Biocompatible tumor micro-environment responsive CS-g-PNIPAAm co-polymeric nanoparticles for targeted Oxaliplatin delivery

The objective of the research study was to develop and characterize a biodegradable, thermo and pH dual responsive Oxaliplatin-loaded chitosan-graft-poly-N-isopropylacrylamide (CS-g-PNIPAAm) co-polymeric nanoparticles as a tumor-targeting drug delivery system. CS-g-PNIPAAm co-polymers were synthesized, characterized and optimized its thermo and pH responsive properties for tumor microenvironment conditions. Optimized co-polymer could be efficiently loaded with Oxaliplatin in nanoparticle form, evaluated for their morphology (TEM), particle size, zeta potential, loading efficiency and drug content. In vitro drug release study at tumor microenvironment and physiological pH and temperature conditions. The in vitro drug release was optimal at above lower critical solution temperature (LCST) and tumor microenvironment pH when compared to physiological pH & temperature. MTT assay and fluorescence microscopic study showed that drug release and cell uptake was significantly enhanced in tumor microenvironment. In conclusion, the obtained nanoparticles appeared to be of great promise in tumor targeted drug delivery of oxaliplatin.     

Preparation of ethyleneamine functionalized crosslinked poly(acrylonitrile-ethylene glycol-dimethacrylate) chelating resins for adsorption of lead ions

Removal of lead ions was investigated by ethylenediamine, triethylenetetramine and tetraethylenepentamine functionalized polymeric adsorbent. Macroporous acrylonitrile-ethylene glycol-dimethacrylate copolymer beads were synthesized by suspension polymerization as already reported.^[17] The adsorbent was prepared by amination of copolymer synthesized from acrylonitrile-ethylene glycol-dimethacrylate. The adsorption study for removal of lead ions using functionalized poly(AN-EGDMA) copolymer as an adsorbent was carried out at room temperature at various solution concentrations of 0.483–2.4154 mmol/l at pH 4.6. Functionalized polymers were studied by Fourier transform infrared spectroscopy (FTIR). Scanning electron microscope-X-ray energy dispersive spectrometer (SEM-EDAX) was utilized to study an increase in nitrogen content of functionalized polymers.     

Synthesis, characterization, and assembly of beta-In2S3 nanoparticles

Semiconductor nanoparticles of Indium Sulphide were synthesized by a hydrothermal method using InCl3 and Na2S. Powder X-ray Diffraction analysis confirmed that the product obtained was nanocrystals of single-phase beta-In2S3. The crystallite size distribution was obtained from the diffraction profile and the average size was approximately 5 nm. The compositional analyses performed on the as-prepared powder showed that the material was devoid of any impurity with an In:S ratio very close to 2:3. A colloid of very fine In2S3 particles was obtained from the as-prepared powder by suspending them in acetonitrile. The optical absorption of this colloid showed evidence of strong quantum confinement of excitons and as a result the particles yielded intense photoluminescence in the violet-blue region. These colloidal particles were then electrophoretically driven on to a transparent conducting substrate to assemble into a nanostructure. A Grazing Incidence X-ray Diffraction analysis of the deposited layer revealed that the preferred orientation noticed in the native powder was removed in the deposit. The surface morphology of the deposit studied using SEM and AFM displayed an inherent ordering behaviour in the clusters organized into a two-dimensional film. The locus of the cluster lines tend to form closed circles, at the nanoscopic as well as microscopic scales, indicative of certain strong neighborhood correlations. Such structures may be expected to exhibit novel correlated properties also.     

Synthesis of Lead Zirconate Titanate Stannate Antiferroelectric Thick Films by Sol-Gel Processing

The effects of different sintering procedures on the preparation of antiferroelectric thick films and the structure–property relations in these films were studied. An acetic acid-based sol–gel processing with multistep annealing and suitable lead oxide overcoat layers was developed to fabricate both niobium-doped and lanthanum-doped lead zirconate titanate stannate antiferroelectric thick films. The 5-μm-thick Pb_0.99Nb_0.02(Zr_0.85Sn_0.13Ti_0.02)_0.98O₃ films demonstrate typical square hysteresis loops with a maximum polarization of 40 μC/cm², zero remanent polarization, an antiferroelectric-to-ferroelectric phase transition field of 153 kV/cm, and a ferroelectric-to-antiferroelectric phase transition field of 97 kV/cm. The dielectric constant and dielectric loss are 283 and 1.7%, respectively. The 5-μm-thick Pb_0.97La_0.02(Zr_0.65Sn_0.31Ti_0.04)O₃ films display typical slanted hysteresis loops with very small hysteresis, a maximum polarization of 35.0 μC/cm², and zero remanent polarization. The dielectric constant and dielectric loss are 434 and 2.0%, respectively.     

Vermicompost extracts influence growth,mineral nutrients,phytonutrients and antioxidant activity in pak choi (Brassica rapa cv. Bonsai,Chinensis group) grown under vermicompost and chemical fertiliser

BACKGROUND: Multiple studies have been reported on the effect of compost tea on suppression of certain plant diseases. However, relatively little work has been done to investigate the effect of vermicompost tea on yield and nutritional quality of vegetable crops. In this study, experiments were conducted to determine the effect of extraction method on vermicompost tea quality and subsequent effects on growth, mineral nutrients, phytonutrients and antioxidant activity of pak choi plants grown under organic (vermicompost) and synthetic (Osmocote) fertilisation. Three vermicompost teas obtained by different extraction methods, namely non‐aerated vermicompost tea (NCT), aerated vermicompost tea (ACT) and aerated vermicompost tea augmented with microbial enhancer (ACTME), were applied to the plants. Aerated water served as control. RESULTS: Mineral nutrients were significantly higher in ACTME compared with other teas, but total microbial population and activity did not differ with extraction method. All vermicompost teas similarly enhanced plant production, mineral nutrients and total carotenoids, and this effect was most prominent under organic fertilisation. Antioxidant activity and total phenolics were higher under organic compared with synthetic fertilisation. Vermicompost teas generally decreased phenolics under organic fertilisation and increased them under synthetic fertilisation compared with the control. CONCLUSION: The effect of vermicompost tea on crop growth is largely attributable to mineral nutrient, particularly N, uptake by plants. Non‐significant differences among extraction methods on plant response within fertiliser regimes suggest that aeration and additives are not necessary for growth promotion and nutrient quality under the conditions reported here. Copyright © 2009 Society of Chemical Industry     

Photovoltaic properties of nanocrystalline CdS films deposited by SILAR and CBD techniques—a comparative study

CdS films were fabricated using Successive Ionic Layer Adsorption and Reaction (SILAR) technique from starting solutions having S:Cd ratio 1:1, 3:1, 5:1 and 7:1 and their structural, surface morphological and optical properties were investigated and compared with that of their chemical bath deposited counterparts. The X-ray diffraction profiles showed that the films have cubic crystal structure with preferential orientation along the (111) plane and the intensity of the (111) plane increases for both the techniques as the S:Cd ratio increases. The energy dispersive X-ray analysis revealed that for SILAR deposited films, the S/Cd ratio in the sample increases from 0.8308 (for S:Cd 1:1) to 1.04 (for S:Cd 7:1) as the molar concentration of sulphur in the starting solution increases. But for CBD films, the S/Cd is only ~0.80 for all concentrations of sulphur in the starting solution. The optical band gap increases with the increase in S:Cd ratio in the starting solution in both the techniques.     

Graphene films with large domain size by a two-step chemical vapor deposition process

The fundamental properties of graphene are making it an attractive material for a wide variety of applications. Various techniques have been developed to produce graphene and recently we discovered the synthesis of large area graphene by chemical vapor deposition (CVD) of methane on Cu foils. We also showed that graphene growth on Cu is a surface-mediated process and the films were polycrystalline with domains having an area of tens of square micrometers. In this paper, we report on the effect of growth parameters such as temperature, and methane flow rate and partial pressure on the growth rate, domain size, and surface coverage of graphene as determined by Raman spectroscopy, and transmission and scanning electron microscopy. On the basis of the results, we developed a two-step CVD process to synthesize graphene films with domains having an area of hundreds of square micrometers. Scanning electron microscopy and Raman spectroscopy clearly show an increase in domain size by changing the growth parameters. Transmission electron microscopy further shows that the domains are crystallographically rotated with respect to each other with a range of angles from about 13 to nearly 30°. Electrical transport measurements performed on back-gated FETs show that overall films with larger domains tend to have higher carrier mobility up to about 16,000 cm(2) V(-1) s(-1) at room temperature.     

Initial Stage Oxidation and Surface Morphology of Modified 9Cr–1Mo Steel at High Temperatures in Air

Modified 9Cr–1Mo steel was oxidized in air at 550 and 750 °C for 25, 100, 250 and 500 h and the oxide scales formed were analysed. The surface morphology and the chemical state of the oxide scales were evaluated using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), respectively. The different exposure temperatures and time showed significant variations on the surface morphologies, the nature of oxide scale, and oxide constituents. The energy dispersive X-ray spectroscopic (EDS) analysis revealed the segregation of Mn at 750 °C even for short exposure time. Grazing incidence X-ray diffraction (GIXRD) patterns revealed the scales to be enriched with haematite and less intense magnetite peaks. Detailed XPS characterization indicated the presence of mixed oxides of iron (Fe), chromium (Cr) and manganese (Mn) in the oxide scales. The Fe–Cr spinel in the oxide scale offered resistance to oxidation of the steel, whereas Mn–Cr spinel was deleterious in nature as it promoted cracking and formation of blisters.