Sheep Wool Humidity under Electron Irradiation Affects Wool Sorptivity towards Co(II) Ions.

The effect of humidity on sheep wool during irradiation by an accelerated electron beam was examined. Each of the samples with 10%, 53%, and 97% relative humidity (RH) absorbed a dose of 0, 109, and 257 kGy, respectively. After being freely kept in common laboratory conditions, the samples were subjected to batch Co(II) sorption experiments monitored with VIS spectrometry for different lapses from electron beam exposure. Along with the sorption, FTIR spectral analysis of the wool samples was conducted for cysteic acid and cystine monoxide, and later, the examination was completed, with pH measuring 0.05 molar KCl extract from the wool samples. Besides a relationship to the absorbed dose and lapse, the sorptivity results showed considerable dependence on wool humidity under exposure. When humidity was deficient (10% RH), the sorptivity was lower due to limited transformation of cystine monoxide to cysteic acid. The wool pre-conditioned at 53% RH, which is the humidity close to common environmental conditions, demonstrated the best Co(II) sorptivity in any case. This finding enables the elimination of pre-exposure wool conditioning in practice. Under excessive humidity of 97% RH and enough high dose of 257 kGy, radiolysis of water occurred, deteriorating the sorptivity. Each wool humidity, dose, and lapse showed a particular scenario. The time and humidity variations in the sorptivity for the non-irradiated sample were a little surprising; despite the absence of electron irradiation, relevant results indicated a strong sensitivity to pre-condition humidity and lapse from the start of the monitoring.

LncRNA HOTTIP promotes proliferation and inhibits apoptosis of gastric carcinoma cells via adsorbing miR-615-3p.

OBJECTIVE: To explore the role of long-noncoding ribonucleic acid HOXA transcript at the distal tip (lncRNA HOTTIP) in the proliferation and apoptosis of gastric carcinoma cells. MATERIALS AND METHODS: The expressions of lncRNA HOTTIP in gastric carcinoma cell lines MGC-803, HGC-27, SNU-1, and SGC-7901 and normal gastric mucosa cell line RGM-1 were detected by real-time fluorescence quantitative polymerase chain reaction (PCR) and compared. The effects of lncRNA HOTTIP on proliferation and apoptosis of gastric carcinoma cells were detected by cell counting kit-8 (CCK-8), colony formation assay, and flow cytometry, respectively. StarBase v2.0 website was adopted to predict the relationship between lncRNA HOTTIP and target miRNAs. Dual-Luciferase reporter assay was performed to verify the sponge effect of lncRNA HOTTIP on miR-615-3p. CCK-8 experiment was conducted to detect its effect on proliferation of gastric carcinoma cells after co-silencing lncRNA HOTTIP and miR-615-3p. RESULTS: LncRNA HOTTIP was highly expressed in gastric carcinoma cell lines MGC-803, HGC-27, SNU-1, and SGC-7901 than in normal gastric mucosa cell line RGM-1. After knockdown of lncRNA HOTTIP, the proliferation function of gastric carcinoma cells was markedly weakened, and the proportion of apoptotic cells increased. LncRNA HOTTIP was able to adsorb miR-615-3p via a sponge effect. Notably, knockdown of miR-615-3p restored the effect of silenced lncRNA HOTTIP on the proliferation function of gastric carcinoma cells. CONCLUSIONS: LncRNA HOTTIP is highly expressed in gastric carcinoma cells. It affects cell proliferation and apoptosis in gastric carcinoma by adsorbing miR-615-3p via a sponge effect.

Study of Short Peptide Adsorption on Solution Dispersed Inorganic Nanoparticles Using Depletion Method.

Fundamentals of inorganic-organic interactions are critically important in the discovery and development of novel biointerfaces amenable for utilization in biotechnology and medicine. Recent studies indicate that proteins interact with surfaces through limited adsorption sites. Protein fragments such as amino acids and peptides can be used for interaction modeling between complex biological macromolecules and inorganic surfaces. During the last three decades, many valid and sensitive methods have been developed to measure the physical chemistry fundamentals of those interactions: isothermal titration calorimetry (ITC), surface plasmon resonance (SPR), quartz crystal microbalance (QCM), total internal reflection fluorescence (TIRF), and attenuated total reflectance spectroscopy (ATR). The simplest and most affordable technique for the measurement of adsorption is the depletion method, where the change in sorbate concentration (depletion) after contact with solution-dispersed sorbent is calculated and assumed to be adsorbed. Adsorption isotherms based on depletion data provide all basic physicochemical data. However, adsorption from solutions requires longer equilibration times due to kinetic restrictions and sorbents with a high specific surface area, making it almost inapplicable to macroscopic fixed plane surfaces. Moreover, factors such as the instability of sols, nanoparticle aggregates, sorbent crystallinity, nanoparticle size distribution, pH of the solution, and competition for adsorption, should be considered while studying adsorbing peptides. Depletion data isotherm construction provides comprehensive physical chemistry data for literally every soluble sorbate yet remains the most accessible methodology, as it does not require expensive setups. This article describes a basic protocol for the experimental study of peptide adsorption on inorganic oxide and covers all critical points that affect the process.

Enhanced Cd transport in the soil-plant-atmosphere continuum (SPAC) system by tobacco (Nicotiana tabacum L.).

The optimal treatment designs of the heavy metal pollution sites and the calculation of the recovery capacity are important in recent studies. In this paper, we aimed to model the accumulation of heavy metals under different artificially Cd added concentrations, and analyzed the various tobacco solute adsorption and fluid flow properties. The finite difference method was used to simulate the heavy metals flux and root absorption in the soil, and the model simulation was compared with the measured values to quantify the uncertainty of the metal transport and modeling parameters. Treatments with different Cd levels were compared, e.g., control tillage (CT), low Cd tillage (LT, 2.0 mg/kg), high Cd tillage (HT, 20.0 mg/kg), ultra-high Cd tillage (UHT, 80.0 mg/kg). The predicted soil water content (SWC) was consistent with observed data. Predicted cumulative root water uptake (mm) ranked as follows: CT (196)>LT (178)>HT (134)>UHT (117). Potential transpiration rates (T r p) under HT and UHT were lower than that of other treatment, because of their lower leaf Area Index (LAI). The predicted root Cd uptake showed a strong correlation within the actual Cd uptake. The predicted root absorption of Cdmax was UHT (180.17)> HT (106.52)> LT (53.20) >CT (0.610). However, deviation of models was added by the Cd effluent trend and the performance of root exudates. This finding would be useful for further investigation into bio-remediation in the agricultural area, not only for Cd ion but for a range of other heavy metal contaminants.

Dopamine Binding and Analysis in Undiluted Human Serum and Blood by the RNA-Aptamer Electrode.

Specific analysis of such neurotransmitters as dopamine by the aptamer electrodes in biological fluids is detrimentally affected by nonspecific adsorption of media, particularly pronounced at positive charges of the electrode surface at which dopamine oxidizes. Here, we show that dopamine analysis at the RNA-aptamer/cysteamine-modified electrodes is strongly inhibited in undiluted human serum and blood due to nonspecific interfacial adsorption of serum and blood components. We demonstrate that nonspecific adsorption of serum proteins (but not of blood components) could be minimized when analysis is performed in a flow and injections of serum samples are followed by washing steps in a phosphate buffer solution (PBS) carrier. Under those conditions, the dopamine-aptamer binding affinity in whole human serum of (1.9 ± 0.3) × 104 M-1 s-1 was comparable to the (3.7 ± 0.3) × 104 M-1 s-1 found in PBS, and the dopamine oxidation signal linearly depended on the dopamine concentration, providing a sensitivity of analysis of 73 ± 3 nA µM-1 cm-2 and a LOD of 114 ± 8 nM. The flow-injection apatmer-electrode system was used for direct analysis of basal levels of dopamine in undiluted human serum samples, without using any physical separators (membranes) or filtration procedures. The results suggest a simple strategy for combatting biosurface fouling, otherwise most pronounced at positive electrode potentials used for dopamine detection, and assist in designing more efficient antifouling strategies for biomedical applications.

Use of Adsorbent Biochar from Pequi (Caryocar Brasiliense) Husks for the Removal of Commercial Formulation of Glyphosate from Aqueous Media

Abstract This study evaluated the capacity of adsorbent biochar derived from pequi husks to remove glyphosate (commercial formulation) in aqueous medium under three pH conditions (5.5, 7.0 and 8.0). This biochar presented a mean yield of 33.1% ± 2.66% and a high amount of surface particles of small dimensions endowing it with high surface area. The results showed that removal is proportional to pH increase in the range of 5.5 to 8.0. Adsorption assays performed at pH 7 and 8 fitted better to the Langmuir pseudo-first order kinetics model with fast adsorption in the first 15 to 30 minutes. The results for the acidic pH range fit none of the adopted models satisfactorily. The results obtained suggest that adsorbent can be used as an efficient and inexpensive alternative for the adsorption of glyphosate present in commercial formulations from aqueous matrices.

Colistin Is Extensively Lost during Standard In Vitro Experimental Conditions.

Colistin adheres to a range of materials, including plastics in labware. The loss caused by adhesion influences an array of methods detrimentally, including MIC assays and in vitro time-kill experiments. The aim of this study was to characterize the extent and time course of colistin loss in different types of laboratory materials during a simulated time-kill experiment without bacteria or plasma proteins present. Three types of commonly used large test tubes, i.e., soda-lime glass, polypropylene, and polystyrene, were studied, as well as two different polystyrene microplates and low-protein-binding microtubes. The tested concentration range was 0.125 to 8 mg/liter colistin base. Exponential one-phase and two-phase functions were fitted to the data, and the adsorption of colistin to the materials was modeled with the Langmuir adsorption model. In the large test tubes, the measured start concentrations ranged between 44 and 102% of the expected values, and after 24 h, the concentrations ranged between 8 and 90%. The half-lives of colistin loss were 0.9 to 12 h. The maximum binding capacities of the three materials ranged between 0.4 and 1.1 µg/cm2, and the equilibrium constants ranged between 0.10 and 0.54 ml/µg. The low-protein-binding microtubes showed start concentrations between 63 and 99% and concentrations at 24 h of between 59 and 90%. In one of the microplates, the start concentrations were below the lower limit of quantification at worst. In conclusion, to minimize the effect of colistin loss due to adsorption, our study indicates that low-protein-binding polypropylene should be used when possible for measuring colistin concentrations in experimental settings, and the results discourage the use of polystyrene. Furthermore, when diluting colistin in protein-free media, the number of dilution steps should be minimized.

The art of separation and adsorption: Historical review of apheresis in Japan.

Apheresis therapy was first introduced into Japan from the United State as plasmapheresis by a centrifuge method. However, the invention of hollow fiber has subsequently lead to a membrane plasma separation. Selective removal of the plasma or cell component has been improved and matured in clinical application. Therapeutic apheresis has progressed and diversified with the development of technology for membrane separation by hollow fiber and adsorption with a physicochemical adsorbent in Japan.

Packed-bed column biosorption of chromium(VI) and nickel(II) onto Fenton modified Hydrilla verticillata dried biomass.

The present study represents the first attempt to investigate the biosorption potential of Fenton modified Hydrilla verticillata dried biomass (FMB) in removing chromium(VI) and nickel(II) ions from wastewater using up-flow packed-bed column reactor. Effects of different packed-bed column parameters such as bed height, flow rate, influent metal ion concentration and particle size were examined. The outcome of the column experiments illustrated that highest bed height (25cm); lowest flow rate (10mLmin(-1)), lowest influent metal concentration (5mgL(-1)) and smallest particle size range (0.25-0.50mm) are favourable for biosorption. The maximum biosorption capacity of FMB for chromium(VI) and nickel(II) removal were estimated to be 89.32 and 87.18mgg(-1) respectively. The breakthrough curves were analyzed using Bed Depth Service Time (BDST) and Thomas models. The experimental results obtained agree to both the models. Column regeneration experiments were also carried out using 0.1M HNO3. Results revealed good reusability of FMB during ten cycles of sorption and desorption. Performance of FMB-packed column in treating secondary effluent was also tested under identical experimental conditions. Results demonstrated significant reduction in chromium(VI) and nickel(II) ions concentration after the biosorption process.

Contribution of concentration-sensitive sodium channels to the absorption of alveolar fluid in mice.

The concentration-sensitive sodium channel (Nac) is activated by an increase in the extracellular sodium concentration. Although the expression of Nac in alveolar type II epithelial cells (AEC II) has been reported previously, the physiological role of Nac in the lung has not been established. We characterized Nac expression and examined amiloride-insensitive sodium transport mediated by Nac in mouse lung. Immunofluorescence studies revealed that Nac did not colocalize with either aquaporin 5 or cystic fibrosis transmembrane conductance regulator, but partially colocalized with the epithelial sodium channel γ-subunit. Immunoelectron microscopy studies showed that Nac localized at the basolateral membrane of pulmonary microvascular endothelial cells (PMVECs). Nac mRNA and protein were expressed in PMVECs isolated from the lungs of mice. Image analysis indicated that sodium influx into the alveolar wall was dependent on increases in extracellular sodium concentration. We conclude that Nac expressed in PMVECs and AEC II contributes to the reabsorption of sodium via an amiloride-insensitive pathway during alveolar fluid clearance.

Nutrient depletion modifies cell wall adsorption activity of wine yeast.

Yeast cell wall is a structure that helps yeasts to manage and respond to many environmental stresses. The mannosylphosphorylation is a modification in response to stress that provides the cell wall with negative charges able to bind compounds present in the environment. Phenotypes related to the cell wall modification such as the filamentous growth in Saccharomyces cerevisiae are affected by nutrient depletion. The present work aimed at describing the effect of carbon and/or nitrogen limitation on the aptitude of S. cerevisiae strains to bind coloured polyphenols. Carbon- and nitrogen-rich or deficient media supplemented with grape polyphenols were used to simulate different grape juice conditions-early, mid, 'adjusted' for nitrogen, and late fermentations. In early fermentation condition, the R+G+B values range from 106 (high adsorption, strain Sc1128) to 192 (low adsorption, strain Σ1278b), in mid-fermentation the values range from 111 (high adsorption, strain Sc1321) to 258 (low adsorption, strain Sc2306), in 'adjusted' for nitrogen conditions the values range from 105 (high adsorption, strain Sc1321) to 194 (low adsorption, strain Sc2306) while in late fermentation conditions the values range from 101 (high adsorption, strain Sc384) to 293 (low adsorption, strain Sc2306). The effect of nutrient availability is not univocal for all the strains and the different media tested modified the strains behaviour. In all the media the strains show significant differences. Results demonstrate that wine yeasts decrease/increase their parietal adsorption activity according to the nutrient availability. The wide range of strain variability observed could be useful in selecting wine starters.

Formulation and characterization of taste masked ondansetron-magnesium aluminum silicate adsorption systems.

CONTEXT: Taste masking greatly influences the acceptability of bitter tasting formulation; moreover, it governs the commercial and therapeutic success of drug products. OBJECTIVE: This work is directed toward masking the bitter taste of ondansetron HCl (ONS) utilizing the excipient, which can delay the reach of drug to the taste buds. MATERIAL AND METHODS: Magnesium aluminum silicate (Veegum F), a clay material having capability to adsorb the drugs onto it, was used. The adsorption systems of ONS with Veegum were obtained by dynamic adsorption technique and examined by scanning electron microscopy, differential scanning calorimetry, Fourier transform infrared (FTIR) spectroscopy, and X-ray diffraction (XRD) for morphology, thermal behavior, and interactions. The taste assessment of prepared systems was done by in vitro method based on drug release. RESULTS: The molecular interaction between ONS and Veegum in the system was revealed by FTIR spectroscopy. A change in thermal behavior of the system was observed owing to interaction or replacement of the cationic groups of Veegum with that of ONS. XRD studies revealed that the prepared system was having lower crystallinity as compared to ONS. The in vitro drug release study showed that ONS release from the system was relatively slow in basic environment than the acidic one. DISCUSSION: Adsorption of ONS on the surface of Veegum was mainly due to electrostatic interactions and hydrogen bonding. CONCLUSION: The experimental results reveal the successful intercalation of ONS into the space available between the layers of Veegum. Furthermore, this resulted in a control on drug release in salivary pH resulting in a concentration lower than bitterness threshold.

Adsorption capacity of poly(ether imide) microparticles to uremic toxins.

Uremia is a phenomenon caused by retention of uremic toxins in the plasma due to functional impairment of kidneys in the elimination of urinary waste products. Uremia is presently treated by dialysis techniques like hemofiltration, dialysis or hemodiafiltration. However, these techniques in use are more favorable towards removing hydrophilic than hydrophobic uremic toxins. Hydrophobic uremic toxins, such as hydroxy hipuric acid (OH-HPA), phenylacetic acid (PAA), indoxyl sulfate (IDS) and p-cresylsulfate (pCRS), contribute substantially to the progression of chronic kidney disease (CKD) and cardiovascular disease. Therefore, objective of the present study is to test adsorption capacity of highly porous microparticles prepared from poly(ether imide) (PEI) as an alternative technique for the removal of uremic toxins. Two types of nanoporous, spherically shaped microparticles were prepared from PEI by a spraying/coagulation process.PEI particles were packed into a preparative HPLC column to which a mixture of the four types of uremic toxins was injected and eluted with ethanol. Eluted toxins were quantified by analytical HPLC. PEI particles were able to adsorb all four toxins, with the highest affinity for PAA and pCR. IDS and OH-HPA showed a partially non-reversible binding. In summary, PEI particles are interesting candidates to be explored for future application in CKD.

Development of a high-throughput screening platform to study the adsorption of antigens onto aluminum-containing adjuvants.

Aluminum-containing salts are important adjuvants in the formulations of many licensed human vaccines. However, in the early stage of the design of a new vaccine, a thorough understanding of the adsorption mechanisms of an antigen onto an aluminum salt is required. Therefore, we have developed a robust, rapid, and reproducible high-throughput screening (HTS) platform to study the adsorption capacity of aluminum-containing vaccines. The adsorption isotherms on aluminum hydroxide and aluminum phosphate of two model proteins, ß-casein, and bovine serum albumin, were evaluated using a liquid handling system, which permitted rapid sample preparation in a small volume without nonspecific adsorption. Highly reproducible adsorption capacities and adsorptive coefficients were estimated based on the Langmuir model. To demonstrate the potential of this HTS platform, we evaluated the adsorption isotherms for two antigens, hepatitis B surface antigen and a pneumococcal serotype polysaccharide conjugated to a protein-D carrier, onto aluminum-containing vaccines at either a constant protein or a constant aluminum concentration. The automated assay enabled the rapid quantification of antigen adsorption with a significant reduction in operator workload and reagent use. This platform should accelerate data acquisition during the development of a new vaccine.

Reversibly controlling preferential protein adsorption on bone implants by using an applied weak potential as a switch.

A facile method is needed to control the protein adsorption onto biomaterials, such as, bone implants. Herein we doped taurocholic acid (TCA), an amphiphilic biomolecule, into an array of 1D nano-architectured polypyrrole (NAPPy) on the implants. Doping TCA enabled the implant surface to show reversible wettability between 152° (superhydrophobic, switch-on state) and 55° (hydrophilic, switch-off state) in response to periodically switching two weak electrical potentials (+0.50 and -0.80 V as a switch-on and switch-off potential, respectively). The potential-switchable reversible wettability, arising from the potential-tunable orientation of the hydrophobic and hydrophilic face of TCA, led to potential-switchable preferential adsorption of proteins as well as cell adhesion and spreading. This potential-switchable strategy may open up a new avenue to control the biological activities on the implant surface.

O antigen is the receptor of Vibrio cholerae serogroup O1 El Tor typing phage VP4.

Bacteriophage VP4 is a lytic phage of the Vibrio cholerae serogroup O1, and it is used in phage subtyping of V. cholerae biotype El Tor. Studies of phage infection mechanisms will promote the understanding of the basis of phage subtyping as well as the genetic differences between sensitive and resistant strains. In this study, we investigated the receptor that phage VP4 uses to bind to El Tor strains of V. cholerae and found that it infects strains through adsorbing the O antigen of V. cholerae O1. In some natural isolates that are resistant to VP4 infection, mutations were identified in the wb* cluster (O-antigen gene cluster), which is responsible for the biosynthesis of O antigen. Mutations in the manB, wbeE, and wbeU genes caused failure of adsorption of VP4 to these strains, whereas the observed amino acid residue mutations within wbeW and manC have no effect on VP4 infection. Additionally, although mutations in two resistant strains were found only in manB and wbeW, complementing both genes did not restore sensitivity to VP4 infection, suggesting that other resistance mechanisms may exist. Therefore, the mechanism of VP4 infection may provide a basis for subtyping the phage. Elaborate mutations of the O antigen may imbue V. cholerae strains with resistance to phage infection.

Ionic strength affects tertiary structure and aggregation propensity of a monoclonal antibody adsorbed to silicone oil-water interfaces.

Therapeutic proteins formulated in prefilled syringes lubricated with silicone oil come in contact with silicone oil-water interfaces for their entire shelf lives. Thus, the interactions between protein and silicone oil were studied to determine the effect of silicone oil on a monoclonal antibody's stability, both at the interface and in the bulk solution. The influence of ionic strength on these interactions was also investigated through the addition of various monovalent and divalent salts to sample formulations. The tertiary structure of the antibody was perturbed when it adsorbed to the silicone oil-water interface in solutions at low ionic strength. However, the tertiary structure of the antibody at the interface was not perturbed when the ionic strength of the formulation was increased. Even at low ionic strength, the secondary structure of the antibody adsorbed to the silicone oil-water interface was retained, suggesting that at low ionic strength, the adsorbed antibody assumes a molten globule-like conformation. This partially unfolded species was aggregation-prone, especially during agitation. Silicone oil-induced aggregation of the antibody was inhibited at higher ionic strength.

Adsorptive modulation of inflammatory mediators dampens endothelial cell activation.

AIM: In this study, the effect of specific or selective adsorption of inflammatory mediators on endothelial activation was assessed. METHODS: Conditioned medium was obtained by stimulation of monocytic THP-1 cells with lipopolysaccharide and treated either with an adsorbent specific for tumour necrosis factor-α or with an albumin-coated polystyrene-divinylbenzene copolymer which selectively binds a range of cytokines. Thereafter, the conditioned medium was applied to endothelial cells in culture. RESULTS: Adsorption of inflammatory mediators resulted in significantly decreased endothelial cell activation, as shown by reduced interleukin (IL)-6 and IL-8 secretion from endothelial cells as well as reduced surface expression of the adhesion molecules intercellular adhesion molecule-1 and E-selectin. The effect was more pronounced the earlier the mediator modulation was performed. CONCLUSION: Adsorptive modulation of inflammatory mediators dampens endothelial cell activation and may thus be beneficial as supportive therapy in sepsis.

Carbon adsorbents in oncology: achievements and perspectives.

The results of own investigations and literature data are summarized to determine the place of the main methods of adsorption therapy in complex treatment of the patients with malignant tumors. New possibilities for the usage of new generation of carbon adsorbents and modern adsorptive technologies in cancer treatment are discussed.

Interactions between poly(ethylene glycol) and protein in dichloromethane/water emulsions. 2. Conditions required to obtain spontaneous emulsification allowing the formation of bioresorbable poly(D,L lactic acid) microparticles.

From microscopic observations, it was established that an oil-in-water emulsion with droplets of a size in the micrometer range can spontaneously form at room temperature without additional external stirring as soon as a solvent that is only partly miscible to water-like dichloromethane (DCM) is put in contact with an aqueous mixture of polyethylene glycol (PEG) and a protein. Experimental results show that emulsification only occurs if the system simultaneously includes PEG with middle chain, an organic solvent partly miscible to water and for which PEG affinity is sufficiently high, and a protein. From adsorption kinetics, it appears that this spontaneous emulsification process is related to the rapid diffusion of DCM towards water through the formation of interfacial turbulences, once the accumulation of PEG close to the DCM/water interface occurs. The oil droplets formed would be then stabilized by adsorbed protein molecules. Since the presence of polylactic acid in the organic phase did not prevent the emulsion formation, we studied the feasibility of formulating microparticles using this polymer. From results, it appears that microcapsules with a polymeric shell, with a homogeneous size of about 50 microm and able to encapsulate a model hydrophobic drug, such as amiodarone, can be obtained by using this spontaneous emulsification method.