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The interaction between CdSe/ZnS(quantum dots)/TiO2 nanocomposites and human serum albumin(HSA) was investigated by resonance light scattering (RLS) spectroscopic methods under approximate physiological conditions. Much important information of the interaction between CdSe/ZnS(Quantum Dots)/TiO2 nanocomposites and HSA was obtained by studying comprehensively the Exogenous influence factors of nanocomposites concentration, pH, NaCl concentration, reaction temperature, detection time, coexisting ions, surfactants, sequence of adding to the sample etc. It was showed that the new formation of complex system is likely to enhance the protein hydrophobic cavity and tend to focus the hydrophobic interface in aqueous solution, resulting in strengthening the intensity of resonance light scattering; Also it is very sensitive to the changes in the pH value in the system; The sensitivity of I(RLS) in system can be increased by the appropriate NaCl concentration; The value of IRLS in system would be changed with the change in the concentration of coexisting ions; The value of I(RLS) in system is basically stable when the reaction time reaches 5 min; The value of I(RLS) in system is not exactly the same with a surfactant, and strong electrostatic interaction has occurred between oppositely charged surfactant and nano composites; It is obvious that the value of I(RLS) in complex system is affected by the sequence of adding to sample; It has the incomplete monotonically increasing trend with the changes in temperature. The information is useful for providing theoretical supporting for the mechanism of interaction between nanomaterials and bio-macromolecule, and for understanding the biocompatibility and safety of nano-materials.

QDs have large scale application in many important areas with potential of unintentional exposure to the environment or organism during processing of a nanotechnology containing product's life cycle. In this paper, two classical electrochemical methods, cyclic voltammetry and electrochemical impedance spectroscopy were applied to investigate the influence of particle sizes of CdTe QDs on their toxicity targeted to human serum albumin (HSA) under simulative physiological conditions. The results show that the toxicity of yellow emitting QDs (YQDs) on HSA is slightly stronger than that of the green-emitting (GQDs) and red-emitting QDs (RQDs). We also compared these two classical electrochemical methods with the traditional fluorescence spectroscopy through the above results. The electrochemical methods may be more accurate and comprehensive to investigate the toxicity of QDs at the biomacromolecular level under certain conditions, though fluorescence spectroscopy is simpler and more sensitive.

The interaction between 4,4'-diselenadibenzoic acid and human serum albumin (HSA) was investigated by fluorescence and absorption spectroscopy. The quenching mechanism of fluorescence of HSA by 4,4'-diselenadibenzoic acid was discussed. It is proved that the fluorescence quenching of HSA by 4,4'-diselenadibenzoic acid is a result of the formation of the HSA-4,4'-diselenadibenzoic acid complex. The binding sites number n, apparent corporation constant K, and corresponding thermodynamic parameters, deltaH(theta), deltaG(theta), and deltaS(theta) were calculated. Results indicate that the electrostatic interactions forces played major role in the reaction.

Background: Diuretics are commonly used in the intensive care unit (ICU) for patients with fluid over-loading. Hypoalbuminemia is a major cause of diuretic resistance. Albumin mixed with furosemide can promote diuresis and sodium excretion in patients with hypoalbuminemia. The purpose of this study is to compare the diuretic effect of furosemide (FU) mixed with human albumin (HA) or fresh frozen plasma (FFP) in ICU patients with hy-poalbuminemia., Methods: Patients with fluid overloading and hypoalbuminemia who needed diuretic treatment were enrolled and were divided into 2 groups: the first group having clearance of creatinine (CCr) >20 ml/min, and the second group having CCr < or = 20 ml/min. FU (60 mg) mixed with HA (HA group), 60 mg FU mixed with FFP (FFP group) and water (placebo group) were given intravenously to these patients for 60 minutes in random order on the first, third and fifth day. After drug administration, 8-hour urine was collected, and urine amount and urinary sodium excretion were checked., Results: Both the HA group and the FFP group had significantly higher urinary volume and sodium excretion than the placebo group in the patients with CCr >20 ml/min or CCr < or = 20 ml/min (p < 0.01). In the patients with CCr >20 ml/min, there was no difference in the amount of urine excretion and cumulative urinary sodium excretion between the HA group and FFP group. In the patients with CCr < or =ml;20 ml/min, the HA group had a significantly higher urine output and urinary sodium excretion than the FFP group (p < 0.05)., Conclusions: In ICU patients, 60 mg FU mixed with HA or FFP has a similar diuretic effect in patients with CCr >20 ml/min. FFP is an effective alternative choice for improving diuresis for ICU patients with hypoalbuminemia. In patients with CCr < or = 20 ml/min, albumin mixed with 60 mg FU has a superior diuretic effect compared with FFP mixed with FU.

The binding of warfarin to human serum albumin and bovine serum albumin, respectively, was studied by high-performance liquid chromatography (HPLC). Based upon the Hummel - Dreyer method, two techniques were developed: the internal calibration and the external calibration. The results obtained by the HPLC method and those obtained by the classical method (equilibrium dialysis) were compared. The external calibration method seems to be superior to others for its simplicity, speed and convenience.