This study was to develop a new method for detecting circulating tumor cells (CTCs) with high sensitivity and specificity, therefore to detect the colorectal cancer as early as possible for improving the detection rate of the disease. To this end, we prepared some micro-column structure microchips modified with graphite oxide-streptavidin (GO-SA) on the surface of microchips, further coupled with a broad-spectrum primary antibody (antibody1, Ab₁), anti-epithelial cell adhesion molecule (anti-EpCAM) monoclonal antibody to capture CTCs. Besides, carboxylated multi-walled carbon nanotubes (MWCNTs-COOH) were coupled with colorectal cancer related antibody as specific antibody 2 (Ab₂) to prepare complex. The sandwich structure consisting of Ab₁-CTCs-Ab₂ was constructed by the microchip for capturing CTCs. And the electrochemical workstation was used to detect and verify its high sensitivity and specificity. Results showed that the combination of immunosensor and micro-nano technology has greatly improved the detection sensitivity and specificity of the immunosensor. And we also verified the feasibility of the immunosensor for clinical blood sample detection, and successfully recognitized detection and quantization of CTCs in peripheral blood of colorectal cancer patients by this immunosensor. In conclusion, the super sandwich immunosensor based on micro-nano technology provides a new way for the detection of CTCs, which has potential application value in clinical diagnosis and real-time monitoring of disease.
Humans ; Nanotubes, Carbon/chemistry* ; Neoplastic Cells, Circulating/pathology* ; Biosensing Techniques ; Immunoassay/methods* ; Antibodies ; Colorectal Neoplasms/diagnosis* ; Electrochemical Techniques/methods* ; Gold/chemistry*

p-Nitrophenylphosphate (PNPP) is usually employed as the substrate for enzyme-linked immunosorbent assays. p-Nitrophenol (PNP), the product of PNPP, with the catalyst alkaline phosphatase (ALP), will passivate an electrode, which limits applications in electrochemical analysis. A novel anti-passivation ink used in the preparation of a graphene/ionic liquid/chitosan composited (rGO/IL/Chi) electrode is proposed to solve the problem. The anti-passivation electrode was fabricated by directly writing the graphene-ionic liquid-chitosan composite on a single-side conductive gold strip. A glassy carbon electrode, a screen-printed electrode, and a graphene-chitosan composite-modified screen-printed electrode were investigated for comparison. Scanning electron microscopy was used to characterize the surface structure of the four different electrodes and cyclic voltammetry was carried out to compare their performance. The results showed that the rGO/IL/Chi electrode had the best performance according to its low peak potential and large peak current. Amperometric responses of the different electrodes to PNP proved that only the rGO/IL/Chi electrode was capable of anti-passivation. The detection of cardiac troponin I was used as a test example for electrochemical immunoassay. Differential pulse voltammetry was performed to detect cardiac troponin I and obtain a calibration curve. The limit of detection was 0.05 ng/ml.
Electrochemical Techniques/methods* ; Electrodes ; Graphite ; Immunoassay/methods* ; Ink ; Microscopy, Electron, Scanning ; Troponin I/blood*

Paracetamol was used as a model drug in this study to investigate the synergetic effects of lipid coating and beta-cyclodextrin (beta-CD) inclusion for masking the bitter taste of poorly soluble drugs. To control the concentration as low as possible of the free drug which produced a bitter taste, a kinetic model was established to calculate the drug distribution theoretically among the free drug in medium, lipid coated particles and molecular inclusion on the basis of the preparation and characterization of the lipid microspheres, so as to select the proper amount of beta-CD. Finally, the synergetic drug delivery systems were prepared and characterized by 1H nuclear magnetic resonance (1H NMR), molecular simulation and the electronic tongue. As a result, the drug release rate constant (k) of the lipid microspheres coated with octadecanol was determined as 0.001 270 s(-1). Then, the synergetic drug delivery systems were prepared with the ratio of 6.74 : 1 (w/w) for beta-CD and paracetamol. The chemical shift values for the fingerprint peaks of paracetamol all increased and hydrogen bonds were formed between the oxygen on the phenolic hydroxyl group, the nitrogen on the imino in paracetamol and the hydrogens on the hydroxyl groups in beta-CD. The results tested by the electronic tongue indicated that the paracetamol, lipid microspheres, beta-CD inclusion and their mixture showed different taste characteristics, with the bitterness order of the synergetic drug delivery systems approximately lipid microspheres < beta-CD inclusion < paracetamol, which confirmed the synergetic taste masking effects of lipid coating and beta-CD molecular inclusion. In summary, the synergetic taste masking was jointly achieved through the retard of the drug release by the lipid coating and the inclusion of the free paracetamol by beta-CD through hydrogen bonds.
Acetaminophen ; administration & dosage ; chemistry ; Administration, Oral ; Drug Delivery Systems ; Electrical Equipment and Supplies ; Electrochemical Techniques ; instrumentation ; methods ; Hydrogen Bonding ; Kinetics ; Lipids ; chemistry ; Microspheres ; Solubility ; Taste ; drug effects ; beta-Cyclodextrins ; chemistry

In this study, we investigated reductive degradation of nitroaromatic antibiotic chloramphenicol to non-effective antibacterial amine product in fed-batch biocatalyzed electrolysis systems (BES) (applied voltage was 0.5 V) under low temperature (12 +/- 2 degrees C). The ohm resistance of the whole BES reactor increased when the phosphate buffer solution concentrations decreased. Efficiencies (ErCAP) of chloramphenicol reduction with biocathode (PBS, 25 mmol/L) in presence of glucose was (86.3 +/- 1.69)% within 24 h and sludge fermentation liquor was (74.1 +/-1.44)% within 24 h. While the ErCAP of abiotic cathode under the same condition was only (57.9 +/- 1.94)% within 24 h. It suggested that biocathode could be a promising technology for reductive biodegradation of nitroaromatic antibiotics-containing wastewater in areas with relatively low annual mean temperature.
Bioreactors ; Chloramphenicol ; metabolism ; Electrochemical Techniques ; instrumentation ; methods ; Electrodes ; Fermentation ; Oxidation-Reduction

To establish an electrochemiluminescence immunoassay (ECLIA) for the detection of influenza virus B (Flu B), we biotinylated the Flu B monoclonal antibody (mAb),labeled the paired Ab with ruthenium and used the streptavidin-coated microparticles in this study. The ECL intensity was linear with the concentrations of antigen of Flu B in the range of 0.55 microg/mL to 17.5 microg/mL, with a detection limit of 0.55 microg/mL (S/N= 3). The precision,sensitivity and specificity were evaluated. The established ECLIA for Flu B antigen in this study was specific, sensitive and precise. It may provide a convenient and rapid technique for clinical detection of Flu B.
Antibodies, Viral ; analysis ; Electrochemical Techniques ; Immunoassay ; methods ; Influenza B virus ; isolation & purification ; Luminescence

We studied the interaction between proteins and polystyrene-polyacrylic acid (PS-PAA) spherical polyelectrolyte brushes with different polyacrylic acid (PAA) chain lengths, including the physical adsorption and chemical adsorption in PBS buffer. Results showed that the amount of bovine serum albumin (BSA) physically adsorbed on PS-PAA spherical polyelectrolyte brushes decreased to a minimum of 33 microg/mg whereas the amount of streptavidin (SA) chemically adsorbed increased with the increase of chain length and carboxyl quantity. The biotin binding capacity of streptavidin chemically adsorbed on PS-PAA spherical polyelectrolyte brushes was roughly evaluated via enzyme competitive inhibition.
Acrylic Resins ; chemistry ; Adsorption ; Biosensing Techniques ; Electrochemical Techniques ; methods ; Electrolytes ; chemistry ; Polyamines ; Polymers ; chemistry ; Polystyrenes ; chemistry ; Proteins ; chemistry ; Serum Albumin, Bovine ; chemistry ; Surface Properties

Using brain microdialysis and LC-ECD, the content of dopamine in rat brain was detected to investigate the effects of ligustrazine. A liquid chromatography-electrochemical detector method has been established and validated for the determination of dopamine in rat brain dialysate. The results indicate that ligustrazine administration by subcutaneous injection significantly increased dopamine release in rat medial prefrontal cortex, nucleus accumbens and hippocampus in a dose-related manner. The drug's effects on dopa release in rat brain could be directly detected by microdialysis combined with HPLC-ECD and this method has the preponderance over traditional neurology methods.
Animals ; Brain ; metabolism ; Chromatography, High Pressure Liquid ; Dopamine ; metabolism ; Dose-Response Relationship, Drug ; Electrochemical Techniques ; Hippocampus ; metabolism ; Injections, Subcutaneous ; Ligusticum ; chemistry ; Male ; Microdialysis ; methods ; Nucleus Accumbens ; metabolism ; Plant Roots ; chemistry ; Plants, Medicinal ; chemistry ; Prefrontal Cortex ; metabolism ; Pyrazines ; administration & dosage ; isolation & purification ; pharmacology ; Rats ; Rats, Sprague-Dawley

Animals ; Electrochemical Techniques ; methods ; Gene Silencing ; Genes, Reporter ; Humans ; MicroRNAs ; blood ; genetics ; metabolism ; physiology ; Microarray Analysis ; RNA, Messenger ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction

This paper is aimed to evaluatethe thyroglobulin autoantibody (TgAb) interference in measurement of thyroglobulin (Tg) between electrochemiluminescent assay (ECLIA) and radioimmunoassay (RIA). Tg and TgAb of 84 sera, including 22 Graves' hyperthyroidism(GD), 24 Hashimoto thyroiditis (HT) and 38 differentiated thyroid carcinomas (DTC), were measured by RIA and ECLIA, respectively. Recovery tests were carried out in 3 groups. The sera samples of the first group were added 3 different amount of Tg calibrator; the sera samples of the second group were diluted 5 times, then 100 ng/ml Tg calibrator was added; the sera samples of the third group were divided into different subgroups depending on TgAb concentration with adding 100 ng/ml Tg calibrator,Tg and TgAb were measured in each dilution by ECLIA and RIA. Recovery rate was calculated. The Tg and TgAb values measured by ECLIA were correlated with that measured by RIA (r = 0.676, P = 0.000; r = 0.677, P = 0.000, respectively). When TgAb concentration increased, the Tg values decreased by ECLIA and increased by RIA. The TgAb values were decreased when sera were diluted, and the Tg values also reduced by RIA and increased by ECLIA. The added different amount of Tg calibrator had not significant influence on Tg recovery rates. When TgAb concentration increased, recovery rates of Tg were decreased by ECLIA and increased by RIA. When sera were diluted, the recovery rates of Tg were increased by ECLIA while decreased by RIA. RIA and ECLIA have good correlation with Tg measurement in 10-400 ng/ml. ECLIA has wider measuring range and higher sensitivity than RIA. RIA and ECLIA have good correlation with TgAb measurement. When TgAb is positive, Tg values are underestimated by ECLIA and overestimated by RIA. When sera are diluted, Tg value and the recovery rate are increasing by ECLIA and decreased by RIA. Recovery test can not efficiently rectify Tg value when TgAb is positive.
Adolescent ; Adult ; Aged ; Autoantibodies ; blood ; Child ; Electrochemical Techniques ; Female ; Graves Disease ; blood ; Hashimoto Disease ; blood ; Humans ; Luminescent Measurements ; methods ; Male ; Middle Aged ; Radioimmunoassay ; methods ; Thyroglobulin ; blood ; immunology ; Thyroid Neoplasms ; blood ; Young Adult

OBJECTIVETo investigate the clinical effect of electrochemical therapy (ECT) combined with pingyangmycin (PYM) injection for the treatment of high-return flow venous malformation.

METHODSA total of 68 cases of the high-return flow venous malformation were retrospectively analyzed, in which 32 cases received simplely ECT,and 36 cases received ECT combined with PYM injection. The patients were followed up from 6 to 30 months.

RESULTSThe effectiveness of ECT was 78% (25/32), and of ECT combined with PYM injection was 97% (35/36). The effectiveness of ECT combined with PYM injection was higher than that of ECT (P < 0.05). No serious adverse effects were encountered.

CONCLUSIONSECT combined with PYM injection is an effective method for the treatment of high-return flow venous malformation.

Adolescent ; Adult ; Aged ; Bleomycin ; administration & dosage ; analogs & derivatives ; therapeutic use ; Blood Flow Velocity ; Child ; Child, Preschool ; Combined Modality Therapy ; Electrochemical Techniques ; methods ; Female ; Follow-Up Studies ; Humans ; Injections ; Male ; Middle Aged ; Retrospective Studies ; Vascular Malformations ; drug therapy ; physiopathology ; therapy ; Veins ; abnormalities ; Young Adult