[en] Short communication

[en] Ethylene Glycol (CAS RN 107-21-1) can to cause kidney toxicity via the formation of calcium oxalate crystals in a variety of species including humans. Numerous repeated dose studies conducted in rats have indicated that male rats are more susceptible than female rats. Furthermore, subchronic and chronic studies using different dietary exposure regimens have indicated that male Wistar rats may be more sensitive to renal toxicity than male F344 rats. This study was, therefore, conducted to compare the toxicity of ethylene glycol in the two strains of rats under identical exposure conditions and to evaluate the potential contribution of toxicokinetic differences to strain sensitivity. Ethylene glycol was mixed in the diet at concentrations to deliver constant target dosage levels of 0, 50, 150, 500, or 1000 mg/kg/day for 16 weeks to groups of 10 male Wistar and 10 male F-344 rats based upon weekly group mean body weights and feed consumption. Kidneys were examined histologically for calcium oxalate crystals and pathology. Samples of blood, urine and kidneys from satellite animals exposed to 0, 150, 500, or 1000 mg/kg/day for 1 or 16 weeks were analyzed for ethylene glycol, glycolic acid and oxalic acid. Treatment of Wistar rats at 1000 mg/kg/day resulted in the death of 2 rats; in addition, at 500 and 1000 mg/kg/day, group mean body weights were decreased compared to control throughout the 16 weeks. In F-344 rats exposed at 1000 mg/kg/day and in Wistar rats at 500 and 1000 mg/kg/day, there were lower urine specific gravities, higher urine volumes, and increased absolute and relative kidney weights. In both strains of rats treated at 500 and 1000 mg/kg/day, some or all treated animals had increased calcium oxalate crystals in the kidney tubules and crystal nephropathy. The effect was more severe in Wistar rats than in F-344 rats. Accumulation of oxalic acid in the kidneys of both strains of rats were consistent with the dose- and strain-dependent toxicity. As the nephrotoxicity progressed over the 16 weeks, the clearance of ethylene glycol and its metabolites decreased, exacerbating the toxicity. Benchmark dose analysis indicated a BMDL05 for kidney toxicity in Wistar rats of 71.5 mg/kg/day; nearly four-fold lower than in F-344 rats (285 mg/kg/day). This study confirms that the Wistar rat is more sensitive to ethylene glycol-induced renal toxicity than the F344 rat and indicates that metabolism plays a role in the strain differences

[en] Full text: A number of new compound esters of acetylenic raw by etherification of oil naphtenic acids with acetylene alcohols and glycols in the presence of the catalyst of cat ion exchange resin KY-2 have been synthesized. It is shown that obtained acetylene esters easily enter into the reaction of hydrosillicylatig, aminoomethylating, of oxidizing, dimerization and hydration generating the new derivatives of oil naphtenic acids and may be applied as anticorrosive additives to motor oils

[en] Present study reports simultaneous batch and column extraction of Pu(IV) and Am(III) followed by selective stripping from actual analytical waste solution generated during quality control operations. N, N, N', N' tetra(2-ethylhexyl) diglycolamide (TEHDGA), di(2-ethylhexyl) phosphoric acid (DEHPA), individually and their combination, encapsulated in polyether sulphone resin beads have been investigated. TEHDGA + DEHPA encapsulated resin showed better performance with respect to kinetics (2 h) and extent of extraction (K_D ∼ 8000 at 5 M nitric acid) for both Am(III) and Pu(IV). Interesting presence of DEHPA, inefficient as extractant at high nitric acid molarity, improved polymer extraction characteristics. Extraction selectivity over assorted metal ions and reusability for three cycles of operations was established. (author)

[en] D-2,3-butanediol is formed by irradiation processes in irradiated liquors. This radiolytic product is not formed in unirradiated liquors and its presence can therefore be used to identify whether a liquor has been irradiated or not. The relation meso/dl∼1 for 2,3-butanediol and the amount present in irradiated liquors may therefore be used as an indication of the dose used in the irradiation. (author)

[en] Full-text: Biomedical nanogels must be free from cytotoxic agents such as carcinogens and irritants which can be associated with nanogels through the use of chemical crosslinkers and accelerants such as N,N-methylenebisacrylamide and tetramethylethylenediamine, respectively. In this study, biocompatible nanogels from N-isopropylacrylamide/polyethylene glycol diacrylate/polyvinyl pyrollidone (NIPAAM/PEGDA/PVP) were synthesized using gamma irradiation-induced copolymerization technique without the need to use any chemical crosslinkers and accelerants. The chemical effects of irradiation dose on the synthesis of the nanogels were studied using Fourier Transform Infra-Red (FTIR) and Nuclear Magnetic Resonance (¹H-NMR). Properties such as molecular weight, radius of gyration, radius of hydration, intrinsic viscosity, and generalized factor were studied using static and dynamic light scattering methods. FTIR analysis revealed that strong peaks corresponding to the out-of-plane deformation vibration of C=C-H at 810 cm^-1 and in-plane deformation vibration of C=C-H at 1407 cm^-1 were almost completely absent in the NIPAAM/PEGDA/PVP nanogel spectra and this is an indication of complete polymerization and monomer depletion. Likewise, in ¹H-NMR spectra the absence of proton resonance of the double bond groups, 5.8 - 6.4 ppm of the nanogels spectrum indicated polymerization has taken place. A new resonance peak was formed at the region, 1.4 - 1.9 ppm) which was due to proton saturation in the polymeric network. Light scattering data shown that highly stable, monodispersed nanogels with the size of around 60 ∼ 110 nm can readily be obtained by manipulating the irradiation doses. In vitro studies proved that the nanogel can be used to enhance the efficacy of curcumin in inhibiting cancer cells growth against MCF-7 and Hep-G2 cancer cell lines. (author)

[en] The objective of the present work was to develop new cationic nanoparticles (cNPs) with amphiphilic cationic copolymers for the delivery of plasmid DNA (pDNA). Cationic copolymers were built on the synthesis of quaternary ammonium salt compounds from diethylenetriamine (DETA) to include the positively charged head group and amphiphilic multi-grafts. PLGA-phe-PEG-qDETA (PPD), phe-PEG-qDETA-PLGA (PDP), and PLGA-phe-PEG-qDETA-PLGA (PPDP) cationic copolymers were created by this moiety of DETA quaternary ammonium, heterobifunctional polyethylene glycol (COOH-PEG-NH₂), phenylalanine (phe), and poly(lactic-co-glycolic acid) (PLGA). These new cNPs were prepared by the water miscible solvent displacement method. They exhibit good pDNA binding ability, as shown in a retardation assay that occurred at a particle size of ∼217 nm. The zeta potential was approximately +21 mV when the cNP concentration was 25 mg/ml. The new cNPs also have a better buffering capacity than PLGA NPs. However, the pDNA binding ability was demonstrated starting at a weight ratio of approximately 6.25 cNPs/pDNA. Gene transfection results showed that these cNPs had transfection effects similar to those of Lipofectamine 2000 in 293T cells. Furthermore, cNPs can also transfect human adipose-derived stem cells. The results indicate that the newly developed cNP is a promising candidate for a novel gene delivery vehicle

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No abstract available

[en] This paper presents results of several years of experimental and theoretical work on a library of oligo(ethylene glycol)-containing self-assembled monolayers (OEG SAMs) on gold. The library consists of 15 different thiol compounds, which all contain alkyl and OEG portions of different length, as well as amide moieties forming a stabilizing lateral hydrogen bonding network. We have investigated the quality, conformation, orientation, defect structure and infrared (IR) signatures of these OEG SAMs prepared by spontaneous adsorption from dilute solutions. It is shown that solution concentration and incubation time are important factors to obtain high quality SAMs, in particular for those containing long OEG chains. Further on, the thiol compounds should contain a sufficiently long alkyl spacer to provide in plane van der Waals interactions strong enough to govern the formation of a densely packed alkylthiolate overlayer on the Au(1 1 1) surface. Such a highly ordered alkyl support, which is additionally stabilized by the lateral hydrogen bonds, enables us to vary the length of the terminal OEG portion from 1 to at least 12, without affecting the integrity and conformational characteristics of the supporting (alkyl) part of the SAM. Also, we discuss the importance of appropriate modeling tools to advance the understanding of IR signatures of the OEG SAMs. Finally, we demonstrate the generality of our 'modular approach' by analyzing the structure of OEG SAMs formed by compounds extended with an additional terminal amide and an alkyl tail. Thus, the SAMs discussed herein provide an attractive platform for construction of advanced nanoarchitectures on surfaces, not only limited to biomaterials and fouling applications.