Concentration Of Eluate Research Articles

Antimicrobial properties and biocompatibility of semi-synthetic carbohydrate-based ionic hydrogels.

Hydrogels have gained significant interest in the last decades, especially in the medical sector, due to their versatile properties. While hydrogels from naturally occurring polysaccharides (e.g. cellulose) are well-known, those produced from polymerizable carbohydrate-based monomers remain underexplored. However, these semi-synthetic hydrogels offer the great advantage of having adjustable properties for customization depending on their application. The objective of this study was to characterize semi-synthetic carbohydrate-based ionic hydrogels produced from GVIM-I (glucosyl vinyl imidazolium iodide). The antimicrobial activity was evaluated using the disk diffusion method, which demonstrated that all samples exhibit inhibitory effects on the growth of Candida auris. In vitro biocompatibility was determined by cell viability studies with L929 mouse fibroblasts, and a correlation was observed between eluate concentration and cell viability. In particular, the type of initiator system employed for polymerization was found to affect cell viability. The direct contact assessments showed that specific pre-treatments of the hydrogels resulted in higher cell viability than non-treated hydrogels. The results also revealed the impact of crosslinker concentration and type and identified poly(ethylene glycol)diacrylate (PEGDA) 575 as a promising crosslinker for future medical applications. LC-MS analysis of the wash medium identified unreacted GVIM-I as the leached material, which is presumed to be the cause of the observed cytotoxicity. Overall, the study provides valuable insights into the characteristics of GVIM-I based hydrogels and sheds light on the factors that influence their cytotoxicity and potential for medical application.

Soil pH influences the toxicity of Basamid® eluates to non-target species of primary consumers

Basamid® is a fumigant nematicide and fungicide known to break down in several volatile compounds, mainly methyl isothiocyanate (MITC), when in contact with water. Soil abiotic parameters, such as pH, influences this breakdown process, and thus, the toxic effects of Basamid® to aquatic biota. This work studied the influence of soil pH (5.5, 6.5 and 7.5) on the toxicity of eluates (1:4, m:v), obtained from Basamid®-contaminated soils (with the recommended dose of 145 mg of dazomet/Kg of soil), on two primary consumers: Daphnia magna and Brachionus calyciflorus. For this, lethal and sublethal toxicity of eluates originated from soils at pH 5.5, 6.5 and 7.5, contaminated with Basamid® (Ba-E 5.5; 6.5 and 7.5, respectively), were assessed (dilutions between 0.096 - 100%). The LD50,24h of Basamid® eluates for D. magna varied from 3.07% to 7.82% (Ba-E 6.5 and Ba-E 5.5 respectively), while for B. calyciflorus varied from 18.1% to 84.7% (Ba-E 6.5 and Ba-E 7.5, respectively). Both species were less sensitive to Basamid® eluates originated from soils with pH 7.5 and more sensitive to those obtained from soils with pH 6.5. Regarding the sublethal effects, a lower soil pH was associated with a higher toxicity of Basamid® to D. magna reproduction (LOED: 0.125% Ba-E 5.5), while for B. calyciflorus such a higher toxicity was observed at the highest soil pH (ED20: 7.42% [5.10-9.74] at Ba-E 7.5). These results show a negative association between soil pH and the lethal toxicity of Basamid® contaminated eluates. However, such a pattern was not observed at sublethal level, at which a species dependency was observed regarding the influence of soil pH in the observed toxicity. Nevertheless, it is to highlight that very low concentrations of eluates (as 3.07%) caused significant mortality, indicating a high risk for freshwater biota. Considering that Basamid® is likely to reach the aquatic systems is real, for which reason the recommended dose must be reviewed at environmentally-relevant scenarios.

Solidification of tannery sludge with various binders

The treatment of tannery sludge is an issue that has received considerable attention due to the potential of tannery sludge to cause severe environmental damage. In this study, the solidification process of the waste sludge of the Istanbul Tannery Organize Industry Wastewater Treatment Plant was investigated for safe disposal. The solidification technique was applied using various binders and their different mixtures, such as active carbon, gypsum (CaSO4/2H2O), fly ash, lime (CaO), zeolite, and different cement-sand mixtures on the laboratory scale. The essential parameters such as TOC, fluoride (F- mg/l), chloride (Cl- mg/l), sulfate (SO4= mg/l), chromium (VI) (Cr6+ mg/l), and ammonium (NH4+ mg/l) were determined after solidification process at certain conditions. The analysis results of treated sludge samples were compared to the criteria for storage in the landfills in the Hazardous Waste Control Regulation (HWCR) as well as cost-calculation was done at optimum conditions. After the addition of 10% wt. CaSO4 in the solidification study, the eluate concentration of TOC, Cl- and SO4= was below the limit values. When tannery sludge was solidified using CaO, the necessary criteria could not be obtained. On the other hand, with the addition of 33% CaO and 5% AC mixture TOC and AOX were observed below the limit values. The solidification was occured with mörtel + portland cement and 5% activated carbon additives and the desired limit values in HWCR were succussed for all parameters. Besides, with the addition of 30% zeolite, all parameters declined below the limit values.

Do Self-adhesive Resin Composites Release More Monomers? A Comparative High-performance Liquid Chromatographic Analysis.

To comparatively evaluate the elution of residual monomers (bis-GMA, bis-EMA, TEG-DMA, and HEMA) from two self-adhesive flowable resin composites, a giomer, and a nano-flowable resin composite over five different time intervals, using high-performance liquid chromatography (HPLC). Four flowable resin composites were investigated (Vertise Flow, Constic, Beautifil Flow Plus F03, and Filtek Z350 XT). Immediately after polymerization, each sample was immersed in 75% ethanol/water solution and stored in amber-colored bottles at room temperature. HPLC analysis was performed at predefined time intervals: 1 h, 24 h, 4 days, 8 days and 16 days. The extraction solution was changed after each analysis. Data were analyzed with repeated-measures ANOVA and one-way ANOVA with Tukey's post-hoc test at p < 0.05. The highest mean concentration of residual monomers was eluted from Beautifil, followed by Filtek, and both were significantly higher (p < 0.05) than the mean concentration of eluates from self-adhesive resin composites (Vertise Flow and Constic). Vertise Flow released significantly higher concentrations of HEMA than all the other tested materials. At 1 h post-immersion, 52.2% of monomers were eluted, and continued to elute at a reduced rate throughout the study duration. TEG-DMA was the fastest monomer to leach out, while bis-GMA exhibited significantly higher total mean concentration. The elution rate was significantly dependent on the molecular weight of the eluted monomers. No specific elution behavior can be attributed to self-adhesive RBCs. Elution of residual monomers is dependent on each material's composition, resin matrix characteristics, and the monomer's molecular weight.

Ultrasonic assisted dispersive-solid phase extraction for preconcentration of trace metals in wastewater samples

In this work, MgO-SnO-Zeolite composites material has been synthesized, characterized, and, used as a sorbent material in the determination of Cd, Cr, Mn, Ni, and Zn in water samples using the ultrasonic-assisted dispersive-solid phase extraction. The synthesized MgO-SnO-Zeolite composite was prepared by the co-precipitation method and the results show the crystallinity phase of the material that exhibits most of the zeolite structure. Scanning electron microscopy with energy-dispersive X-ray spectroscopy was conducted on the composite material. The structure of the scanning electron microscopy images shows the cubic material with the energy-dispersive X-ray spectroscopy peaks that confirms the presence of the elements that form part of MgO-SnO-Zeolite. Furthermore, they were no impurities observed on the prepared composite material. The central composite design was used to optimize the adsorption and desorption of the developed ultrasonic-assisted dispersive-solid phase extraction method. The optimum conditions were: pH 7.5, extraction time 17.5 min, adsorbent mass 75 mg, desorption time 5 min, eluate concentration 2 M nitric acid, and desorption volume 7 mL. Under optimum conditions, the limit of detection was found to be 0.13, 0.45, 0.21, 0.34, and 0.08 μgL−1 for Cd, Cr, Mn, Ni, and Zn, with a preconcentration factor of 4.3. The intra-day (n = 15) and inter-day (n = 5) precision expressed as relative standard deviations ranged from 0.4 to 1.3 and 1.34–2.4, respectively. The developed ultrasonic-assisted dispersive-solid phase extraction method was found to be applicable for the determination of Cd, Cr, Mn, Ni, and Zn in wastewater samples.

Distribution of Al, Fe, Si, and DOC between size fractions mobilised from topsoil horizons with progressing degree of podzolisation

Aluminium, Fe, Si, and dissolved organic C (DOC) accumulate in the subsoil of Podzols after mobilisation in the topsoil. We conducted laboratory experiments with topsoil horizons with progressing degree of podzolisation by irrigation with artificial rainwater at varying intensity and permanence. We monitored the concentrations and distribution of mobilised Al, Fe, Si, and DOC between size fractions (< 1000 Dalton, 1 kDa– < 0.45 µm, and > 0.45 µm). Total eluate concentrations were increased at the onset of the experiments and after the first irrigation interruption, indicating non-equilibrium release. There was no statistical effect of the degree of podzolisation on element concentrations. Release of Al, Fe, and DOC was mostly dominant in the fraction 1 kDa– < 0.45 µm, indicating metals complexed by larger organic molecules and colloids. Silicon released was dominantly monomeric silicic acid < 1 kDa. Particularly with the least podzolised soils, Al and Si concentrations < 1 kDa might have been controlled by short-range ordered aluminosilicates, while their transport in colloidal form was unlikely. Our study pointed to both quantitative and qualitative seasonality of element release during podzolisation, to decoupling of Al and Si release regarding size, and to different minerals that control element release as a function of the degree of podzolisation.

Biocompatibility and Antibiofilm Properties of Calcium Silicate-Based Cements: An In Vitro Evaluation and Report of Two Clinical Cases.

Simple SummaryCalcium silicate-based cements are successfully applied in the different fields of endodontics and vital pulp therapy. To better assess the properties of these bioactive materials, the present in vitro and in vivo study aimed to compare the biocompatibility and antibiofilm properties of ProRoot MTA and Biodentine. Human osteogenic sarcoma (Saos-2) cells were cultured in the presence of both materials and evaluated. Moreover, the bioactive cements were in vivo applied to perform vital pulp therapy on immature permanent teeth affected by reversible pulpitis. Saos-2 cells’ viability was slightly greater in the presence of ProRootMTA than Biodentine and cells would grow in a better way on ProRootMTA disks than on Biodentine ones. Moreover, ProRootMTA showed a powerful antibiofilm effect towards Streptococcus mutans. The in vitro results were clinically supported by a 100% success rate after 2 years of follow-up.Calcium silicate-based cements have reached excellent levels of performance in endodontics, providing predictable and successful results. To better assess the properties of these bioactive materials, the present study aimed to compare the biocompatibility and antibiofilm properties of ProRoot MTA and Biodentine. Human osteogenic sarcoma (Saos-2) cells were cultured on ProRoot MTA and Biodentine samples or in the presence of both cement extracts. Cell viability assay, measurement of reactive oxygen species (ROS), immunofluorescence analysis, as well as morphological evaluations were conducted. Moreover, Streptococcus mutans was used to assess the biofilm forming ability on ProRoot MTA and Biodentine disks. Finally, both cements were applied in vivo to treat immature permanent teeth affected by reversible pulpitis. Results: Cell viability assay demonstrated that Saos-2 cells had a dose- and time-dependent cytotoxicity to both analyzed cements, although cells exposed to ProRoot MTA showed a better cell vitality than those exposed to Biodentine (p < 0.001). Both cements demonstrated ROS production while this was greater in the case of Biodentine than ProRoot MTA (p < 0.001). Immunofluorescence images of the cytoskeleton and focal adhesions showed no differences in Saos-2 cells grown in the presence of ProRoot MTA eluate; whereas in the Biodentine groups, cells showed a morphology and focal adhesions more similar to that of the control sample, as the eluate concentration decreased. Morphological analysis revealed that Saos-2 cells were more flattened and exhibited better spreading when attached to ProRoot MTA disks than to Biodentine ones. The antibiofilm properties showed a time-dependent powerful inhibition of S. mutans superficial colonization and an antibiofilm effect of both cements. Clinically, complete root formation of the treated elements was achieved using the two studied cements, showing stable results over time. ProRoot MTA and Biodentine was demonstrated to be biocompatible and to possess antibiofilm properties. Their clinical application in vital pulp therapy provided successful outcomes after 2 years of follow-up.

The effect of surface pre-reacted glass-ionomer filler eluate on dental pulp cells and mineral deposition on dentin: In vitro study.

The effects of surface pre-reacted glass-ionomer (S-PRG) filler on pulpal cells and on the composition of dentinal deposits were investigated. Proliferation (CCK-8), cytotoxicity (LDH), and differentiation activity (ALP) tests, along with cell morphology observations, were conducted at 6 and 24h after treatment of pulpal cells with different S-PRG filler eluate concentrations. Dentinal surfaces were immersed in deionized water or S-PRG filler eluate followed by immersion in deionized water or simulated body fluid and observed under scanning electron microscope and elemental analysis using energy dispersive x-ray spectrometer. At 24h, there were significant differences in CCK-8 and ALP activity values between the groups in a concentration-dependent manner. LDH test data were not significantly different among the groups. Cell morphology was not altered at either exposure time. However, decreased cellular density was observed with the highest eluate concentration. Crystalline deposits and occluded dentinal tubules were observed in samples immersed in S-PRG filler with a later immersion in simulated body fluid, which also showed higher concentrations of certain ions compared to surfaces that were not initially treated with S-PRG filler. The lowest two eluate concentrations did not show significant toxicity. S-PRG enhanced the effect of simulated body fluid in the formation of mineral deposits.

Effects of short-time exposure of surface pre-reacted glass-ionomer eluate on dental microcosm biofilm

This study evaluated the antibacterial effects of short-time exposure of surface pre-reacted glass-ionomer (S-PRG) eluate on oral microcosm biofilm. Biofilms were treated with an S-PRG eluate at different concentrations (25%, 50%, and 100%), distilled water (DW), and 0.1% chlorhexidine (CHX) twice a day for 5 min repeatedly. After 7 days, the total and aciduric bacterial counts and biofilm dry weights were measured. An image analysis program calculated the red/green (R/G) ratios in the biofilm autofluorescence images. Microscopic analyses quantified the biofilm thickness and live/dead cell ratio and determined morphological changes in the biofilm. Bacterial counts and dry weights were not significantly different in the DW group for all S-PRG eluate concentrations. An increasing trend in the R/G ratio for 7 days biofilm treatment was observed for the S-PRG eluate and the DW groups. Furthermore, the live/dead cell ratios in the biofilm and the biofilm thickness of the S-PRG eluate groups were similar to those of the DW group. The bacteria morphology inside the biofilm changed only in the CHX group. Short-time S-PRG eluate treatment showed no significant antibacterial and antibiofilm effects. These results indicated that limited biofilm formation inhibition can be obtained by using only the S-PRG eluate.

Ten-years monitoring of MSWI bottom ashes with focus on TOC development and leaching behaviour

In Switzerland MSWI bottom ash has to comply with the legal threshold value for TOC of < 2 wt-% in order to be landfilled. However, TOC contents of this magnitude lead to elevated DOC emissions and associated emissions of ammonium and Cu (aq). Since 2008 the Canton of Zürich therefore pursues a strategy to lower TOC contents in bottom ash by 2020 to 0.5 wt-%. To observe the development of TOC and other constituents, bottom ash has been monitored from 2008 to 2018. Monitoring results indicate that TOC contents < 0.5 wt-% in bottom ash lead to DOC eluate concentrations < 20 mg/l. DOC concentrations of this magnitude are close to Swiss legal criteria for discharge of landfill leachate into surface waters (10 mg/l). The emission results have been obtained by batch eluate tests according to Swiss Waste Legislation. Such laboratory tests only partially simulate real conditions occurring on landfills. To approximate landfill conditions, column tests with recent bottom ashes combined with tests on simple emission forecasting complete the study. The comparison of results from batch and column tests shows similar cumulative concentrations, indicating that batch tests are suitable to evaluate bottom ash quality. The tested modelling approach, based on constant conditions and exponential decrease in concentration, proved adequate to simulate column progressions. The modelled emission forecasts for DOC lies within 33% of column test results. Further, the model demonstrates the differences in flow regime between eluate tests and landfills and promotes better understanding of temporal aspects and the influence of landfill relevant parameters on pollutant mobilisation.

Improved protein A resin for antibody capture in a continuous countercurrent tangential chromatography system.

Continuous countercurrent tangential chromatography (CCTC) enables steady-state continuous bioprocessing with low-pressure operation and high productivity. CCTC has been applied to initial capture of monoclonal antibodies (mAb) from clarified cell culture harvest and postcapture polishing of mAb; however, these studies were performed with commercial chromatography resins designed for conventional column chromatography. In this study, a small particle size prototype agarose resin (20-25 µm) with lower cross-linking was co-developed with industrial partner Purolite and tested with CCTC. Due to increased binding capacity and faster kinetics, the resulting CCTC process showed more than a 2X increase in productivity, and a 2X reduction in buffer consumption over commercial protein A resins used in previous CCTC studies, as well as more than a 10X productivity increase versus conventional column operation. Single-pass tangential flow filtration was integrated with the CCTC system, enabling simple control of eluate concentration. A scale-up exercise was conducted to provide a quantitative comparison of CCTC and batch column chromatography. These results clearly demonstrate opportunities for using otherwise unpackable soft small particle size resins with CCTC as the core of a continuous bioprocessing platform.

A simple method to immunopurify erthyropoiesis stimulating agents from urine, aiming to optimize erythropoietin screening by SAR-PAGE.

The efficiency of the immunopurification step of urinary erythropoietin (EPO) and recombinant forms is important for their optimal detection in antidoping screening. Previous investigations of immunopurification techniques have been done for immunomagnetic beads, EPO Purification Kit (EPK) columns (MAIIA Diagnostics), and enzyme-linked immunosorbent assay (ELISA) microplates (Stemcell Technologies) conjugated/coated with anti-EPO antibodies. In this study, a new immunopurification technique using anti-EPO sepharose gel beads, developed by MAIIA Diagnostics, to simplify and minimize sample handling was evaluated. This EPO Purification Gel Kit (EPGK) was compared with our current routine EPK for limit of detection (LOD). Linearity, recovery, repeatability, sample incubation time, and sample volume were also evaluated for EPGK. The LODs and linearity for EPK and EPGK were comparable to each other and the recovery for BRP, NESP, CERA, and EPO-Fc were within the range of other studies, and concentration of the sample eluate improved the recovery results. Little variation was seen within days, between days, and between operators. A 90 minute incubation of the sample with the sepharose gel beads is sufficient for most of the erythropoiesis stimulating agents (ESAs) tested, with 10 mL being an optimal sample volume for EPGK. The improved sample handling, higher sample throughput and the reduced working time demonstrate that the EPGK is a better alternative to the current MAIIA EPK immunopurification method for urine. The EPO Purification Gel Kit (from MAIIA Diagnostics) was evaluated and validated for immunopurification of endogenous erythropoietin and exogenous erythropoiesis stimulating agents from urine samples. The kit was a better alternative to that currently used (EPO Purification Kit) in many antidoping laboratories because it improves sample handling and increases sample throughput.

Effect of eluates from zirconia-modified glass ionomer cements on DNA double-stranded breaks in human gingival fibroblast cells

ObjectiveTo formulate novel glass ionomer cements (GICs) containing zirconia (nanoparticles (NPs) and micro-particles (MPs)) and investigate the genotoxic effect of their eluates on DNA double-strand breaks of human gingival fibroblasts (HGFs) in vitro using a γ-H2AX fluorescent assay. MethodsGIC (control, C), 10%ZrO2NPsGIC (T1) and 10%ZrO2MPsGIC (T2) were prepared per the manufacturer’s instructions (hand-mixed, P/L=3.4:1w/w%). Dulbecco’s modified Eagle’s medium (DMEM) was used as the culture medium for HGFs and for eluate preparation. Eluates were collected from all specimens (n=5/g, 5×2mm) after 24h and used for XTT to obtain the EC50 using Graph Pad Prism4. A γ-H2AX immunofluorescence assay was performed to detect DSBs in HGFs. The mean foci per cells and percentage of free foci cells were statistically compared (one-way ANOVA with Tamhane’s post hoc and Chi-square respectively) (p<0.05). Results(1) EC50 ranged from 31 to 36%. 5% and 20% eluate concentrations were selected for the genotoxicity test. (2) Cells exposed to eluates from T1 had lower mean foci per cell than cells in T2 and C eluates (p<0.05). Only cells in T1 at 5% had lower mean foci cell than medium (p<0.05). (3) T1 and C at both concentration showed a higher, but not significant, percentage of free foci cells than negative control (medium). At 20% eluate concentration T2 had a lower percentage of free foci cells than C (p<0.05). SignificanceNano-zirconia GIC and micro-zirconia GIC were formulated. GIC and both zirconia modified GICs had no genotoxic effect on HGFs in vitro. Further studies related to physical properties should be performed to determine the future clinical applications for these novel nanomaterials.

Fabrication of Biodegradable Poly(naringin) Particles with Antioxidant Activity and Low Toxicity

Naringin (NR, 4′,5,7 trihydrocyflavanone-7-O-rhamnoglucoside) is a flavanone found in citrus fruit that is composed of a phenolic compound, naringenin, and a disaccharide, neohesperidose. Poly(NR) [p(NR)] particles in the size range of few micrometers to few hundred nanometers were prepared from highly purified NR and subsequently characterized using UV/visible spectroscopy, Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, scanning electron microscopy, thermogravimetric analysis, and zeta potential measurements. The hydrolytic degradation of p(NR) particles at 37.5 °C was investigated at pHs 5.4, 7.4, and 9.0. The particles degraded most rapidly at pH 7.4, with >90% degradation after 5 h. The cytotoxicity was assessed by growing COS-1 fibroblasts for 5 days in the presence of increasing concentrations of NR or eluates from the p(NR) particles. Both NR and p(NR) particles were nontoxic for these mammalian fibroblasts; at the highest concentration tested (571 μg/mL), the per...

Le calcium phosphate cement imprégné de 10 % de vancomycine délivre une haute concentration antibiotique locale précoce et tardive

BackgroundAntibiotics impregnated calcium phosphate cement (CPC) has emerged as a local treatment of osteomyelitis. However, there is no study investigating the optimal concentrations of vancomycin (VCM) included in CPC to obtain prolonged drug release (≥8 weeks) and also with enough compressive strength (>the normal cancellous bone, 11MPa) for osteomyelitis therapy. Therefore, we bring forward two questions: 1) Was antibiotic activity of the eluates correlated to the load of antibiotics within the cement? 2) Were the mechanical properties of CPC affected by VCM-loading? HypothesizedThere was an optimal concentrations of vancomycin (VCM) loaded in CPC which could provide sufficient effective antibacterial time (≥8 weeks) and enough compressive strength (>11MPa). Materials and methodsCPC specimens were obtained by incorporating different doses (weigh ratios of 0%, 5%, 10%, 15%, 20%, 25 and 30%) of injectable VCM into CPC. The antibacterial effect of released VCM solution against Staphylococcus aureus was assessed by inhibition ring assays. The physicochemical properties such as compressive strengths were characterized and compared among these specimens. ResultsDrug release profiles showed only 5 and 10% VCM-loaded CPC displayed a long enough drug release time (at least 8 weeks) and maintained the eluate concentrations (>4μg/mL) with effective antibacterial ability. The concentration of VCM in 10% group at 8th week was twice higher than 5% group. Compressive strength test showed that the proportional increase of VCM/CPC ratios resulted in a significant decrease of compressive strength (r=−0.906, p<0.001). Conclusion10% VCM-loaded CPC offered the optimal physicochemical properties and drug releasing profile and appears as the most suitable concentration for clinical use. Level of evidenceIII.

Calcium Phosphate Cement loaded with 10% vancomycin delivering high early and late local antibiotic concentration in vitro

BackgroundAntibiotics impregnated calcium phosphate cement (CPC) has emerged as a local treatment of osteomyelitis. However, there is no study investigating the optimal concentrations of vancomycin (VCM) included in CPC to obtain prolonged drug release (≥8 weeks) and also with enough compressive strength (>the normal cancellous bone, 11MPa) for osteomyelitis therapy. Therefore, we bring forward two questions: 1) Was antibiotic activity of the eluates correlated to the load of antibiotics within the cement? 2) Were the mechanical properties of CPC affected by VCM-loading? HypothesizedThere was an optimal concentrations of vancomycin (VCM) loaded in CPC which could provide sufficient effective antibacterial time (≥8 weeks) and enough compressive strength (>11MPa). Materials and methodsCPC specimens were obtained by incorporating different doses (weigh ratios of 0%, 5%, 10%, 15%, 20%, 25 and 30%) of injectable VCM into CPC. The antibacterial effect of released VCM solution against Staphylococcus aureus was assessed by inhibition ring assays. The physicochemical properties such as compressive strengths were characterized and compared among these specimens. ResultsDrug release profiles showed only 5 and 10% VCM-loaded CPC displayed a long enough drug release time (at least 8 weeks) and maintained the eluate concentrations (>4μg/mL) with effective antibacterial ability. The concentration of VCM in 10% group at 8th week was twice higher than 5% group. Compressive strength test showed that the proportional increase of VCM/CPC ratios resulted in a significant decrease of compressive strength (r=−0.906, p<0.001). Conclusion10% VCM-loaded CPC offered the optimal physicochemical properties and drug releasing profile and appears as the most suitable concentration for clinical use. Level of evidenceIII.

Isolation of DNA from small amounts of elephant ivory: Sampling the cementum with total demineralization extraction

Genotyping ivory samples can determine the geographic origin of poached ivory as well as the legality of ivory being sold in ivory markets. We conducted a series of experiments to determine where the DNA is most concentrated in ivory samples and how best to increase DNA yield from groups of samples likely to vary in DNA concentration. We examined variation in DNA amplification success from: the layer(s) of the tusk (cementum and/or dentine) being extracted, demineralization temperature and time, and the concentration of eluates. Since demineralization of the pulverized sample produces a pellet and supernatant, we also assessed DNA amplification success from the pellet, the supernatant, their combination, as well as variation in the respective amounts used for extraction. Our results show that the outer cementum layer of the tusk contains the highest concentration of DNA and should be separated and used exclusively as the source material of ivory processed for extraction, when available. Utilizing the combined demineralized lysate improves extraction efficiency, as does increasing demineralization time to 3 or more days, conducted at 4°C. The most significant improvements occurred for low template DNA ivory samples followed by medium quality samples. Amplification success of high quality samples was not affected by these changes. Application of this optimized method to 3068 ivory samples resulted in 81.2% of samples being confirmed for both alleles at a minimum of 10 out of 16 microsatellite loci, which is our threshold for inclusion in DNA assignment analyses.

Recovering ferulic acid from wheat bran enzymatic hydrolysate by a novel and non-thermal process associating weak anion-exchange and electrodialysis

Abstract Agricultural by-products such as wheat bran and straw are rich in arabinoxylans. Composed of a main chain of β-(1,4) linked xylose ramified by arabinose and ferulic acid, these polymers are sources of valuable molecules, in particular ferulic acid and monomeric (xylose, arabinose and glucose) and oligomeric carbohydrates. Enzymatic hydrolysis using hemicellulasic cocktails obtained from Thermobacillus xylanilyticus provide an eco-friendly alternative to acid or alkaline deconstruction. In this article, downstream purification of the enzymatic hydrolysate of wheat bran with a weak anion-exchange resin (Amberlyst A21- Dow) in free-base form was studied and optimized to reach concentrated ferulate fractions in environment-friendly conditions. A demineralization step by homopolar electrodialysis prior to anion-exchange allowed most of the competing inorganic anions to be removed from the hydrolysate. The capacity of fixation of ferulic acid on the active sites of the resin was increased, as well as purity and concentration of the basic eluate, consequently. Ferulic acid could therefore be crystallized by adjusting the pH of the eluate. 83% was crystallized and purity (NMR) reached 90–95%. At last, 52% of ferulic acid released from wheat bran by the hemicellulasic cocktail was purified and recovered as a solid. Moreover, more than 50 BV (Bed Volume) of the hydrolysate could be recovered during the resin saturation step as rather pure carbohydrates under monomeric (xylose, arabinose and glucose) and oligomeric (xylobiose, xylotriose and xylotetraose) form.

Induction of DNA double-strand breaks in human gingival fibroblasts by eluates from titanium dioxide modified glass ionomer cements

Objectives(1) To investigate the genotoxicity of a glass ionomer cement (GIC) and GIC incorporated with titanium dioxide nanopoarticle (TiO2NPs) and with microparticle (TiO2MPs) on DNA double-strand breaks of human gingival fibroblast cells (HGFs). (2) To compare the genotoxic differences between GIC and two modified cements. MethodsTiO2NPsGIC and TiO2MPsGIC were prepared by adding 10% w/w of TiO2NPs and TiO2MPs to the GIC powder and hand-mixed followed the manufacturer instruction. Dulbecco’s Minimum Essential Medium (DMEM) was used as a culture medium for HGFs and eluate preparation. Eluates from all groups were collected for XTT cell viability assay to obtain EC50 values. γ-H2AX immunofluorescence assay was performed to detect DNA double-strand breaks (DSBs) of HGFs. ResultsEC50 values were from 38% to 60% and eluate concentrations at 20% and 5% were selected for γ-H2AX immunofluorescence assay. At both concentrations, HGFs exposed to eluates from all cements groups had fewer mean foci per cell and higher percentage of free foci cells than H2O2 (p<0.05). At 20% concentration, cells exposed to eluates from both TiO2NPsGIC and TiO2MPsGIC groups had fewer mean foci per cell and higher percentage of free foci cell than GIC and culture medium (p<0.05). SignificanceNeither GIC nor 10% TiO2-modified GICs had a genotoxic effect on HGFs. Both TiO2NPsGIC and TiO2MPsGIC demonstrated less genotoxic effect than GIC. When comparing between the two modified cements, there was no genotoxic difference between the modified cements from different particle sizes (nanoparticle and micro-particle) of TiO2.

A risk-based approach for assessing the recycling potential of an alkaline waste material as road sub-base filler material

In this work we present an integrated risk-based approach that can be used to evaluate the recycling potential of an alkaline waste material such as incineration bottom ash (BA) as unbound material for road sub-base construction. This approach, which is aimed at assessing potential risks to the groundwater resource (in terms of drinking water quality) and human health associated to the leaching of contaminants from the BA, couples the results of leaching tests for the estimation of source concentrations with the fate and transport models usually adopted in risk assessment procedures. The effects of weathering and of the type of leaching test employed to evaluate eluate concentrations were assessed by carrying out different simulations using the results of laboratory leaching tests. Specifically, pH-dependence and column percolation leaching tests were performed on freshly collected and 1-year naturally weathered BA samples produced from a grate-fired incineration plant treating Refuse Derived Fuel (RDF). To evaluate a broad span of possible scenario conditions, a Monte Carlo analysis was performed running 5000 simulations, randomly varying the input parameters within the ranges expected in the field. In nearly all the simulated conditions, the concentrations of contaminants in the groundwater for the specific type of BA tested in this work were well below EU and WHO drinking water quality criteria. Nevertheless, some caution should be paid in the case of the establishment of acidic conditions in the field since in this case the concentration of some elements (i.e. Al, Pb and Zn) is expected to exceed threshold values. In terms of risks to human health, for the considered utilization scenario the probability of exceeding the acceptable reference dose for water ingestion was usually less than 1% (except for Cr and Pb for which the probability was lower than 3.5% and 7%, respectively).