Synthesis, Characterisation and pH-Responsive Controlled Release Studies of 5- Fluorouracil Drug from Silica CoatedLao.1Sro.3Mn03Magnetic Nanoparticles

One of the drawbacks of some drug delivery system (DDS) is their inability to release their payloads after reaching the desired site of action. Hence, many DDSs are being evaluated that are able to release their payloads upon action of an external stimulus. La0.7SrO.JMn03 MNPs were synthesized by solution combustion synthesis and the optimised MNPs were coated with silica. The synthesized MNPs were characterised by X-ray diffraction (XRD), thermogravimetry-differential thermal analysis (TG-DTA), field emission scanning electron microscope (FE-SEM), energy dispersive absorption spectroscopy (EDAX), fourier transform infra-red spectroscopy (FTIR), vibrating scanning magnetometer (VSM), zeta potential measurements and ultraviolet-visible spectroscopy (UV-Vis). The anticancer drug delivery capability of La0.7SrO.JMn03 MNPs was carried out. Silica coatings with were utilised for the loading of 5-Fluoro uracil (5-FU)- a well-known anti-cancer drug. The silica surface was functionalised with amino propyl (LSMO-Si02-NH2) to achieve charge reversal of the designed system from negative to positive as pH varied from 7.4 to 5 which was used for the effective release of the cargo at endosomal pH 5. The high 5-FU drug loading and its pH-sensitive release from LSMO-Si02-NH2 suggest that it is a promising material for targeted drug delivery application

Structural, morphological and magnetic properties of La1−xNayMnO3 (y ≤ x) nanoparticles produced by the solution combustion method

The rapid solution combustion synthesis and characterization of sodium (Na)-substituted LaMnO3 phases at relatively low temperature using polyvinyl alcohol (PVA) as fuel were reported. The thermal decomposition process investigated by means of differential and thermal gravimetric analysis (TG–DTA) showed that the use of PVA as a fuel was satisfactory in the synthesis of the perovskite manganite compound. Structural study using X-ray diffraction showed that all the samples were single phasic without any detectable impurities within the measurement range. Also, the Na-substituted compounds crystallize with rhombohedral symmetry (space group R-3c, no. 167) with La0.80Na0.15MnO3 manganite sample giving the highest crystallinity. Microstructural features observed by field-emission scanning electron microscopy demonstrated that most of the grains were nearly spherical in shape with fairly uniform distribution and all the observed particles connect with each other. Energy-dispersive X-ray analyses confirm the homogeneity of the samples. Increase in magnetic moment was observed with the increase in sodium doping. Room-temperature vibrating sample magnetometer measurements showed that the samples were ferromagnetic with compositions y = 0.10, 0.15 and 0.20 showing relatively high magnetic moments of 33, 34 and 36 emu g−1, respectively

Silica coated LSMO magnetic nanoparticles for the pH-Responsive delivery of 5-Fluorouracil anticancer drug

The design of a drug delivery system capable of a pH-responsive controlled 5-fluorouracil anticancer drug release to cancer sites is one of the important options to reduce the well documented side effects of this drug. La0.7Sr0.3MnO3 (LSMO) magnetic nanoparticles (MNPs) were synthesized by solution combustion synthesis and the optimized MNPs were coated with silica. X-ray diffraction patterns reveal that the crystal structure is a single perovskite phase which was unchanged after silica coating. Silica coating on LSMO was found to reduce the nanoparticle crystallite and magnetic properties. The silica surface of LSMO MNPs was functionalized to confer a pH-dependent switchable surface and was used to demonstrate the pH-responsive controlled release of 5-FU anticancer drug which was significantly higher than the 5-FU released from silica coated LSMO MNPs that were not functionalized. The in-vitro release studies show that only 11.36% of 5-FU was released at pH 7.4 (mimic of the physiological environment) and 37.20% at pH 5.0 (mimic of the intracellular organelles of cancer cells). The pH-responsive release of this functionalized silica coated LSMO MNPs suggest that it could be used in the controlled release of 5-FU anticancer drug at tumor sites

Solutions of the Klein-Gordon Equation with Equal Scalar and Vector Harmonic Oscillator plus Inverse Quadratic Potential

The solutions of the Klein-Gordon equation with equal scalar and vector harmonic oscillator plus inverse quadratic potential for S-waves have been presented using the Nikiforov-Uvarov method. The bound state energy eigenvalues and the corresponding un-normalized eigenfunctions are obtained in terms of the Laguerre polynomials

Magneto-structural properties of Ni–Zn nanoferrites synthesized by the low-temperature auto-combustion method

Using nickel, zinc and ferric nitrates, and glycine in a fuel-rich composition, Ni1–xZnxFe2O4 nanoparticles were prepared by a simple low-temperature auto-combustion method without further sintering at high temperatures. The auto-combusted powders obtained were characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy, energy-dispersive X-ray (EDAX) analysis and vibrating scanning magnetometer measurements. XRD confirms the formation of pure nanocrystalline spinel phases with an average diameter of about 55 nm. Raman spectra show tetrahedral and octahedral sites in the structure of Ni1–xZnxFe2O4 and also imply the doping of Zn2+ and displacement of Fe3+ ions from the tetrahedral site. EDAX showed that the samples were close to the nominal compositions. The magnetic measurement shows that the saturation magnetization and remanence magnetization decreases with the increase in the zinc content

Experimental and Theoretical Studies of (E)-N'-1-(4- propylbenzylidene)nicotinohydrazide as Corrosion Inhibitor of Mild Steel in 1 M HC

The efficiency of a novel Schiff base namely (E)-N'-1-(4-propylbenzylidene)nicotinohydrazide (PBNH) was investigated as corrosion inhibitor of mild steel (MS) in 1M HCl using weight loss technique at 303 and 313 K. It was established that corrosion rate of mild steel increases with increase in temperature and concentration of HCl. Results showed that PBNH considerably inhibited the corrosion of mild steel in a 1 M HCl solution and inhibition efficiency is about 70% at 4 × 10–4 M PBNH at both temperatures. The inhibi� tion efficiency of PBNH increased with an increase in concentration and temperature. The adsorption model obeys the Langmuir adsorption isotherm and the kinetic–thermodynamic model and the value of free energy of adsorption, indicated that the adsorption of PBNH was a spontaneous process and was both an elec� trostatic�adsorption (physisorption) and adsorption on the basis of donor�acceptor interactions (chemisorp�tion). Thermodynamic parameters calculated show the spontaneity and endothermic nature of the process and also reveal the favourable affinity of PBNH towards the mild steel surface. Quantum chemical calcula�tions based on PM3 method was performed on PBNH and calculated parameters gave useful information to explain the interaction between the surface of metal and PBNH

PHYSICO-CHEMICAL AND MICROBIAL ASSESSMENT OF DIFFERENT WATER SOURCES IN OTA, OGUN STATE, NIGERIA

Pollution of water bodies is one of the areas of major concern to en vironmentalists and requires continuous assess ment. This necessitated the evaluation of the physical, chemical an d microbiological quality of water from the primary sources of supply in different locations of Ota using standard methods. Results of the values of the surface and potable water in the study area showed that turbidity(0.19 to 11.6 NTU), conductivity (36.5 to 396 µs/cm), salinity (10 to 80 mg/L), alkalinity (0 to 64 mg/L), nitrate (0.20 to 4.60 mg/L), total hardness (5.0 to 80.0 m g/L), total solid (4000 to 7000 mg/L) total suspended solids (3967 to 6978 mg/L) total dissolved solids (17.9 to 198 mg/L), dissolved oxygen (4.50 to 9.60 mg/L), biochemical oxygen demand (ND to 4.67 mg/L), MPN c ount (2 to 1600 MPN/100 ml) and the faecal coliform counts ranged between ND to 2.5×104. The Physico chemic al parameters of most of the samples analysed were within the limits set by both National and International standa rd regulatory bodies for drinking and domestic waters (SON, 2007; WHO, 2011). Overall, the potable water sources are suitable for drinking, but the faecal contamination in Iju River makes it unfit for drinking

Silica Functionalized Magnesium Ferrite Nanocomposites for Potential Biomedical Applications: Preparation, Characterization and Enhanced Colloidal Stability Studies

Magnetic nanocomposite material composed of silica coated MgFe2O4 for potential biomedical applications were synthesized by a two-step chemical method including solution combustion synthesis, followed by silica coatings of the ferrite nanoparticles. The effects of silica coatings on the structural, morphological and magnetic properties were comprehensively investigated using powder X-ray diffraction (XRD), Field Emission Scanning Electron Microscope (FESEM), energy dispersive absorption x-ray (EDAX), Fourier Transform Infrared spectroscopy (FTIR), thermogravimetric analysis and differential thermal analysis (TG–DTA) and vibrating sample magnetometer (VSM). The colloidal behaviour of coated MNPs in physiological saline medium like water or phosphate buffer saline (PBS) was also studied by zeta potential measurements. The XRD patterns indicate that the crystalline structure is single cubic spinel phase and the spinel structure is retained after silica coating. Also, after silica coating, the crystallite size (from Scherrer formula) decreases from 53 to 47 nm. The magnetic results show that MgFe2O4 MNPs (bare and silica coated) is ferrimagnetic at room temperature. Zeta potential studies revealed that there is enhanced colloidal stability of MgFe2O4 MNPs after silica coating in aqueous media which is an applicable potential in biomedical application

Tandem Synthesis of some Low and High Indexed Monometallic Nanoparticles in Polyols, Poly(Vinylpyrrolidone), Trisodium Citrate and Dodecanethiol Matrices

Sequential synthesis of some noble metal nanoparticles was successfully carried out by polyol/borohydride or hydrazine reduction in the presence of poly(vinylpyrrolidone), trisodium citrate and dodecanethiol in non-aqueous and aqueous solutions with concomitant precipitation of some high index faceted nanoparticles. The polyols afforded Pt NPs as small as 3.5 nm in diameter, which gradually (over a period of months) self-assembled into nanorods that were 5-6 nm in width and 20-30 nm in length. The formation of low indexed Pt NPs species occurred only at moderate temperature, but Pd high indexed face-centered cubic structures formed at 160 °C, while Co formed high indexed nanodiscs at 190 °C with an average diameter of 11.23 nm. The process could be monitored by UV absorption spectrophotometer, powder x-ray diffractometer and transmission electron microscopy (TEM). The polyol was indeed multifunctional: it reduced M+ (Co2+, Ni2+, Ru3+, Pd2+, Pt4+), stabilized the obtained M0 species and served as a template for the tandem formation of monometallic NPs of different morphology

Antimicrobial and Thermal Properties of Coating Systems Modified with ZnO Nanoparticle and its Hybrid Forms: (A Review)

This review examines the unparalleled chemical and physical properties of ZnO nanoparticles and its hybrid forms. The influence of these multifunctional materials within the polymeric matrix of organic coatings was discussed. The scanning electron microscope is seen to provide relevant information about the dispersion of the hybrid and composite coating systems. This review provides concise information about the antimicrobial and thermal stability of composites