Decontamination Agents Research Articles

DNA Damage Kills Bacterial Spores and Cells Exposed to 222-Nanometer UV Radiation.

This study examined the microbicidal activity of 222-nm UV radiation (UV222), which is potentially a safer alternative to the 254-nm UV radiation (UV254) that is often used for surface decontamination. Spores and/or growing and stationary-phase cells of Bacillus cereus, Bacillus subtilis, Bacillus thuringiensis, Staphylococcus aureus, and Clostridioides difficile and a herpesvirus were all killed or inactivated by UV222 and at lower fluences than with UV254B. subtilis spores and cells lacking the major DNA repair protein RecA were more sensitive to UV222, as were spores lacking their DNA-protective proteins, the α/β-type small, acid-soluble spore proteins. The spore cores' large amount of Ca2+-dipicolinic acid (∼25% of the core dry weight) also protected B. subtilis and C. difficile spores against UV222, while spores' proteinaceous coat may have given some slight protection against UV222 Survivors among B. subtilis spores treated with UV222 acquired a large number of mutations, and this radiation generated known mutagenic photoproducts in spore and cell DNA, primarily cyclobutane-type pyrimidine dimers in growing cells and an α-thyminyl-thymine adduct termed the spore photoproduct (SP) in spores. Notably, the loss of a key SP repair protein markedly decreased spore UV222 resistance. UV222-treated B. subtilis spores germinated relatively normally, and the generation of colonies from these germinated spores was not salt sensitive. The latter two findings suggest that UV222 does not kill spores by general protein damage, and thus, the new results are consistent with the notion that DNA damage is responsible for the killing of spores and cells by UV222IMPORTANCE Spores of a variety of bacteria are resistant to common decontamination agents, and many of them are major causes of food spoilage and some serious human diseases, including anthrax caused by spores of Bacillus anthracis Consequently, there is an ongoing need for efficient methods for spore eradication, in particular methods that have minimal deleterious effects on people or the environment. UV radiation at 254 nm (UV254) is sporicidal and commonly used for surface decontamination but can cause deleterious effects in humans. Recent work, however, suggests that 222-nm UV (UV222) may be less harmful to people than UV254 yet may still kill bacteria and at lower fluences than UV254 The present work has identified the damage by UV222 that leads to the killing of growing cells and spores of some bacteria, many of which are human pathogens, and UV222 also inactivates a herpesvirus.

Enzymatic degradation of deoxynivalenol by a novel bacterium, Pelagibacterium halotolerans ANSP101

Deoxynivalenol (DON), a toxic secondary metabolite produced by Fusarium species that mainly infests cereals such as wheat and corn, threatens human and livestock health. The present study describes the characterization of a novel bacterial strain, Pelagibacterium halotolerans ANSP101 which is capable of transforming DON to less-toxic product 3-keto-deoxynivalenol by the oxidation of the C3 hydroxyl group. Strain ANSP101 was isolated from a seawater sample from a depth of 55 m in Chinese Bohai sea. The strain was identified as Pelagibacterium halotolerans by morphology characterization and 16S rDNA gene sequencing. The DON degrading activity of strain ANSP101 was predominantly attributed to the bacterial cell lysate. Besides, the cell lysate was sensitive to sodium dodecyl sulfate, heat, and proteinase K treatment, indicating that the intracellular proteins or enzymes are responsible for the DON degradation. The optimal temperature and pH for the maximal degradation of DON were 40 °C and pH 8.0 by the cell lysate. These results provide the potential use of P. halotolerans ANSP101 as a detoxification agent for DON decontamination in cereals and feed.

N,P-Doped Carbon Nanodots for Food-Matrix Decontamination, Anticancer Potential, and Cellular Bio-Imaging Applications.

We report a facile one-step thermal treatment method for the synthesis of biocompatible, fluorescent nitrogen-phosphorus-doped carbon nanodots (NPCDs) as multifunctional agents for the food matrix decontamination, cancer targeting, and cellular bio-imaging. NPCDs exhibit high toxicity towards L. monocytogenes, as illustrated by fluorescent live-dead cell counting, disruption of membrane permeability/potential, changes in the levels of cellular ions, genetic materials, and proteins, as well as intracellular production of reactive oxygen species. The tryptophan and protein peaks released in NPCDs treated cells contributed to indole ring breathing and correlated with induced cell death. NPCDs significantly inhibited bacterial biofilm formation on a solid substrate. NPCDs-coated low-density polyethylene (LDPE) film crosslinked with 1% aminopropyltriethoxy silane (APTES) via silane-hydroxyl linking as a food-grade wrap significantly reduced bacterial counts in a raw chicken food model. Furthermore, NPCDs induced apoptosis in HeLa cervical cancer cells, as confirmed by the distorted cell morphology, fluorescence microscopic analysis, presence of fragmented nuclei and the qPCR results of mRNA expression levels of apoptotic markers. Moreover, NPCDs were also applicable in utilized for the cellular bio-imaging of KM12-C colon cancer cells under confocal microscopy owing to their excellent luminescence properties. Overall, NPCDs represent a promising platform to reduce the environmental health risks associated with hazardous pathogens, anticancer targeting, and their application in cellular bio-imaging as multifunctional targets/nanocarriers.

Numerical Simulation for Safety Zone Evolution in Complex Flow Field under Biochemical Attack Scenarios

Fast construction of safety zone has been long desired in the context of chemical attack. In this paper, we propose the use of flow-field control coupled with the decontamination agent technology to minimize the harm and construct the safety zone based on computational fluid dynamics (CFD) software. Aiming at two typical environmental modes, CFD simulations provide great accuracy and more details about distribution of concentration, as well as velocity in spatiotemporal scales. Corresponding experiments are provided for validations. Results reveal the presence of coherent correlation between the airflow state and the evolution of safety zone, which is of great value for the safe design of ventilation system. We hope this work brings inspiration in chemical attack scenarios to reduce casualties.

Effects of continuous exposure to low concentration of ClO2 gas on the growth, viability, and maintenance of undifferentiated MSCs in long-term cultures.

IntroductionHygienic management is more important in the manufacturing of cell products than in the production of chemical agents, because cell material and final product cannot be decontaminated. On the other hand, especially in the selection of hygienic agent, the adverse effects on the cells must be considered as well as the decontamination effect. ClO2 is a potent disinfectant, which is now expected as a safe and effective hygienic agent in the field of cell production. In this study, we investigated the effects of low dose ClO2 gas in the atmosphere of CO2 incubator on the characteristics of MSCs cultured in it.MethodsFirst, we installed a ClO2 generator to a CO2 incubator for cell culture in which a constant level of ClO2 can be maintained. After culturing human cord derived MSCs in the CO2 incubator, the characteristics of cells were analyzed.ResultsContinuous exposure to 0.05 ppmv of ClO2 gas did not affect cell proliferation until at least 8th passage. In the FACS analysis, antigens usually expressed on MSCs, CD105, CD90, CD44, CD73 and CD29, were positively observed, but differentiation markers, CD11b and CD34, were little expressed on the MSCs exposed to 0.05 ppmv or 0.1 ppmv of ClO2 gas just as on the control cells. Also in the investigation for cell death, 0.05 ppmv and 0.1 ppmv of ClO2 gas little affected the viability, apoptosis or necrosis of MSCs. Furthermore, we assessed senescence using SA-β-gal staining. Although the frequency of stained cells cultured in 0.1 ppmv of ClO2 gas was significantly increased than that of not exposed cells, the stained cells in 0.05 ppmv were rare and their frequency was almost the same as that in control.ConclusionsAll these results indicate that, although excessive concentration of ClO2 gas induces senescence but neither apoptosis nor cell differentiation, exposure to 0.05 ppmv of ClO2 gas little affected the characteristics of MSCs. In this study we demonstrate that continuous exposure to appropriate dose of ClO2 gas can be safely used as decontamination agent in cell processing facilities.

Antimicrobial Effects of Zataria multiflora Extract Mouthrinse on Orthodontic Elastomeric Ligatures- an In Vitro Study

Objectives: The aim of this study was to evaluate and compare antibacterial and antifungal effects of different concentrations of Zataria multiflora extract mouthrinse. Methods: In this lab trial study, 128 elastomeric ligatures were divided into 2 groups of 64. Before disinfection eight ligatures of each group were randomly selected to evaluate the microbial load. The remaining ligatures in each group (n = 58) were divided into 7 subgroups of 8. All samples in group 1 (G1) contaminated with Streptococcus mutans (S. mutans) and in group 2 (G2) contaminated with Candida albicans (C. albicans). Then, Zataria multiflora extract in 1%, 0.1%, 0.01%, 0.001%, 0.0001% concentrations as decontamination agent were used in 5 subgroups of each group. Positive control consisted of penicillin in G1 and nystatin in G2. For the negative control in both groups phosphate buffered saline was used. The average number of adhered viable bacterial cell after performing the disinfection protocols were calculated and compared. The collected data was statistically analyzed by Kruskal-wallis, Wilcoxon and Mann-Whitney test using SPSS software version 18 at a significant level of 0.05. Results: Results showed that penicillin, nystatin, Zataria multiflora extract in 1% and 0.1% concentrations completely eliminated C. albicans and S. mutans on elastomeric ligatures. Statistically significant differences were found between the number of adhered S. mutans and C. albicans before and after performing the all five concentrations of disinfection solutions (P = 0.01). Also higher concentrations of Zataria multiflora showed more antibacterial effectse in both groups. Conclusions: Zataria multiflora extract mouthrinse showed antibacterial and antifungal characteristics and could be useful for patients under orthodontic treatment.

Improvement of monitoring requirements over the application of chlorine-containing agents for water decontamination

Introduction. Oxidizing methods are most widely used for water disinfection with such reagents as chlorine, chlorine dioxide, sodium, and calcium hypochlorite. However, the regulatory instruments of the sanitary and epidemiologic legislation do not fully reflect the requirements for monitoring of their use. Materials and methods. We analyzed the research, regulatory and methodological literature concerning water disinfection issues in the process of water treatment and the parameters of water disinfection efficiency as well as the quality of drinking water of three water treatment stations based on production control data (Perm, Russia) and the results of own research (the towns of Nizhny Tagil (Russia) and Curitiba (Brazil)). Results. A comparative analysis of regulatory documents governing the parameters of the efficacy and safety of drinking water disinfection with chlorine in different years showed that, after the completion of the disinfection process of drinking water, residual free chlorine should be kept within 0.3–0.5 mg/L after 30 minutes of contact or residual bound chlorine – within 0.8–1.2 mg/L after 60 minutes of contact. With the simultaneous presence of free and bound chlorine in water, their total concentration should not exceed 1.2 mg/L. When analyzing the production control data for drinking water in the city of Perm, where chloramination was used for water treatment, we established that the concentration range of 1.04–1.44 mg/L of only the residual bound chlorine ensured high efficiency of water disinfection according to microbiological indicators. The examples of water treatment plants in the towns of Nizhny Tagil and Curitiba demonstrated that water treatment with 0.3 and 0.4 mg/L of chlorine dioxide formed no new dangerous organochlorine compounds but the disinfected drinking water contained residual amounts of chlorine dioxide, as well as chlorite and chlorate anions. Conclusion: These indicators should be included in the regulatory documents to monitor the safe use of chlorine dioxide for water disinfection.

β-Cyclodextrin-chitosan biocomposites for synergistic removal of imazethapyr and imazamox from soils: Fabrication, performance and mechanisms

The present study delineates to develop and explore the possibility of using chitosan-β-cyclodextrin biocomposites as environmentally friendly decontamination agent for removal of imazethapyr and imazamox from soils. The biocomposites were synthesised using ultrasonic assisted technique and characterised by UV–Visible spectrophotometer. The quantification of imazethapyr and imazamox was done using liquid chromatography tandem mass spectrometry. The adsorption capacity for imazethapyr and imazamox ranged from 0.12 to 1.22 and 0.02 to 1.01 μg1−ng−1mLn, respectively in studied soils (p < .05) indicating strong influence of soil properties on adsorption. Desorption studies indicated that distilled water could desorb only 1.23 to 5.48 and 3.11 to 8.63% of adsorbed imazethapyr and imazamox, respectively at high concentrations (1.0 and 10 μg mL−1) whereas herbicides were not desorbed at low concentrations (0.01 and 0.1 μg mL−1). The removal of imazethapyr and imazamox from soils were carried out with β-cyclodextrin, chitosan and their biocomposites and the influence of various parameters such as type and concentration of extractant, contact time, liquid to soil ratio, temperature and sequential extraction cycle was investigated. Under optimum conditions, herbicides were successfully desorbed from studied soils using low molecular weight chitosan-β-cyclodextrin biocomposite (LCD) and removal rate varied from 59.42 to 99.44% at initial herbicide concentration of 0.01 to 10 μg mL−1. The highest removal rate of imazethapyr and imazamox was observed for inceptisol 3 followed by entisol, inceptisol 2, aridisol, inceptisol 1, vertisol and alfisol probably due to differential physico-chemical properties of soil which affected the herbicide-soil interactions. Based on these results, LCD can be regarded as effective and environmentally friendly in situ green extracting agent for remediating soils contaminated with imazethapyr and imazamox.

Glucose oxidase-copper hybrid nanoflowers embedded with magnetic nanoparticles as an effective antibacterial agent

Bacterial contamination causes various problems ranging from bacterial infection to biofouling. As an effective and non-toxic agent for bacterial de-contamination, glucose oxidase (GOx)-copper hybrid nanoflowers embedded with amine-functionalized magnetic nanoparticles (NH2-MNPs), called ‘MNP-GOx NFs’, are developed. Positively-charged NH2-MNPs and negatively-charged GOx molecules are first interacted via electrostatic attraction which can be controlled by changing the buffer pH, and the follow-up addition of copper(II) sulfate leads to blooming of nanoflowers (MNP-GOx NFs) after incubation at room temperature for 3 days. MNP-GOx NFs show effective antibacterial activity by generating H2O2 from GOx-catalyzed glucose oxidation. For example, 99.9% killings of Staphylococcus aureus and Escherichia coli are achieved after 3 h treatment of 106/mL cells with 0.2 and 3.0 mg/mL MNP-GOx NFs, respectively, revealing that Gram-positive S. aureus with mono-layer membrane system is more vulnerable to the treatment of MNP-GOx NFs than Gram-negative E. coli with two-layer membrane system. MNP-GOx NFs can maintain 97% of bactericidal activity even after recycled uses by magnetic separation for eight times iterative bacterial killings. Finally, MNP-GOx NFs are employed for the fabrication of antibacterial gauzes. MNP-GOx NFs have also opened up a great potential for their applications in biosensors, biofuel cells and bioconversion as well as bacterial de-contamination.

Quantification of common aminopolycarboxylic acids in trench leachate from the Low Level Waste Repository

The aminopolycarboxylic acids (APCAs), ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA) and nitrilotriacetic acid (NTA), are used as decontamination agents throughout the nuclear industry; therefore, APCAs are often found in radioactive waste. Limits of acceptance on APCAs are imposed on wastes consigned to the Low Level Waste Repository (LLWR) because, when present in the waste, the ligands have the potential to mobilise otherwise surface-bound or solid radionuclides, making them available for transport to groundwater and ultimately to the bio-sphere. A selective and sensitive methodology to detect and quantify these ligands in a range of complex matrices is advantageous in supporting waste acceptance processes. A reversed-phase high-performance liquid chromatography (HPLC) procedure has been applied for quantification of EDTA, DTPA and NTA in their Fe(III)-complex form. Method validation results show linearity (r2 > 0.999), precision (intra/inter-day %RSD ≤ 10%), accuracy (recovery = 100 ± 3%), sensitivity (minimum limits of detection = 0.31, 0.38 and 4.3 μM for EDTA, DTPA and NTA, respectively) and selectivity (simultaneous determination of the three APCA complexes achieved with baseline resolution) for Fe(III)-APCAs in aqueous solution. Chromatographic peak overlap is observed for samples containing Fe(III)- and Co(III)-EDTA; two deconvolution methods (2D least-squares fitting vs. PARAFAC) were applied to resolve the peaks and the performances compared. The optimised HPLC method was applied to trench leachate samples from the LLWR site. EDTA was detected with 0.4 μM < concentrations < 1 μM in samples from four of the six sampling locations tested. The levels are not considered sufficient to increase the risk of radionuclide mobilisation. The technique is considered to be robust and will be considered further in informing limits of acceptance on APCAs.

Post-process treatments are effective strategies to reduce Listeria monocytogenes on the surface of leafy greens: A pilot study

Growth of L. monocytogenes is among the most important factors affecting the risk of human listeriosis. In ready to eat leafy greens, the use of anti-Listeria treatments represents a good alternative to inhibit growth during storage. Several commercially available antimicrobial agents have been suggested as effective intervention strategies. Among them, phage preparations and bacteriocin-producing strains have shown promising results against L. monocytogenes. In this study, we investigate the efficacy of two commercially available surface treatments, the bacteriophage formulation PhageGuard Listex (Micreos Food Safety B.V., NL) and the bacteriocin-producing culture SafePro® (CHR Hansen, DK) to inactivate L. monocytogenes in fresh-cut curly endive after processing and during storage. Fresh-cut endive was inoculated with a cold-adapted L. monocytogenes cocktail of 6 strains (4.4 ± 0.0 log cfu/g) and treated with the anti-Listeria treatments. The treatments were applied using a spray system at two different places within the processing line, on the conveyor belt and in the centrifuge. A total of 5 different treatments were applied: i) Untreated (CT); ii) PhageGuard Listex on the conveyor belt (Listex_Conveyor); iii) PhageGuard Listex during centrifugation (Listex_Centrifuge); iv) SafePro on the conveyor belt (SafePro_Conveyor); and v) SafePro during centrifugation (SafePro_Centrifuge). Samples were stored 3 days at 5 °C plus 5 days at 8 °C. PhageGuard Listex treatment reduced L. monocytogenes in fresh-cut endive by 2.5 logs, regardless of the place of treatment application (conveyor belt or centrifuge). On the other hand, SafePro only reduced L. monocytogenes by 0.2 and 0.4 logs, at the conveyor belt and centrifuge, respectively. Maximum L. monocytogenes reductions of about 3.5 log units were observed in fresh-cut endive treated with PhageGuard Listex after 3 days of storage. At the end of the shelf life (8 days), the initial trends were maintained and the fresh-cut curly endive treated with PhageGuard Listex showed the lowest L. monocytogenes concentration. However, by the end of the shelf-life, L. monocytogenes showed higher levels (1.3-fold) than immediately after the application of the treatment. One hypothesis could be that L. monocytogenes cells, which were able to survive the anti-Listeria treatments, were also able to proliferate under the specific storage conditions. Based on the obtained results, PhageGuard Listex seems to be a promising decontamination agent for leafy greens aiming to reduce growth of the bacteria but further work is needed.

Environmentally benign fabrication of SnO2-CNT nanohybrids and their multifunctional efficiency as an adsorbent, catalyst and antimicrobial agent for water decontamination

Herein, we described a biogenic, additive fee, eco-friendly synthesized SnO2-CNT nanohybrid as an efficient, re-collectable and reusable material for onsite water remediation. We demonstrated that the SnO2-CNTs can provide a one stop solution for water remediation as it effectively accomplished the major treatment tasks like adsorption, catalytic transformation/degradation and disinfection. The structural, morphological, surface chemical compositions of the nanocomposite and the adsorption, catalytic and antimicrobial properties were investigated using common characterization and instrumental techniques. The results revealed the brilliant efficiency of SnO2-CNT nanoadsorbent towards As (III) and a maximum Langmuir adsorption capacity of 106.95 mg/g was observed at high arsenite concentration (C0 = 1 mg/L). The nanoadsorbent was also found to be equally efficient in low arsenite concentration ranges (C0 = 100 μg/L) as it could bring down the arsenic concentration below maximum permissible limit. Moreover, using model pollutants like p-nitrophenol, Alizarin red S, Metronidazole, bacterial strains (Bacillus subtilis, Escherichia coli, Streptococcus pneumonia etc.), and fungal strains (Aspergillus niger and Candida albicans), the multifunctional capability of SnO2-CNT towards water decontamination has been established. Our results suggested the promising potential of hierarchical nano-heterojunctions for engineering efficient water treatment processes.

Evaluate the efficiency of using the phosphoric acid in peri‐implantitis treatment as a decontamination agent

Evaluate the efficiency of using the phosphoric acid in peri‐implantitis treatment as a decontamination agent

Antimicrobial action of octanoic acid against Escherichia coli O157:H7 during washing of baby spinach and grape tomatoes.

We investigated the antimicrobial efficacy of octanoic acid (OA) against Escherichia coli O157:H7 inoculated on the surface of baby spinach and grape tomatoes during simulated washing processes. 3 mM OA at 45 °C achieved >6 log CFU/g reduction from the surface of tomatoes within 2 min. However, washing baby spinach with 6 mM OA at 5 °C resulted in <1 log CFU/g reduction, highlighting the role of surface properties in inactivation efficacy. OA significantly (p < 0.05) reduced the risk of cross-contamination during washing of spinach as well as tomatoes. Also, total mold and yeast population on surface of spinach was significantly reduced immediately after OA wash and inhibited during following 14 days. Baby spinach and grape tomatoes washed with OA did not cause significant (p > 0.05) difference in color compared to the control and no residual OA was detected in most cases following rinsing of produce in water. OA at the concentrations above 2 mM and temperature higher than 25 °C induced severe membrane damage along with release of ATP and other intracellular constituents resulting in bacterial death. OA can be an attractive natural decontamination agent for washing fresh produce.

Study on Chemical Decontamination Process Based on Permanganic Acid-Oxalic Acid to Remove Oxide Layer Deposited in Primary System of Nuclear Power Plant

In accordance with the decommissioning plan for the Kori Unit 1 NPP, the reactor coolant system will be chemically decontaminated as soon as possible after permanent shutdown. This study developed the chemical decontamination process though the development project of decontamination technology of reactor coolant system and dismantled equipment for NPP decommissioning, which has been carried out since 2014. In this study, Oxidation/reduction process was conducted using system decontamination process development equipment of lab scale and was divided into unit and continuous processes. The optimal process time was derived from the unit process, and decontamination agent and the number of process were derived through the continuous processes. Through the unit process, the oxidation process took 5 hours and the reduction process took 4 hours. As optimum decontamination agent, the oxidizing agent was 200 mg·L-1 Permanganic acid + 200 mg·L-1 Nitric acid and the reducing agent was 2000 mg·L-1 Oxalic acid. In the case of the number of processes, all oxide films were removed during the two-cycle chemical decontamination process of STS304 and SA508. In the case of Alloy600, all oxide films were removed when chemical decontamination was performed for three cycles or more.

Antibacterial Povidone-Iodine-Conjugated Cross-Linked Polystyrene Resin for Water Bacterial Decontamination.

Bacterial contamination in water purification systems is generating significant concern as a global health issue. In this paper, we describe fabricating antibacterial povidone-iodine-conjugated cross-linked polystyrene resins (i.e., P(St-DVB-NVP)-I2) and investigating them as antimicrobial agents for water decontamination. Comprehensive antibacterial tests showed that the addition of povidone-iodine to polystyrene resins resulted in strong antibacterial activity against pathogenic bacteria. In addition, the as-synthesized P(St-DVB-NVP)-I2 was confirmed to have hydrophobicity and favorable biocompatibility. We then examined the possibility of using P(St-DVB-NVP)-I2 as an antibacterial filter for water treatment and found that it could efficiently remove bacteria from water. An analog experiment demonstrated that the capability of P(St-DVB-NVP)-I2 for water bacterial decontamination was not influenced by the presence of mineral ions in the water. Most significantly, we confirmed the potential reusability of P(St-DVB-NVP)-I2 through a recycling test. This method of creating an antibacterial resin by building a conjugation of cross-linked polystyrene with povidone-iodine is safe, cost-effective, and environmentally friendly, and the resin shows promise for use in water purification filters.

Study on evaluation of applying flocculating agents for efficient decontamination of radioactively contaminated soil

Study on evaluation of applying flocculating agents for efficient decontamination of radioactively contaminated soil

Stability Evaluation of Hydrogen Peroxide Uptake Samples from Monoclonal Antibody Drug Product Aseptically Filled in Vapor Phase Hydrogen Peroxide-Sanitized Barrier Systems: A Case Study.

During the manufacture of a monoclonal antibody drug product, which was aseptically filled within a vapor phase hydrogen peroxide-sanitized isolator, samples were taken to investigate the hydrogen peroxide uptake behaviors. Surprisingly, the samples had no detectable hydrogen peroxide (most results below the limit of detection). This finding was later attributed to hydrogen peroxide decomposition after the samples were stored frozen at -20°C for two weeks before testing. This case study highlights the criticality of storage conditions for hydrogen peroxide-containing samples and summarizes an investigation on hydrogen peroxide stability in water and in three monoclonal antibody solutions having a wide protein concentration range (30-200 mg/mL). Samples were stored at three temperatures (-70°C, -20°C, or 2-8°C) for up to 28 days to assess the impact of protein concentration and storage temperature on hydrogen peroxide decomposition rates. Hydrogen peroxide degraded slightly more rapidly with increasing protein concentration independent of storage condition. When stored at -20°C, hydrogen peroxide was least stable and degraded faster than when stored at 2-8°C. Hydrogen peroxide was most stable when the samples were stored at -70°C. Overall, this case study brings the hydrogen peroxide stability issue to the attention of process development scientists and engineers and offers a valuable lesson learned during process development.LAY ABSTRACT: The use of vapor phase hydrogen peroxide as a sanitizing agent for isolator and cleanroom decontamination has become common in recent years. Because of the potential impact of residual hydrogen peroxide on biopharmaceutical product quality, hydrogen peroxide uptake behaviors and mechanisms during the manufacturing process within these barriers need to be evaluated and understood. Samples taken from various small-scale and manufacturing-scale hydrogen peroxide uptake studies are often stored frozen before testing. This case study reports an important and interesting finding about hydrogen peroxide stability in samples collected for hydrogen peroxide uptake investigation, and it demonstrates the relationship between hydrogen peroxide stability and storage temperature, storage duration, and monoclonal antibody concentration. The approach and outcome of this study are expected to benefit scientists and engineers who develop biologic product manufacturing processes by providing a better understanding of drug product process challenges and appropriate sample storage.

Organic-nanoclay composite materials as removal agents for environmental decontamination.

Here we overview the recent advances in the fabrication of sustainable composite nanomaterials with decontamination capacity towards inorganic and organic pollutants. In this regards, we present the development of hybrid systems based on clay nanoparticles with different shapes (such as kaolinite nanosheets and halloysite nanotubes) and organic molecules (biopolymers, surfactants, cucurbituril) as efficient removal agents for both aliphatic and aromatic hydrocarbons. Due to their high specific surface area, clay nanoparticles have been successfully employed as fillers for composite membranes with excellent filtration capacity. The preparation of composite gel beads based on biopolymers (alginate and pectin) and halloysite nanotubes has been discussed and their adsorption capacities towards both heavy metals and organic dyes have been highlighted. We describe the successful preparation of kaolinite/graphene composites as well as tubular inorganic micelles obtained by the select functionalization of the halloysite cavity with anionic surfactants. Finally, recent research on Pickering emulsions (for oil spill remediation) and bioremediation technologies has been discussed.

Effective neutralization of chemical warfare agents (HD, VX) by Me-DABCOF: a small molecule with dual action.

The ability of mono N-methyl-1,4-diazabicyclo[2.2.2]octane fluoride (Me-DABCOF, 1) to act as a bifunctional reagent that effectively and universally neutralizes both the persistent and extremely toxic blister agent HD and the nerve agent VX in nearly neutral aqueous solution, alumina powder or a hydrogel formulation, is described.