- Cytotoxicity and Cellular Responses of Gold Nanorods to Smooth Muscle Cells Dependent on Surface Chemistry Coupled Action. [Journal Article]
- SSmall 2018 Nov 14; :e1803715
- Gold nanorods (AuNRs), with their unique physicochemical properties, are recognized as promising materials for biomedical applications. Chemical modification of their surfaces is attracting increasin...
Gold nanorods (AuNRs), with their unique physicochemical properties, are recognized as promising materials for biomedical applications. Chemical modification of their surfaces is attracting increasing attention with regard to cytotoxicity and cellular uptake. Herein, the toxicological effects of three types of polymer-coated AuNRs, which are cetyltrimethylammonium bromide-coated AuNRs, polystyrene sulphonate-coated AuNRs, and poly(diallyldimethyl ammonium chloride-coated AuNRs (PDDAC-AuNRs), on vascular smooth muscle cells (VSMCs) are investigated. The results show significantly different effects on VSMCs with different surface coatings. PDDAC-AuNRs, which were nontoxic in cancer cells in previous reports, display extreme toxicity to VSMCs. Initial contact between AuNRs and cell membranes is the important step in AuNRs cellular uptake. Force spectroscopy based on atomic force microscopy is exploited to study interactions between AuNRs and VSMCs membrane in the absence or presence of a corona on the AuNRs surface. The results show that the binding force and binding probability between AuNRs and membranes are closely related to cytotoxicity and cellular responses. These findings highlight the importance of assessing nanoparticle cytotoxicity in somatic cells for medical applications.
- Determination of acute toxicity of ammonium in juvenile Patagonian blenny (Eleginops maclovinus). [Journal Article]
- BJBraz J Biol 2018 Nov 08
- Deionized ammonium (NH3) acute toxicity (LC50-96h) in Patagonian blenny juveniles (Eleginops maclovinus) was assessed. Concentrations of deionized ammonium in salt water were prepared by using 24.09 ...
Deionized ammonium (NH3) acute toxicity (LC50-96h) in Patagonian blenny juveniles (Eleginops maclovinus) was assessed. Concentrations of deionized ammonium in salt water were prepared by using 24.09 ± 2.1 g ammonium chloride (NH4Cl). Fish were exposed in triplicates to different ammonium concentrations: 0.05; 0.094; 0.175; 0.325 and 0.605 mg NH3 L-1. Additionally, a control group was included. Experimental fish were kept at a photoperiod of 16:8h. Average temperatures were 16.24 ± 1.40 °C. Oxygen concentration was 7.16 ± 0.40 mg L -1. Water pH was 7.89 ± 0.2. LC50-96 h, was estimated by using Probit statistical method (95% intervals) using EPA software (1993). Juveniles of E. maclovinus showed a LC50-96h of 0.413mg NH3 L-1 value, different from most marine species. This study presents the first record of ammonium toxicity in marine species of Chile.
- Concentrating Proteins by Salt, Polyethylene Glycol, Solvent, SDS Precipitation, Three-Phase Partitioning, Dialysis, Centrifugation, Ultrafiltration, Lyophilization, Affinity Chromatography, Immunoprecipitation or Increased Temperature for Protein Isolation, Drug Interaction, and Proteomic and Peptidomic Evaluation. [Journal Article]
- MMMethods Mol Biol 2019; 1855:41-59
- In protein isolation, drug interaction studies, and proteomic or peptidomic procedures, protein solutions are often concentrated to remove solvents and undesirable molecules, to separate protein frac...
In protein isolation, drug interaction studies, and proteomic or peptidomic procedures, protein solutions are often concentrated to remove solvents and undesirable molecules, to separate protein fractions, or to increase protein concentrations. Proteins can be concentrated by precipitation from solution with ammonium sulfate, polyethylene glycol, organic solvents, trichloroacetic acid, potassium chloride/sodium dodecyl sulfate thermal denaturation, and three-phase partitioning. Solvents can be removed by passage through a semipermeable barrier where protein solutions are forced against the barrier in a centrifuge tube or with increased pressure, concentrating proteins in the remaining solution. The semipermeable barrier can be surrounded by a hygroscopic reagent to draw the solvent across the membrane. Proteins can be concentrated by freeze-drying (lyophilization). Unique ligand interactions with proteins can be used to select for proteins by affinity purification or immunoprecipitation. All these methods to concentrate proteins are discussed.
- A bioassay-based protocol for chemical neutralization of human faecal wastes treated by physico-chemical disinfection processes: A case study on benzalkonium chloride. [Journal Article]
- IJInt J Hyg Environ Health 2018 Nov 10
- In situ physico-chemical disinfection of high risk faecal waste is both effective and widely used as a sanitation management strategy for infection prevention and control. Systematic tests where the ...
In situ physico-chemical disinfection of high risk faecal waste is both effective and widely used as a sanitation management strategy for infection prevention and control. Systematic tests where the performance of alternative physico-chemical disinfection methods is systematically compared and optimized must be based on reliable protocols. These protocol are currently not adequately addressing the neutralization related issues: the neutralization of the tested disinfectant after specified conditions of concentration and contact time (CT) is necessary to prevent continued disinfection after the intended contact time; moreover such neutralization is often necessary in practice and on a large scale to prevent adverse health and ecological impacts from remaining disinfectant after the target CT is achieved. Few studies adequately assess the extent of neutralization of the chemical disinfectant and are intended to optimize on-site disinfection practices for waste matrices posing high microbial risks. Hence, there is a need for effective and reproducible neutralization protocols in chemical disinfection trials and practice. Furthermore, for most of chemical disinfectants used in healthcare settings there is no practical methodology to reliably and conveniently measure the residual disinfectant concentration after its neutralization and also determine the optimum concentration of the neutralizer. Because some neutralizing compounds can themselves be toxic to the test microorganisms, it is necessary to optimize neutralization procedures in disinfection experiments for the development of infection control practices using accepted positive control microbes. In the presented work, a stepwise bioassay-based protocol using representative faecal indicator microbes is described for optimizing chemical disinfection and subsequent disinfectant neutralization of any infectious faecal waste matrix. The example described is for the quaternary ammonium compound benzalkonium chloride and its recommended chemical neutralizer in a high strength human faecal waste matrix.
- Metal-Metal Bond Formations in [Au(CN)2-] n ( n = 3, 4, 5) Oligomers in Water Identified by Coherent Nuclear Wavepacket Motions. [Journal Article]
- JPJ Phys Chem Lett 2018 Nov 13
- Large oligomers of [Au(CN)2-] n including pentamer were favorably formed in an aqueous solution containing tetra-ethyl ammonium chloride (1.0 mol/dm3), and intense transient absorption in the visible...
Large oligomers of [Au(CN)2-] n including pentamer were favorably formed in an aqueous solution containing tetra-ethyl ammonium chloride (1.0 mol/dm3), and intense transient absorption in the visible region was recorded by a selective photoexcitation of the oligomers. Distinct oscillations at ~40-100 cm-1 were clearly observed in the temporal profile of the excited-state absorption signal, and the frequency-wavelength two-dimensional analysis of the oscillation clearly distinguishes the coherent nuclear motion of different oligomers. The observed nuclear motions were assigned to Au-Au stretch vibrations in trimer, tetramer and pen-tamer induced by the bond formation in the excited states. The transient absorption exhibits significant changes with the time constant of 3-20 ps, reflecting intersystem crossing and structural change.
- Biodegradation and toxicity of emerging contaminants: Isolation of an exopolysaccharide-producing Sphingomonas sp. for ionic liquids bioremediation. [Journal Article]
- JHJ Hazard Mater 2018 Oct 23; 365:88-96
- Ionic liquids (ILs) have been characterized as contaminants of emerging concern (CEC) that often resist biodegradation and impose toxicity upon environmental release. Sphingomonas sp. MKIV has been i...
Ionic liquids (ILs) have been characterized as contaminants of emerging concern (CEC) that often resist biodegradation and impose toxicity upon environmental release. Sphingomonas sp. MKIV has been isolated as an extreme microorganism capable for biodegradation of major classes of ILs. Six imidazolium-, pyridinium- and ammonium-based ILs (pyridinium trifluoromethanesulfonate [Py][CF3SO3], 1-(4-pyridyl)pyridinium chloride [1-4PPy][Cl], 1-butyl-3-methylimidazolium bromide [BMIM][Br], 1-butyl-3-methylimidazolium methanesulfonate [BMIM][MeSO4], tetrabutylammonium iodide [n-Bu4N][I] and tetrabutylammonium hexafluorophosphate [n-Bu4N][PF6]) were used for microbial growth. The strain achieved 91% and 87% removal efficiency for cultures supplemented with 100 mg L-1 of [BMIM][MeSO4] and [n-Bu4N][I] respectively. The metabolic activity of MKIV was inhibited following preliminary stages of cultures conducted using [BMIM][MeSO4], [BMIM][Br], [Py][CF3SO3] and [n-Bu4N][PF6], indicating potential accumulation of inhibitory metabolites. Thus, a comprehensive toxicological study of the six ILs on Aliivibrio fischeri, Daphnia magna and Raphidocelis subcapitata was conducted demonstrating that the compounds impose moderate and low toxicity. The end-products from [BMIM][MeSO4] and [n-Bu4N][I] biodegradation were assessed using Aliivibrio fischeri, exhibiting increased environmental impact of the latter following biotreatment. MKIV produced 19.29 g L-1 of biopolymer, comprising mainly glucose and galacturonic acid, from 25 g L-1 of glucose indicating high industrial significance for bioremediation and exopolysaccharide production.
- Downregulated Expression of Solute Carrier Family 26 Member 6 in NRK-52E Cells Attenuates Oxalate-Induced Intracellular Oxidative Stress. [Journal Article]
- OMOxid Med Cell Longev 2018; 2018:1724648
- Solute carrier family 26 member 6 (Slc26a6), which is mainly expressed in the intestines and kidneys, is a multifunctional anion transporter that is crucial in the transport of oxalate anions. This s...
Solute carrier family 26 member 6 (Slc26a6), which is mainly expressed in the intestines and kidneys, is a multifunctional anion transporter that is crucial in the transport of oxalate anions. This study is aimed at investigating the effect of Slc26a6 expression on oxalate-induced cell oxidation and crystal formation. Lentivirus transfection was used to upregulate or downregulate Slc26a6 expression in NRK cells. Cell viability and apoptosis, reactive oxygen species (ROS) and malondialdehyde (MDA) generation, and superoxide dismutase (SOD) activity were measured. Crystal adhesion and the cell ultrastructure were observed using light and transmission electron microscopy (TEM). Three groups of rats, normal control, lentivirus-vector, and lentivirus-small interfering RNA (lv-siRNA) groups, were used, and after lentivirus transfection, they were fed 1% ethylene glycol (EG) and 0.5% ammonium chloride (NH4Cl) for 2 weeks. Dihydroethidium (DHE), terminal deoxynucleotidyl transferase (TdT) deoxyuridine dUTP nick-end labeling (TUNEL), and von Kossa staining were performed, and nuclear factor κB (NFκB) and osteopontin (OPN) expression were measured. In the vitro study, compared to the control group, downregulated Slc26a6 NRK cells showed alleviation of the cell viability decrease, cell apoptosis rate, ROS generation, and SOD activity decrease after oxalate treatment. Crystal adhesion and vesicles were significantly less after oxalate exposure than in the untreated controls. Rats infected with lentivirus-siRNA exhibited attenuated SOD generation, cell apoptosis, and crystal formation in the kidneys. Increased phosphorylation of NFκB and OPN was involved in the pathological process. In conclusion, the results of the present study indicate that reducing the expression of Slc26a6 in the kidney may be a potential strategy for preventing stone formation.
- Urothelium proliferation is a trigger for renal crystal deposits in a murine lithogenesis model. [Journal Article]
- SRSci Rep 2018 Nov 05; 8(1):16319
- Most mouse kidney stone models induce nephrocalcinosis rather than urolithiasis. The aim of our study was to find an accelerated experimental model in order to study the early events of stone formati...
Most mouse kidney stone models induce nephrocalcinosis rather than urolithiasis. The aim of our study was to find an accelerated experimental model in order to study the early events of stone formation, that is, at the time of crystal binding to intrarenal urothelium. C57B6 mice exposed to vitamin D supplements and water containing hydroxyl-L-proline, ammonium chloride and calcium chloride were studied for 42 days. A group receiving urothelial cell mitogen Fibroblast Growth Factor 7 (FGF7) was compared to control group receiving saline. Calcium oxalate monohydrate (COM) crystals were detected in urines by day 2 and within urinary spaces in specialized fornix areas in both groups as soon as day 14 with enhanced deposits in FGF7 group compared to controls at day 21. Urothelial cells proliferation, uroplakin III downregulation and de novo expression of osteopontin receptor CD44 detected in FGF7 group, were delayed in the control group (day 42). Crystal aggregates within specialized fornix areas by day 42 were located in urinary spaces but also within and under a multilayered metaplastic urothelium, simultaneous to macrophages influx. Point of note, administration of a normal diet by day 21 was responsible for a spontaneous crystal clearance. Our data show that under supersaturation conditions, urothelial cell proliferation and calcium oxalate crystal retention occur within specialized fornix areas. Enhanced crystal deposits following FGF7 administration suggest that urothelium proliferation would be a relevant trigger for renal stone formation.
- Polyoxometalate based thin film nanocomposite forward osmosis membrane: Superhydrophilic, anti-fouling, and high water permeable. [Journal Article]
- JCJ Colloid Interface Sci 2018 Oct 23; 536:328-338
- Thin-film composite (TFC) membranes with high water flux and low reverse salt flux are the most conventional materials for forward osmosis (FO) process. However, these membranes are not suitable for ...
Thin-film composite (TFC) membranes with high water flux and low reverse salt flux are the most conventional materials for forward osmosis (FO) process. However, these membranes are not suitable for natural or wastewaters treatment due to the intrinsic physicochemical and surface properties of the rejection layer. The present work shows the fabrication of new thin film nanocomposite (TFN) forward osmosis membranes incorporate superhydrophilic modified silica nanoparticles. Surface of silica nanoparticles were functionalized by quaternary ammonium groups and subsequently were coated using superhydrophilic wheel polyoxometalates (POM). TFN membranes containing different weight ratio of nanoparticles in PA rejection layer were synthesized by interfacial polymerization (IP) of m-phenylenediamine (MPD) and trimesoyl chloride (TMC) as monomers in aqueous and organic solution, respectively. POM coated silica nanoparticles were dispersed in aqueous solution of MPD monomer prior to IP process. The changing in the performance and physicochemical properties of TFN membranes incorporating with superhydrophilic nanoparticles were investigated by different instrumental analysis and were compared with a pristine TFC membrane. Compared to pristine TFC membrane, the TFN membrane with 0.2 wt% nanoparticle incorporation (TFNw0.2) showed superior water flux (18 vs. 31 LMH in FO mode) and negligible increases in reverse salt flux (6.25 vs. 8.45 gMH). In addition, better anti-fouling propensity toward protein (bovine serum albumin, BSA) and organic (sodium alginate, SA) foulant was observed. Therefore, Using newly developed thin film nanocomposite membranes may provide a novel class of high-performance membrane for FO processes.
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- Graphene nanoplatelets in potentiometry: A nanocomposite carbon paste and PVC based membrane sensors for analysis of Vilazodone HCl in plasma and milk samples. [Journal Article]
- TTalanta 2019 Feb 01; 193:9-14
- Graphene is the ''new star'' material for electrochemical sensing. It has unique mechanical, thermal and electrical properties, in addition to its ultra light weight. In the present work we combine f...
Graphene is the ''new star'' material for electrochemical sensing. It has unique mechanical, thermal and electrical properties, in addition to its ultra light weight. In the present work we combine for the first time the special features offered by graphene and the advantages of ion selective potentiometric sensors in a single study. We propose two types of sensors, a graphene based carbon paste and a poly vinyl chloride (PVC) based membrane sensors for the analysis of Vilazodone hydrochloride in bulk, human plasma and formula milk samples. Electro active agent is an ion- association complex based on coupling of Vilazodone cationic cite with anionic cite of Molybdate ion in a ratio 1:1. Both sensors are evaluated according to the IUPAC recommendation data, revealing linear response in the concentration range 10-7 - 10-3 and10-8 - 10-3 M with a Nernestian slope 59.89 and 59.91 mV/decade for PVC membrane and Carbon paste sensors, respectively. Both sensors were successfully applied to the analysis of Vilazodone HCl in human plasma and formula milk samples showing good recovery percentage values. Graphene based carbon paste sensor shows several advantages over conventional PVC membrane sensor regarding lower limit of detection, faster response time, longer life time and higher selectivity towards target ion.