticles ; Cadmium Compounds/metabolism* ; Quantum Dots

Breast Neoplasms ; metabolism ; pathology ; Cadmium Compounds ; Cell Line, Tumor ; Female ; Humans ; Quantum Dots ; Receptor, ErbB-2 ; analysis ; metabolism ; Selenium Compounds ; Spectrometry, Fluorescence ; Tellurium ; Zinc Compounds

Animals ; Cadmium Compounds ; toxicity ; Cell Proliferation ; Cell Survival ; Cells, Cultured ; Cricetinae ; Cricetulus ; Fibroblasts ; drug effects ; metabolism ; Lactate Dehydrogenases ; metabolism ; Lung ; cytology ; Malondialdehyde ; metabolism ; Quantum Dots

The gamma-cyclodextrin-folate (gamma-CD/FA) inclusion-coated CdSe/ZnS quantum dots (QDs) with folate-receptor (FR) targeted were synthesized by simple and convenient sonochemical method. The products were studied using Fourier transform infrared (FTIR), proton nuclear magnetic resonance (1H NMR), utraviolet-visible spectrometry (UV-vis), fluorescence spectrum and transmission electron micrographs (TEM). The results showed that the gamma-CD/FA-coated CdSe/ZnS QDs not only have good monodispersity and smaller size, but also have good optical performance, such as higher quantum yield (QY) and a long fluorescence lifetime. The cytotoxicity experiments showed that the gamma-CD/FA-coated CdSe/ZnS QDs have lower cytotoxicity and could more effectively enter cancer cells with FR over-expression. The QDs with 4-5 nm in diameter were relatively easy to enter the cell and to be removed through kidneys, so it is more suitable for biomedical applications for bioprobes and bioimaging.
Cadmium Compounds ; chemical synthesis ; chemistry ; metabolism ; toxicity ; Cell Survival ; drug effects ; Folate Receptor 1 ; chemistry ; Folic Acid ; chemistry ; HeLa Cells ; Hep G2 Cells ; Humans ; Magnetic Resonance Spectroscopy ; Microscopy, Electron, Transmission ; Molecular Imaging ; methods ; Quantum Dots ; chemistry ; metabolism ; toxicity ; Selenium Compounds ; chemical synthesis ; chemistry ; metabolism ; toxicity ; Spectrophotometry, Ultraviolet ; Spectroscopy, Fourier Transform Infrared ; Sulfides ; chemical synthesis ; chemistry ; metabolism ; toxicity ; Zinc Compounds ; chemical synthesis ; chemistry ; metabolism ; toxicity ; gamma-Cyclodextrins ; chemistry

OBJECTIVETo synthesize some new alpha-mercapto-beta-substituted aryl acrylic acids, characterize them and investigate their in vitro cadmium chelating ability.

METHODSSix alpha-mercapto-beta-substituted aryl acrylic acids were prepared by the alkaline hydrolysis of 5- (aryl methylene) rhodanines, obtained from the condensation of substituted aldehydes and rhodanine following the reported procedure. The new compounds were characterized by elemental analysis, infrared (IR) and nuclear magnetic resonance (NMR) spectroscopy. The liver and kidney from cadmium chloride pre-administered rats were homogenized and their nuclear mitochondrial fraction (NMF) and supernatant cytosol fraction (SCF) were separated. A measured volume of each fraction was dialyzed separately using "dialysis sack" against buffered-KCl medium containing a compound in the final concentration of 1 x 10(-3) mol/L for 3 h at 37 degrees C. The whole content of "sack" was subjected to cadmium estimation following digestion with conc. Nitric acid was detected using flame atomic absorption spectrometer.

RESULTSThe in vitro screening showed that alpha-mercapto-beta-(p-methoxyphenyl) acrylic acid (compound 2) and alpha-mercapto-beta-(m-methoxy, p-hydroxyphenyl) acrylic acid (compound 4) were more effective than alpha-mercapto-beta-thienyl acrylic acid (compound 1) and alpha-mercapto-beta-(p-dimethylaminophenyl) acrylic acid (compound 3) in mobilizing cadmium as their dialyzable chelates. The presence of a methoxy group on the phenyl moiety (compounds 2 and 4) increases the metal chelating ability of mercapto acrylic acids.

CONCLUSIONSCompounds 2 and 4 seem to have accessibility to the cellular system and capability of chelating-out the intracellularly bound cadmium.

Acrylates ; chemical synthesis ; chemistry ; pharmacology ; Animals ; Cadmium Chloride ; metabolism ; toxicity ; Chelating Agents ; chemical synthesis ; chemistry ; pharmacology ; Injections, Intraperitoneal ; Kidney ; drug effects ; metabolism ; Liver ; drug effects ; metabolism ; Male ; Mitochondria ; drug effects ; metabolism ; Mitochondria, Liver ; drug effects ; metabolism ; Rats ; Sulfhydryl Compounds ; chemical synthesis ; chemistry ; pharmacology