Development of an Enzymatic Biosensor Using Glutamate Oxidase on Organic-Inorganic-Structured, Electrospun Nanofiber-Modified Electrodes for Monosodium Glutamate Detection.

Herein, dendrimer-modified montmorillonite (Mt)-decorated poly-Ɛ-caprolactone (PCL) and chitosan (CHIT)-based nanofibers were prepared. Mt was modified with a poly(amidoamine) generation 1 (PAMAMG1) dendrimer, and the obtained PAMAMG1-Mt was incorporated into the PCL-CHIT nanofiber's structure. The PCL-CHIT/PAMAMG1-Mt nanofibers were conjugated with glutamate oxidase (GluOx) to design a bio-based detection system for monosodium glutamate (MSG). PAMAMG1-Mt was added to the PCL-CHIT backbone to provide a multipoint binding side to immobilize GluOx via covalent bonds. After the characterization of PCL-CHIT/PAMAMG1-Mt/GluOx, it was calibrated for MSG. The linear ranges were determined from 0.025 to 0.25 mM MSG using PCL-CHIT/Mt/GluOx and from 0.0025 to 0.175 mM MSG using PCL-CHIT/PAMAMG1-Mt/GluOx (with a detection limit of 7.019 µM for PCL-CHIT/Mt/GluOx and 1.045 µM for PCL-CHIT/PAMAMG1-Mt/GluOx). Finally, PCL-CHIT/PAMAMG1-Mt/GluOx was applied to analyze MSG content in tomato soup without interfering with the sample matrix, giving a recovery percentage of 103.125%. Hence, the nanofiber modification with dendrimer-intercalated Mt and GluOx conjugation onto the formed nanocomposite structures was performed, and the PCL-CHIT/PAMAMG1-Mt/GluOx system was successfully developed for MSG detection.

Testing of bioactive-nanovesicles on hepatotoxicity of atypical antipsychotics via digital holography.

Atypical antipsychotic drugs induce hepatic toxicity. Thus, it is of importance to eliminate the side effects of these drugs. Herein we describe the preparation of nanoemulsions with a dietary supplement; wheat germ oil (WGO), to ameliorate the liver damage induced by clozapine and olanzapine. THLE-2 cell line was used as a model to investigate the effects of these nanoemulsions on cell viability as well as antioxidative efficiency after antipsychotic insult. In this context, a conventional cell culture method; MTT was used along with a novel cellular imaging technique called digital holography (DH) to evaluate cell viability. Obtained data confirmed that both clozapine and olanzapine induced the liver damage in in vitro model and WGO nanoemulsions were found to be effective on cells and eliminate the cytotoxic effects of these drugs. Briefly, this study has some outputs as follows; it showed that different dietary supplements can be used in such formulations instead of their pristine forms to increase bioavailability. Also, DH was successfully applied for the monitoring of cell viability and it could be a promising approach as the reactive-free cytotoxicity test.

Rhodamine functionalized conducting polymers for dual intention: electrochemical sensing and fluorescence imaging of cells.

We report here the electrochemical co-polymerization of two functional monomers, one containing fluorescent rhodamine dye (RF) and the other monomer having amine groups (RD), onto electroactive Indium Tin Oxide (ITO) glass. After one step preparation of these surfaces, a three peptide called ArginylGlysylAspartic acid (RGD) was immobilized via EDC chemistry by using amine groups (P(RF-co-RD)/RGD) of the co-polymer, for further use in various bio-applications such as cell adhesion and imaging as well as electrochemical cell sensing. The resultant RGD bound and also fluorescent platforms were utilized as targeted adhesion materials towards integrin avb3 receptor positive (U87-MG) cells and the selectivity was checked by using HaCaT cells as a control. Finally, electrochemical measurements were carried out to characterize step by step surface modification and detection of cell attachment. As a result, P(RF-co-RD)/RGD is a promising material for multi-purpose uses, such as fluorescence imaging without the need for an additional dye for cell visualization and as a targeted adhesion and electrochemical cell sensing platform.