Cytotoxicity of Silica Nanoparticles with Transcaucasian Nose-Horned Viper, <Emphasis Type="Italic">Vipera ammodytes transcaucasiana</Emphasis>, Venom on U87MG and SHSY5Y Neuronal Cancer Cells

Highly bioactive compounds of the snake venom make them particular sources for anticancer agent development. They contain very rich peptide-protein structures. Therefore, they are very susceptible to environmental conditions such as temperature, pH, and light. In this study, Vipera ammodytes transcaucasiana venom was encapsulated in PAMAM-G4 dendrimer by sol-gel method in order to prevent degradation of venom contents from the environmental conditions. For this purpose, nanoparticles were prepared by sol-gel methodology and SEM analyses were performed. U87MG and SHSY5Y neuronal cancer cell lines were treated with different concentrations of venom-containing nanoparticles and cytotoxicity was determined by MTT assay. IC₅₀ values of nanoparticles with snake venom were calculated as 37.24 and 44.64 μg/ml for U87MG and SHSY5Y cells, respectively. The IC₅₀ values of nanoparticles with snake venom were calculated as 10.07 and 7.9 μg/ml for U87MG and SHSY5Y cells, respectively. As a result, nanoparticles with V. a. transcaucasiana venom showed remarkably high cytotoxicity. Encapsulation efficiency of nanoparticles with 1 mg/ml snake venom was determined as %67 via BCA? protein analysis. In conclusion, this method is found to be convenient and useful for encapsulating snake venom as well as being suitable for drug delivery systems.     

Particle Size Limit for Concomitant Tuning of Size and Shape of Platinum Nanoparticles

Based on a polyol process, one-step synthetic procedures were investigated for concomitant control of the shape and size of platinum nanoparticles (Pt NPs). Cubic and octahedral/tetrahedral particles of different sizes (5–10 nm) were synthesized using these procedures. Further attempts to control the shape of the NPs below 3–4 nm failed. It was found that 3–4 nm is the particle size limit for Pt NPs above which the particle size and shape can be concomitantly controlled.     

Integrated Devices for Non-Invasive Diagnostics

“Sample-in-answer-out” type integrated diagnostic devices have been widely recognized as the ultimate solution to simplify testing across healthcare systems. Such systems are equipped with advanced fluidic, mechanical, chemical, biological, and electronic components to handle patient samples without any manual steps therefore have the potential to accelerate intervention and improve patient outcomes. In this regard, the combination of integrated devices and non-invasive sampling has gained a substantial interest to further improve the comfort and safety of patients. In this Review, the pioneering developments in integrated diagnostics are covered and their potential in non-invasive sampling is discussed. The key properties of possible sample types are highlighted by addressing their relevance for the clinical practice. Last, the factors affecting the transition of integrated devices from academia to the market are identified by analyzing the technology readiness levels of selected examples and alternative remedies are explored to increase the rate of survival during this transition.     

Simultaneous Determination of Rosiglitazone and Metformin in Pharmaceutical Preparations by LC

In the present study, a novel, fast and simple liquid chromatographic method was developed and validated for the simultaneous determination of rosiglitazone and metformin in pharmaceutical preparations. The separation was achieved on a phenyl column (250 × 4.6 mm i.d., 5 μm) using a mobile phase composed of acetonitrile:10.0 mM phosphate buffer pH 5.5 (70:30, v/v). The flow rate was 1 mL min⁻¹. UV detection was performed at 245 nm and verapamil was used as internal standard. The developed method was validated in terms of stability, specificity, sensitivity, linearity, accuracy, precision and robustness. The limit of quantification was 0.02 μg mL⁻¹ for both drugs. The method developed was successfully applied to the simultaneous determination of rosiglitazone and metformin in pharmaceutical preparations. The results were compared to two methods reported in the literature and no significant difference was found statistically.     

An unexpected enhancement in methanol electro-oxidation on an ensemble of Pt(111) nanofacets: a case of nanoscale single crystal ensemble electrocatalysis

Pt nanoparticles having the same size ( approximately 10 nm) but different shapes (cubic or octahedral/tetrahedral), as determined by transmission electron microscopy, were synthesized via a polyol-based synthetic procedure. Their respective electrocatalytic activities for methanol oxidation were characterized by cyclic voltammetry and chronoamperometry in both sulfuric and perchloric acid electrolytes, which showed clear shape (surface orientation) dependences. Furthermore, the octahedral/tetrahedral Pt nanoparticles displayed an unexpectedly large enhancement in methanol electro-oxidation activity; about 3-fold increase in transient intrinsic activity and 10-fold increase in CO tolerance steady-state activity when compared to commercial Pt black. Gaseous and methanolic CO adsorption on the synthesized nanoparticles were also investigated by surface-enhanced IR absorption spectroscopy in perchloric acid electrolyte, which suggested that the different trends observed might be related to the electronic effects specific to a given ensemble of the nanofacets.     

A novel strategy on the spectrochromatographic analysis of a quaternary mixture by parallel factor analysis model

Poor chromatographic resolution is one of the main challenges in chromatographic analysis. Partially separated chromatographic peaks frequently occur, due to the nature of analytes and the demand for fast analysis using high flow rates and shorter columns. Modeling of chromatographic three-way data using suitable chemometric tools enables determining co-eluted peaks without using additional experimental efforts. In this paper, parallel factor analysis (PARAFAC) was applied to chromatographic data for the quantitative resolution of a quaternary mixture at the co-elution condition of acetaminophen, aspirin, ascorbic acid, and guaifenesin in a spectrochromatogram. The spectrochromatograms of the calibration set, validation set, and real samples were arranged as a three-way array. In the next step, the PARAFAC model was implemented to decompose the spectrochromatographic array into trilinear components, corresponding to spectral, chromatographic, and relative concentration profiles of the analytes. The chromatographic and spectral modes were used for the qualitative analysis of components, whereas the analytes in commercial tablets were quantified from their individual profiles in their concentration mode. This study indicated that the application of the PARAFAC model provided a novel strategy for determining overlapping peaks in a chromatogram to perform the analysis of multicomponent mixtures with reduced runtime and without additional efforts.     

Detection of bacteria using antimicrobial polymer derived via ring-opening metathesis (romp) pathway

There is growing interest in the detection of bacteria in consumables, for example, in the food and water sectors. In this study, the aim was to produce a polymer-based bacteria biosensor via ROMP (ring opening metathesis polymerization). In the first part of the study, block and random copolymers were synthesized, and their biocidal activities were tested on the glass surface. Interdigitated electrode arrays coated with the polymers possessing the highest activity were used to screen the affinity towards different bacterial strains by monitoring impedance variations in real-time. The polymer-coated electrode could detect gram-positive and gram-negative bacteria strains at a concentration of 10⁷ cfu/mL. The results show that ROMP-based polymer offers bacterial detection and can be used in developing biosensor devices for efficiently detecting pathogenic bacteria.     

Supercritical carbon dioxide extraction of Usnea longissima (L.) Ach.: Optimization by Box-Behnken design (BBD)

Usnic acid (UA) was extracted from Usnea longissima (L.) Ach. in supercritical carbon dioxide (SC-CO₂) medium. The selected process parameters were extraction temperature (35–45 °C), amount of co-solvent (0%–5%) and extraction time (5–9 h). These parameters were applied to Box-Behnken design (BBD) belonging to response surface methodology (RSM) to determine optimum process parameters for the highest amount of UA in the extract. g UA/100g lichen, extraction yield % and UA content values were calculated in the range of 0.045–0.317, 2.77–5.4 and 71%–82% in different experimental conditions, respectively. The optimum conditions were predicted as 42 °C, 4.3% (ethanol) and 7.48 h. It was determined that the predicted and experimental values of g UA/100g lichen were compatible, and the suggested model was valid.     

Orange Peel Derived-Nitrogen and Sulfur Co-doped Carbon Dots: a Nano-booster for Enhancing ORR Electrocatalytic Performance of 3D Graphene Networks

Herein, nitrogen, sulfur co-doped carbon dots (N,S−CDs) have been synthesized by a cost-natural fabrication method using waste orange-peel as a natural-carbon-precursor. N,S−CDs have been hydrothermally anchored to the three-dimensional-graphene-networks (3D−GNs) to boost the electrocatalytic activity by a defective surface effect. Due to the synergistic utilization of heteroatoms, and effective mass-transfer and improved transport kinetics resulting from interconnected 3D-architecture, N,S−CDs anchored 3D−GNs (N,S−CDs@3D−GNs) grant superior oxygen-reduction-reaction (ORR) activity. N,S−CDs@3D−GNs exhibit a dominant four-electron pathway (n=3.89) for ORR in alkaline media besides superior methanol tolerance and robust stability. This work opens a door for converting low-value agricultural wastes into value-added materials for utilizing in energy application.