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A peptide microarray-based fluorescence and resonance light scattering ( RLS ) two readout assay was developed for screening thrombin inhibitors in blood samples. In this assay, the biotinylated peptide microarray was used as the platform. The peptide C-terminal fragments carried biotin sites departed from the slide when the biotinylated peptides were digested by thrombin hydrolysis reaction. The hydrolysis progress was labeled by fluorescence and 30 nm peptide-stabilized gold nanoparticles through the biotin-avidin reaction. In the presence of thrombin inhibitors, the hydrolysis reactions were blocked, and the inhibition capability of inhibitors could be detected by the fluorescent and RLS signal changes. The order of the half maximal inhibitory concentration ( IC50 ) of thrombin inhibitors in pure thrombin solution and spiked human serum were argatrobanHAT-Ⅲ>trypsin inhibitor>E-64>AEBSF. The reversible or irreversible characters of argatroban and HAT-Ⅲ had been estimated in human plasma. Compared with the experimental data of fluorescent and RLS assay in blood sample, the RLS assay labeled by 30 nm gold nanoparticles are more suitable for the inhibitor detection in complicated blood sample.
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A gold nanoparticle ( GNP)-based dynamic light scattering ( DLS) assay has been developed for detecting mercury ion ( Hg2+) in aqueous solution. The GNPs are able to maintain monodisperse state in relative high ionic strength ( 0. 1 mol/L NaCl ) aqueous solution because Hg2+ aptamer 5’-TTTCTTCTTTCTTCCCCCCTTGTTTGTTGTTT-3’( Probe DNA ) can adsorb on the GNP surface by electrostatic interaction. In the presence of Hg2+, the Probe DNA molecules easily desorb from GNP surface because of T-Hg2+-T formation. The unprotected GNPs form aggregates in 100 mmol/L NaCl solution, resulting in increased significantly the average hydrodynamic diameter of GNPs. Under the conditions of pH 7. 43, 110 nmol/L aptamer, 100 mmol/L NaCl and 30 minutes incubation time of Hg2+with aptamer, the difference of average hydrodynamic diameter (△D ) of GNPs was increased linearly with logarithm of Hg2+concentration over the range from 0. 1 nmol/L to 5 μmol/L, with a detection limit of 0. 1 nmol/L. Moreover, satisfactory results were obtained when the proposed method was applied to detect Hg2+ in real samples.
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ObjectiveTo investigate the predictor and prophylaxis of cardiovascular events in diabetic nephropathy (DN) patients. MethodsFifty-eight cases of DN patients were assigned randomizedly to two groups. Conventional treatment group(33 cases) received conventional treatment, and ginkgo biloba extract group(30 cases) received extra ginkgo biloba extract capsules treatment. Plasma examination for blood fat, blood pressure(Bp), brain natriuretic peptide(BNP) and echocardiogram was performed every 3 months. All the patients were followed-up for the occurrence of cardiovascular events. ResultsThere were no significant differences in age, sex, Bp, blood fat, serum creatinine, hemoglobin,BNP, left ventricular E/A and left ventricular ejection fraction (LVEF) in two groups at the time of recruitment. After treatment of 12 months, the level of plasma BNP decreased significantly in ginkgo biloba extract group and maintained in the lower levels throughout the follow-up compared with that in conventional treatment group(P＜ 0.01 ). After treatment of 18 and 24 months, left ventricular E/A and LVEF were better in ginkgo biloba extract group than those in conventional treatment group(P ＜ 0.01 or ＜ 0.05 ). In ginkgo biloba extract group, the level of plasma BNP after treatment of 12 months had correlation with left ventricular E/A and LVEF after treatment of 24 months (r =0.61, -0.68, P ＜ 0.05 ). Survival analysis indicated that the level of plasma BNP was a predictor of cardiovascular event in DN patients. ConclusionThe level of plasma BNP can be used as a predictor of cardiovascular event in DN patients,and ginkgo biloba extract capsules can decrease the level of plasma BNP and reduce the incidence of cardiovascular events in DN patients.
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During last decade, gold nanoparticled (AuNPs)-based assays have been well-developed and widely used in biological analysis and biomedical detection because AuNPs have unique physical and chemical properties which depend on the size, shape and degree of aggregation.The AuNPs-based assays have already been employed for detecting practical samples with high simplicity and selectivity.This review discusses the recently development of the synthesis and biological molecular functionalisation of AuNPs and their applications on the heavy metallic cations, small organic compounds, nucleic acids and proteins detection and cellular analysis.