Construction of a ternary nano-architecture based graphene oxide sheets, toward electrocatalytic determination of tumor-associated anti-p53 autoantibodies in human serum.

Almost 13% of all death in the world is related to cancer. One of the major reasons for failing cancer treatment is the late diagnosis of the tumors. Thus, diagnosis at the early stages could be vital for the treatment. Serum autoantibodies, as tumor markers, are becoming interesting targets due to their medical and biological relevance. Among them, anti-p53 autoantibody in human sera is found to be involved in a variety of cancers. Regarding this issue, a novel and sensitive electrochemical biosensor for detection of anti-p53 autoantibody has been developed. For this purpose, a nanocomposite including thionine (as an electron transfer mediator)/chitosan/nickel hydroxide nanoparticles/electrochemically reduced graphene oxide (Th-CS-Ni(OH)2NPs-ERGO) as a support platform was fabricated on the surface of glassy carbon electrode via a layer-by-layer manner and characterized through common electrochemical and imaging techniques. Then, p53-antigen was immobilized on the nanocomposite and used in an indirect immunoassay with horseradish peroxidase (HRP)-conjugated secondary antibody and H2O2 as the substrate, following the typical Michaelis-Menten kinetics. Under optimized condition, two techniques, including differential Pulse Voltammetry (DPV) and Electrochemical Impedance Spectroscopy (EIS) as a label free technique, applied for the biomarker detection. The linear ranges and LODs were obtained 0.1-500 pg mL-1 and 0.001 pg mL-1 using DPV and 5-150 pg mL-1 and 0.007 pg mL-1 using EIS, respectively. Furthermore, the proposed biosensor displayed satisfying stability, selectivity, and reproducibility. According to the results, the presented protocol is promising to develop other electrochemical biosensors.

Crosslinked-polyvinyl alcohol-carboxymethyl cellulose/ZnO nanocomposite fibrous mats containing erythromycin (PVA-CMC/ZnO-EM): Fabrication, characterization and in-vitro release and anti-bacterial properties.

Recently, nanocomposite nanofibers have been extensively used for biomedical applications. It is expected that simultaneous incorporation of antibiotic drugs and ZnO nanoparticles into nanofiber resulted in providing the synergistic anti-bacterial effect. The main aim of the present study is to fabricate polyvinyl alcohol (PVA)/carboxymethyl cellulose (CMC)-ZnO nanocomposite fibrous mats containing erythromycin (EM) drug and crosslink them using 2% glutaraldehyde vapor and 3% AlCl3 alcoholic solution. The fabricated nanofibers characterized via TGA, FTIR, TEM, and SEM, indicating that the addition of ZnO nanoparticles and EM molecules into the fabricated nanofibers resulted in changing their average diameter. Their anti-bacterial activity was studied against S. aureus and E. coli and found that PVA-CMC/ZnO-EM nanofibers show excellent antimicrobial activity. In-vitro release profile showed that EM release from PVA-CMC/ZnO-EM nanofibers was slowly increased. Sustained drug release profile and excellent anti-bacterial activity of PVA-CMC/ZnO-EM nanofiber indicated that it was an ideal biomaterial for wound dressings.

Electrochemical Synthesis and Kinetic Evaluation of Electrooxidation of Acetaminophen in the Presence of Antidepressant Drugs.

With the aim of obtaining information about drug-drug interaction (DDI) between acetaminophen and some of antidepressant drugs (fluoxetine, sertraline and nortriptyline), in the present work we studied the electrochemical oxidation of acetaminophen (paracetamol) in the presence of these drugs by means of cyclic voltammetry and Controlled-potential coulometry. The reaction between N-acetyl-p-benzoquinone-imine (NAPQI) produced from electrooxidation of acetaminophen and antidepressant drugs (see scheme 1) cause to reduce the concentration of NAPQI and decreases the effective concentration of antidepressants. The cyclic voltammetric data were analyzed by digital simulation to measure the homogeneous parameters for the suggesting electrode mechanism. The calculated observed homogeneous rate constants [Formula: see text] for the reaction of electrochemically generated N-acetyl-para benzoquinn-imine with antidepressant drugs was found to vary in the order [Formula: see text] > [Formula: see text] > [Formula: see text] at biological pH.