Potent biological activity of newly fabricated silver nanoparticles coated by a carbon shell synthesized by electrical arc

Highly effective AgNPs@C was efficiently synthesized by electrical arc powered by single spark unit which was sufficient to ionize the dielectric media (deionized water) through applying strong electric field between the electrodes (silver and carbon). The AgNPs@C shell was characterized in terms of stability, morphology and phase structure. All characterizations showed that the prepared silver nanoparticles were spherical with average size reached 17 nm coated with carbon shell. The antibacterial effect of the synthesized nanoparticles was tested against Pseudomonas aeruginosa in comparison to Ceftazidime (commonly used antibiotic against P. aeruginosa infections). It was revealed that AgNPs@C shell has superior activity with inhibition zone diameter reached 15 mm and minimum inhibitory concentration reached 2 µg/mL. The observed activity was further confirmed by confocal microscope which showed an increased red region, representing the dead cells, correlated with the presence of AgNPs@C. Moreover, transmission electron microscope studies implied the possible AgNPs@C antibacterial mechanism of action was the nanoparticles adherence to the bacterial membrane causing cell lysis. The molecular studies against fimH (virulence adhesion gene), rmpA (mucoid factor encoding gene), and mrkA (biofilm forming gene) proved the inhibition of their genetic expression. The cytotoxic effect of the synthesized AgNPs@C showed CC50 reached 235.5 μg/mL against normal lung cells (L929 cell line).

Nickel vanadate nitrogen-doped carbon nanocomposites for high-performance supercapacitor electrode

A nickel-vanadium-based bimetallic precursor was produced using the polymerization process by urea-formaldehyde copolymers. The precursor was then calcined at 800 °C in an argon ambiance to form a Ni3V2O8-NC magnetic nanocomposite. Powerful techniques were used to study the physical characteristics and chemical composition of the fabricated Ni3V2O8-NC electrode. PXRD, Raman, and FTIR analyses proved that the crystal structure of Ni3V2O8-NC included N-doped graphitic carbon. FESEM and TEM analyses imaging showed the distribution of the Ni3V2O8 nanoparticles on the layered graphitic carbon structure. TEM images showed the prepared sample has a particle size of around 10-15 nm with an enhanced active site area of 146 m2/g, as demonstrated by BET analysis. Ni3V2O8-NC nanocomposite exhibits magnetic behaviors and a magnetization saturation value of 35.99 emu/g. The electrochemical (EC) studies of the synthesized Ni3V2O8-NC electrode proceeded in an EC workstation of three-electrode. In a 5 M potassium hydroxide as an electrolyte, the cyclic voltmeter exhibited an enhanced capacitance (CS) of 915 F/g at 50 mV/s. Galvanic charge-discharge (GCD) study also exhibited a superior capacitive improvement of 1045 F/g at a current density (It) of 10 A/g. Moreover, the fabricated Ni3V2O8-NC nanocomposite displays a good power density (Pt) of 356.67 W/kg, improved ion accessibility, and substantial charge storage. At the high energy density (Et) of 67.34 W h/kg, the obtained Pt was 285.17 W/kg. The enhanced GCD rate, cycle stability, and Et of the Ni3V2O8-NC magnetic nanocomposite nominate the sample as an excellent supercapacitor electrode. This study paves the way for developing effective, efficient, affordable, and ecologically friendly electrode materials.

Nanoparticles as Drug Delivery Systems: A Review of the Implication of Nanoparticles' Physicochemical Properties on Responses in Biological Systems

In the last four decades, nanotechnology has gained momentum with no sign of slowing down. The application of inventions or products from nanotechnology has revolutionised all aspects of everyday life ranging from medical applications to its impact on the food industry. Nanoparticles have made it possible to significantly extend the shelf lives of food product, improve intracellular delivery of hydrophobic drugs and improve the efficacy of specific therapeutics such as anticancer agents. As a consequence, nanotechnology has not only impacted the global standard of living but has also impacted the global economy. In this review, the characteristics of nanoparticles that confers them with suitable and potentially toxic biological effects, as well as their applications in different biological fields and nanoparticle-based drugs and delivery systems in biomedicine including nano-based drugs currently approved by the U.S. Food and Drug Administration (FDA) are discussed. The possible consequence of continuous exposure to nanoparticles due to the increased use of nanotechnology and possible solution is also highlighted.

Pt(IV) pro-drugs with an axial HDAC inhibitor demonstrate multimodal mechanisms involving DNA damage and apoptosis independent of cisplatin resistance in A2780/A2780cis cells

Epigenetic agents such as histone deacetylase (HDAC) inhibitors are widely investigated for use in combined anticancer therapy and the co-administration of Pt drugs with HDAC inhibitors has shown promise for the treatment of resistant cancers. Coordination of an HDAC inhibitor to an axial position of a Pt(IV) derivative of cisplatin allows the combination of the epigenetic drug and the Pt chemotherapeutic into a single molecule. In this work we carry out mechanistic studies on the known Pt(IV) complex cis,cis,trans-[Pt(NH₃)₂Cl₂(PBA)₂] (B) with the HDAC inhibitor 4-phenylbutyrate (PBA) and its derivatives cis,cis,trans-[Pt(NH₃)₂Cl₂(PBA)(OH)] (A), cis,cis,trans-[Pt(NH₃)₂Cl₂(PBA)(Bz)] (C), and cis,cis,trans-[Pt(NH₃)₂Cl₂(PBA)(Suc)] (D) (Bz = benzoate, Suc = succinate). The comparison of the cytotoxicity, effect on HDAC activity, reactive oxygen species (ROS) generation, γ-H2AX (histone 2A-family member X) foci generation and induction of apoptosis in cisplatin-sensitive and cisplatin-resistant ovarian cancer cells shows that A - C exhibit multimodal mechanisms involving DNA damage and apoptosis independent of cisplatin resistance.

Antitumor platinum(IV) derivatives of carboplatin and the histone deacetylase inhibitor 4-phenylbutyric acid

Five new platinum(IV) derivatives of carboplatin each incorporating the histone deacetylase inhibitor 4-phenylbutyrate in axial position were synthesized and characterized by ¹H and ¹⁹⁵Pt NMR spectroscopy, electrospray ionization mass spectrometry and elemental analysis, namely cis,trans-[Pt(CBDCA)(NH₃)₂(PBA)(OH)] (1), cis,trans-[Pt(CBDCA)(NH₃)₂(PBA)₂] (2), cis,trans-[Pt(CBDCA)(NH₃)₂(PBA)(bz)] (3), cis,trans-[Pt(CBDCA)(NH₃)₂(PBA)(suc)] (4) and cis,trans-[Pt(CBDCA)(NH₃)₂)(PBA)(ac)] (5) (PBA=4-phenylbutyrate, CBDCA=1,1-cyclobutane dicarboxylate, bz=benzoate, suc=succinate and ac=acetate). The reduction behavior in the presence of ascorbic acid was studied by high performance liquid chromatography. The cytotoxicity against a panel of human tumor cell lines, histone deacetylase (HDAC) inhibitory activity, cellular accumulation and the ability to induce apoptosis were evaluated. The most effective complex, compound 3, was found to be up to ten times more effective than carboplatin and to decrease cellular basal HDAC activity by approximately 18% in A431 human cervical cancer cells.