Kappa-carrageenan and sodium alginate-based pH-responsive hydrogels for controlled release of methotrexate.

Despite remarkable progress in medical sciences, modern man is still fighting the battle against cancer. In 2022, only in the USA, 640 000 deaths and 2 370 000 patients were reported because of cancer. Chemotherapy is the most widely used for cancer treatments. However, chemotherapeutics have severe physicochemical side effects. Therefore, we have prepared poly(amididoamine) dendrimeric carrageenan (CG), sodium alginate (SA) and poly(vinyl alcohol) (PVA) hydrogels by using solution casting methodology. The constituents of hydrogels were cross-linked by mutable quantity of 3-aminopropyl(diethoxy)methyl silane (APDMS). Hydrogels were characterized by Fourier transform infrared spectroscopy, thermal gravimetric analysis, scanning electron microscope and atomic force microscopy. Hydrogels exhibited higher swelling volumes in 5-7 pH range. In vitro biodegradation in ribonuclease-A solution and cytocompatibility analysis against DF-1 fibroblasts established their biodegradable and non-toxic nature, which enables them as a suitable carrier for chemotherapeutic compounds. Hence, methotrexate (MTX) as a model drug was loaded on CAP-8 hydrogel and its release was detected by the UV-visible spectrophotometer in phosphate-buffered saline (PBS) solution. In 13.5 h, 81.25% and 77.23% of MTX were released at pH 7.4 (blood pH) and 5.3 (tumour pH) in PBS, respectively. MTX was released by super case II mechanism and best fitted to zero-order and Korsmeyer-Peppas model. The synthesized APDMS cross-linked CG/SA/PVA dendrimeric hydrogels could be an efficient model platform for the effective delivery of MTX in cancer treatments.

Alumina supported copper oxide nanoparticles (CuO/Al2O3) as high-performance electrocatalysts for hydrazine oxidation reaction.

Direct hydrazine liquid fuel cell (DHFC) is perceived as effectual energy generating mean owing to high conversion efficiency and energy density. However, the development of well-designed, cost effective and high performance electrocatalysts is the paramount to establish DHFCs as efficient energy generating technology. Herein, gamma alumina supported copper oxide nanocatalysts (CuO/Al2O3) are synthesized via impregnation method and investigated for their electrocatalytic potential towards hydrazine oxidation reaction. CuO with different weight percentages i.e., 4%, 8%, 12%, 16% and 20% are impregnated on gamma alumina support. X-ray diffraction analysis revealed the cubic crystal structure and nanosized particles of the prepared metal oxides. Transmission electron microscopy also referred to the cubic morphology and nanoparticle formation. Electrochemical oxidation potential of the CuO/Al2O3 nanoparticles is explored via cyclic voltammetry as the analytical tool. Optimization of conditions and electrocatalytic studies shown that 16% CuO/Al2O3 presented the best electronic properties towards N2H2 oxidation reaction. BET analysis ascertained the high surface area (131.2546 m2 g1) and large pore diameter (0.279605 cm³ g-1) for 16% CuO/Al2O3. Nanoparticle formation, high porosity and enlarged surface area of the proposed catalysts resulted in significant oxidation current output (600 µA), high current density (8.2 mA cm-2) and low charge transfer resistance (3.7 kΩ). Electrooxidation of hydrazine on such an affordable and novel electrocatalyst opens a gateway to further explore the metal oxide impregnated alumina materials for different electrochemical applications.

Nickel-doped lanthanum cerate nanomaterials as highly active electrocatalysts.

The efficient oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) catalyst materials are crucial in the energy research domain due to their tunability. Structural modification in perovskites such as lanthanum cerates (LaCeO3) upon doping at A or B sites significantly affects the surface activity and enhances the catalysis efficacy. Herein, B-site nickel-doped lanthanum cerate (LaCe1-xNixO3±Î´) nanopowders were applied as ORR indicators in high-temperature electrochemical impedance spectroscopy for solid-oxide fuel cell (SOFC) tests and in cyclic voltammetric OER investigations in alkaline medium. The integration into SOFC applications, via solid-state EIS in a co-pressed three-layered cell with LCNiO as cathode, is investigated in an oxygen-methane environment and reveals augmented conductivity with temperatures of 700-850°C. The higher electrokinetic parameters-including diffusion coefficients, Do heterogeneous rate constant, ko, and peak current density for OER in KOH-methanol at a LCNiO-9-modified glassy carbon electrode-serve as robust gauges of catalytic performance. CV indicators and EIS conductivities of LaCe1-xNixO3±Î´ nanomaterials indicate promising potencies for electrocatalytic energy applications.

Sol-Gel Synthesized High Entropy Metal Oxides as High-Performance Catalysts for Electrochemical Water Oxidation.

Hexanary high-entropy oxides (HEOs) were synthesized through the mechanochemical sol-gel method for electrocatalytic water oxidation reaction (WOR). As-synthesized catalysts were subjected to characterization, including X-ray diffraction (XRD), Fourier transforms infrared (FTIR) analysis, and scanning electron microscopy (SEM). All the oxide systems exhibited sharp diffraction peaks in XRD patterns indicating the defined crystal structure. Strong absorption between 400-700 cm-1 in FTIR indicated the formation of metal-oxide bonds in all HEO systems. WOR was investigated via cyclic voltammetry using HEOs as electrode platforms, 1M KOH as the basic medium, and 1M methanol (CH3OH) as the facilitator. Voltammetric profiles for both equiatomic (EHEOs) and non-equiatomic (NEHEOs) were investigated, and NEHEOs exhibited the maximum current output for WOR. Moreover, methanol addition improved the current profiles, thus leading to the electrode utility in direct methanol fuel cells as a sequential increase in methanol concentration from 1M to 2M enhanced the OER current density from 61.4 to 94.3 mA cm-2 using NEHEO. The NEHEOs comprising a greater percentage of Al, ([Al0.35(Mg, Fe, Cu, Ni, Co)0.65]3O4) displayed high WOR catalytic performance with the maximum diffusion coefficient, D° (10.90 cm2 s-1) and heterogeneous rate constant, k° (7.98 cm s-1) values. These primary findings from the EC processes for WOR provide the foundation for their applications in high-energy devices. Conclusively, HEOs are proven as novel and efficient catalytic platforms for electrochemical water oxidation.

MXene/Ag2CrO4 Nanocomposite as Supercapacitors Electrode.

MXene/Ag2CrO4 nanocomposite was synthesized effectively by means of superficial low-cost co-precipitation technique in order to inspect its capacitive storage potential for supercapacitors. MXene was etched from MAX powder and Ag2CrO4 spinel was synthesized by an easy sol-gel scheme. X-Ray diffraction (XRD) revealed an addition in inter-planar spacing from 4.7 Å to 6.2 Å while Ag2CrO4 nanoparticles diffused in form of clusters over MXene layers that had been explored by scanning electron microscopy (SEM). Energy dispersive X-Ray (EDX) demonstrated the elemental analysis. Raman spectroscopy opens the gap between bonding structure of as-synthesized nanocomposite. From photoluminence (PL) spectra the energy band gap value 3.86 eV was estimated. Electrode properties were characterized by applying electrochemical observations such as cyclic voltammetry along with electrochemical impedance spectroscopy (EIS) for understanding redox mechanism and electron transfer rate constant Kapp. Additionally, this novel work will be an assessment to analyze the capacitive behavior of electrode in different electrolytes such as in acidic of 0.1 M H2SO4 has specific capacitance Csp = 525 F/g at 10 mVs-1 and much low value in basic of 1 M KOH electrolyte. This paper reflects the novel synthesis and applications of MXene/Ag2CrO4 nanocomposite electrode fabrication in energy storage devices such as supercapacitors.

Engineering electroactive and biocompatible tetra(aniline)-based terpolymers with tunable intrinsic antioxidant properties in vivo.

Under different pathological conditions, high levels of reactive oxygen species (ROS) cause substantial damage to multiple organs. To counter these ROS levels in multiple organs, we have engineered highly potent novel terpolymers. We found that combination of FDA-approved polyethylene glycol, fumaric acid moieties and electroactive tetra(aniline) by varying the content of tetra(aniline) results into a novel drug composition with biologically active and tunable intrinsic antioxidant properties. To test the intrinsic antioxidative properties of these novel terpolymers, we used alloxan to induce diabetes in rats where ROS generation is known to be higher. The systemic administration of terpolymers to the diabetic rats showed strong electroactive antioxidant behavior which not only normalized ROS levels, but also improved the levels of enzymatic antioxidants including superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH). As a proof-of-principle, we here show TANI based novel drug composition of terpolymers with tunable intrinsic antioxidant properties in multiple organs.

Biferrocenyl Schiff bases as efficient corrosion inhibitors for an aluminium alloy in HCl solution: a combined experimental and theoretical study.

The corrosion inhibitive capabilities of some ferrocene-based Schiff bases on aluminium alloy AA2219-T6 in acidic medium were investigated using Tafel polarization, electrochemical impedance spectroscopy (EIS), weight loss measurement, FT-IR spectroscopy and scanning electron microscopic (SEM) techniques. The influence of molecular configuration on the corrosion inhibition behavior has been explored by quantum chemical calculation. Ferrocenyl Schiff bases 4,4'-((((ethane-1,2-diylbis(oxy))bis(4,1-phenylene))bis(methaneylylidene))bis(azaneylylidene))bisferrocene (Fcua), 4,4'-((((ethane-1,2-diylbis(oxy))bis(2-methoxy-1,4-phenylene))bis(methaneylylidene))bis(azaneylylidene))bisferrocene (Fcub) and 4,4'-((((ethane-1,2-diylbis(oxy))bis(2-ethoxy-1,4-phenylene))bis(methaneylylidene))bis(azaneylylidene))bisferrocene (Fcuc) have been synthesized and characterized by FT-IR, 1H and 13C NMR spectroscopic studies. These compounds showed a substantial corrosion inhibition against aluminium alloy in 0.1 M of HCl at 298 K. Fcub and Fcuc showed better anticorrosion efficiency as compared with Fcua due to the electron donating methoxy and ethoxy group substitutions, respectively. Polarization curves also indicated that the studied biferrocenyl Schiff bases were mixed type anticorrosive materials. The inhibition of the aluminium alloy surface by biferrocenyl Schiff bases was evidenced through scanning electron microscopy (SEM) studies. Semi-empirical quantum mechanical studies revealed a correlation between corrosion inhibition efficiency and structural functionalities.

CoPtx/γ-Al2O3 bimetallic nanoalloys as promising catalysts for hydrazine electrooxidation.

Stable bimetallic catalysts composed of CoPtx/γ-Al2O3 (x = Pt/Co molar ratio) were synthesized by wet impregnation method followed by calcination and the H2 reduction. The powders were characterized using XRD, AAS, BET, SEM, EDX, TPR, and TPO techniques. The prepared catalysts were drop casted on the glassy carbon electrode (GCE) and catalytic performance was examined for hydrazine electrooxidation in alkaline medium via cyclic voltammetry (CV). All the compositions in CoPtx/γ-Al2O3 series showed high responses towards hydrazine electrooxidation, however; high activity of CoPt0.034/γ-Al2O3 catalyst inferred it as a best material with an anodic peak current (iP) response of 200 µA at 0.86 V. The prominent electrochemical (EC) responses for this composition are attributed to better accessible surface area resulting in a fast electron transfer. The CoPtx/γ-Al2O3 catalysts are reported as the robust and superior prospective materials for extensive electroanalytical and catalytic studies.

Radical scavenging propensity of Cu2+, Fe3+ complexes of flavonoids and in-vivo radical scavenging by Fe3+-primuletin.

Cu2+ and Fe3+ complexes of three flavonoids (morin or mo, quercetin or quer and primuletin or prim) were synthesized with the objective of improving antioxidant capacities of flavonoids. The radical scavenging activities of pure flavonoids and their metal complexes were assayed to monitor their tendencies towards sequestering of radicals at physiological conditions. The scavenger potencies of metal-flavonoid complexes were significantly higher than those of the parent flavonoids. Further, influence of the solvent polarity on the radical capturing by flavonoids and their metal complexes was in favor for the polar solvent. Fe3+-prim displayed its radical scavenging ability via up gradation of CAT and SOD activities in in-vivo antioxidant assays.

ß-Cyclodextrin assisted solubilization of Cu and Cr complexes of flavonoids in aqueous medium: a DNA-interaction study.

Cu and Cr complexes of three flavonoids (morin, quercetin and 6-hydroxyflavone) were synthesized and included in beta-cyclodextrin (ßCD) with the objective of improving their pharmacokinetic profiles. Then binding with ds.DNA was studied to monitor their interactive tendencies at physiological conditions. The binding constants and other thermodynamic data from UV-vis spectroscopy and cyclic voltammetry revealed Cr-flavonoid-ßCD to interact with ds.DNA at pH-7.4 through electrostatic mode of binding while Cu-flavonoid-ßCD can intercalate into DNA. The strong binding propensity of Cu-flavonoid-ßCD with ds.DNA encourages their application as anticancerous agent.

Flavonoid-DNA binding studies and thermodynamic parameters.

Interactional studies of new flavonoid derivatives (Fl) with chicken blood ds.DNA were investigated spectrophotometrically in DMSO-H2O (9:1 v/v) at various temperatures. Spectral parameters suggest considerable binding between the flavonoid derivatives studied and ds.DNA. The binding constant values lie in the enhanced-binding range. Thermodynamic parameters obtained from UV studies also point to strong spontaneous binding of Fl with ds.DNA. Viscometric studies complimented the UV results where a small linear increase in relative viscosity of the DNA solution was observed with added optimal flavonoid concentration. An overall mixed mode of interaction (intercalative plus groove binding) is proposed between DNA and flavonoids. Conclusively, investigated flavonoid derivatives are found to be strong DNA binders and seem to be promising drug candidates like their natural analogues.

Spectrophotometric analysis of flavonoid-DNA binding interactions at physiological conditions.

Mode of interactions of three flavonoids [morin (M), quercetin (Q), and rutin (R)] with chicken blood ds.DNA (ck.DNA) has been investigated spectrophotometrically at different temperatures including body temperature (310 K) and at two physiological pH values, i.e. 7.4 (human blood pH) and 4.7 (stomach pH). The binding constants, K(f), evaluated using Benesi-Hildebrand equation showed that the flavonoids bind effectively through intercalation at both pH values and body temperature. Quercetin, somehow, showed greater binding capabilities with DNA. The free energies of flavonoid-DNA complexes indicated the spontaneity of their binding. The order of binding constants of three flavonoids at both pH values were found to be K(f(Q)) > K(f(R)) > K(f(M)) and at 310 K.

Electrochemical and spectroscopic investigations of protonated ferrocene-DNA intercalation.

The interaction of protonated ferrocene (PF) with chicken blood DNA (CB-DNA) has been investigated in vitro by cyclic voltammetry (CV) and UV-Vis spectroscopy as well as viscosity measurements under stomach pH and body temperature. The peak potentials shift in CV, hyperchromism in UV absorption titration, an increase in the viscosity of DNA and the results of the effect of ionic strength on the binding constant strongly support the intercalation of PF into the DNA double helix. The diffusion coefficients of PF in the presence and absence of DNA were 9.54 x 10(-11) and 1.34 x 10(-10) m2/s, respectively. The binding constant of the PF-DNA complex and the number of binding sites on a DNA molecule were calculated as being 3.07 x 10(2) M(-1) and 2.96, with the help of the Scatchard equation. An expression by Carter et al. was used for determining the binding site size (0.17 bp). The binding constant was also determined by UV absorption titration.

Charge transfer complexes of picolines with sigma- and pi-acceptors.

In the present study CT complexes of 2-, 3- and 4-Picolines with (DDQ) 2, 3-dichloro-5, 6-dicyano parabenzoquinone (pi-acceptor) and (I2) Iodine (sigma-acceptor) have been investigated spectrophotometrically in three different solvents (CCl4, CHCl3 and CH2Cl2) at six different temperatures. The formation constants of the CT complexes were determined by the Benesi-Hildebrand equation. The thermodynamic parameters were calculated by Van(')t Hoff equation. The DeltaH degrees , DeltaG degrees and DeltaS degrees values are all negative implying that the formation of studied complexes is exothermic in nature.