Decontamination Agents Research Articles

Effectiveness of Different Chemotherapeutic Agents for Decontamination of Infected Dental Implant Surface: A Systematic Review

Aim: To evaluate the most effective chemotherapeutic agent for decontamination of infected dental implants. Material and methods: A systematic electronic literature search in MEDLINE (PubMed) and Google scholar between January 2010 to December 2021 was carried out by using the PRISMA guidelines. A total of five studies related to chemical decontamination of the dental implant were evaluated. The search strategy was based on the PICOS framework. Randomized controlled trials (RCT’s) and cohort studies evaluating the effectiveness of different chemotherapeutic agents for the decontamination of dental implants were included in the study. The outcome variable examined was the most effective chemotherapeutic agent(s) for dental implant surface decontamination after comparing the chemotherapeutic agents used in the qualifying studies. Result: Out of the basic database of 1564 records, 1380 articles were excluded due to irrelevance, unavailability, and repetition. Furthermore, 134 articles were excluded from 184 studies for various reasons. After further filtration, 13 studies were shortlisted. Two investigators (SSA and SA) appraised the quality of the selected studies using the risk of bias assessment tool. After excluding eight studies, five articles were finally included in the present systematic review. Conclusion: The data reported for the efficacy of chemotherapeutic agents in cleaning contaminated titanium surfaces are scarce, thus it is not possible to draw a definite conclusion. However, chlorhexidine (CHX) (0.2%, 0.12%), citric acid (40%) and sodium hypochlorite (1%) are the most commonly used chemotherapeutic agents; amongst them, citric acid showed the highest potential for biofilm removal from the contaminated implant surface. All three agents [CHX (0.2%, 0.12%), citric acid (40%), and sodium hypochlorite (1%)] can be recommended as therapeutic agents along with their curbs.

Potent environmental-friendly virucidal medical textiles against coronavirus to combat infections during the COVID-19 pandemic.

The sudden outburst of Coronavirus disease 19 or COVID-19 has raised serious awareness about viral contamination on the environment, which is one of the major causes of the disease. Transmission via contaminated surfaces has been recognized as a significant route for spreading the virus. To suppress and control the spread of SARS-CoV-2, potent virucidal finishing agents for decontamination of medical textiles are urgently required. In this study, an environmental-friendly, economical, non-toxic, and practical finishing on medical textiles with potent virucidal activity was proposed with the combined concepts of a new green synthesis of TiO2@Ag core-shell nanostructures using ascorbic acid reduction and UV-curing process. In order to evaluate efficiency of virucidal activity, effects of the amount of TiO2@Ag NPs and contact time were determined against the coronavirus following ISO 18184:2019 standard. The finishing agent exhibited an excellent 99.9% virucidal efficacy. The stability of virucidal activity and mechanical properties were determined under repeated washing. The finished fabrics had the ability to retain their virucidal activity and tensile strength through 20 washes. The results suggested that the finishing agent had great potential as a potent and non-toxic virucide against the coronavirus for medical textile applications.

Исследование деконтаминирующей активности дезинфицирующих средств различных классов в отношении нуклеиновых кислот

Contamination of laboratory surfaces with nucleic acids and their amplicons is one of the most important problems encountered in nucleic acid amplification methods due to the occurrence of unreliable results. The aim of this study was to select and determine effective regimens for the use of various active agents for decontamination in PCR laboratories. The ability of ethyl alcohol, alkyldimethylbenzylammonium chloride, N,N-bis(3-aminopropyl)dodecylamine, polyhexamethyleneguanidine hydrochloride, hydrogen peroxide, peracetic acid, chlorine dioxide, sodium hypochlorite and neutral anolyte to destroy or irreversibly modify DNA, preventing its subsequent amplification was studied. The decontamination activity was analyzed by simulating the surface contamination with both long (1500 bp) and short (94 bp) amplicons. Hydrogen peroxide 2?%, peracetic acid 0.24?%, dichloroisocyanuric acid 0.01?%, sodium hypochlorite 0.1?% and chlorine dioxide 0.01?% were shown to have decontaminating ability. Notably, dichloroisocyanuric acid decontaminated surfaces from DNA at a concentration 20 times lower than previously described, and sodium hypochlorite at half the concentration, and chlorine dioxide was also found to have decontaminating activity. The absence of decontaminating activity was observed in ethyl alcohol 70?%, alkyldimethylbenzylammonium chloride 2?%, N,N-bis(3-aminopropyl)dodecylamine 2?%, polyhexamethyleneguanidine hydrochloride 2?% and neutral anolyte 0,05?%. The results obtained allow expanding the list of disinfectants recommended for decontamination measures in laboratories using nucleic acid amplification methods in order to prevent contamination of nucleic acids and their amplicons. Keywords: PCR, DNA, amplicons, decontamination, disinfectants.

Reduction of the Fusarium Mycotoxins: Deoxynivalenol, Nivalenol and Zearalenone by Selected Non-Conventional Yeast Strains in Wheat Grains and Bread.

Mycotoxins, toxic secondary metabolites produced by fungi, are important contaminants in food and agricultural industries around the world. These toxins have a multidirectional toxic effect on living organisms, causing damage to the kidneys and liver, and disrupting the functions of the digestive tract and the immune system. In recent years, much attention has been paid to the biological control of pathogens and the mycotoxins they produce. In this study, selected yeasts were used to reduce the occurrence of deoxynivalenol (DON), nivalenol (NIV), and zearalenone (ZEA) produced by Fusarium culmorum, F. graminearum, and F. poae on wheat grain and bread. In a laboratory experiment, an effective reduction in the content of DON, NIV, and ZEA was observed in bread prepared by baking with the addition of an inoculum of the test yeast, ranging from 16.4% to 33.4%, 18.5% to 36.2% and 14.3% to 35.4%, respectively. These results indicate that the selected yeast isolates can be used in practice as efficient mycotoxin decontamination agents in the food industry.

Efficiency of marketable decontamination agent and graphene oxide on 99mTc and 131I spillages in nuclear medicine department

Dealing with open sources of radioactive substances in nuclear medicine is a daily task since contamination due to radioactive spills may happen frequently. Proper and safe decontamination management is a vital procedure. However, regular purchase of decontamination agents incurs high costs and might be toxic due to their chemical properties. The purpose of this study is to compare graphene oxide, which is an environmentally friendly carbon-based material and marketable decontamination agent, in decontaminating radioactive spillage. Samples of pure 99mTc and 131I from the laboratory were spilled on a petri dish. The spill was immediately decontaminated with a marketable decontamination agent swab and varying concentrations of graphene oxide swab. The initial radioactivity of each swab containing 99mTc and 131I was measured using a dose calibrator. The absorbance spectra of each sample were analysed using an ultraviolet-visible spectrophotometer. The morphology image of graphene oxide was observed under field emission scanning electron microscope. For decontamination using a marketable decontamination agent, the radioactivity of 131I was slightly higher, whereas that of 99mTc was slightly lower than the high concentration of graphene oxide. The absorbance spectra of 99mTc and 131I that had been decontaminated using graphene oxide were observed at a range of 200 nm to 250 nm due ???* to the transition.

A Simple, Rapid, Comparative Evaluation of Multiple Products for Decontamination of Actinide-contaminated Rat Skin Ex Vivo.

Decontamination of skin is an important medical countermeasure in order to limit potential internal contamination by radionuclides such as actinides. Minimizing skin surface contamination will ultimately prevent internal contamination and subsequent committed effective dose as well as contamination spreading. The decontamination agents tested on a rat skin ex vivo model ranged from water to hydrogel wound dressings. A surfactant-containing cleansing gel and calixarene nanoemulsion with chelation properties demonstrated marked decontamination efficacies as compared with water or the chelator DTPA. Based on efficacy to remove different actinide physicochemical forms from skin, the results demonstrate that all products can remove the more soluble forms, but a further component of emulsifying or tensioactive action is required for less soluble forms. This indicates that for practical purposes, successful decontamination will depend on identification of the actinide element, the physicochemical form, and possibly the solvent. This study offers a simple, quick, cheap, reproducible screening method for efficacy evaluation of multiple products for removal of a variety of contaminants.

Keratinases as Versatile Enzymatic Tools for Sustainable Development.

To reduce anthropological pressure on the environment, the implementation of novel technologies in present and future economies is needed for sustainable development. The food industry, with dairy and meat production in particular, has a significant environmental impact. Global poultry production is one of the fastest-growing meat producing sectors and is connected with the generation of burdensome streams of manure, offal and feather waste. In 2020, the EU alone produced around 3.2 million tonnes of poultry feather waste composed primarily of keratin, a protein biopolymer resistant to conventional proteolytic enzymes. If not managed properly, keratin waste can significantly affect ecosystems, contributing to environmental pollution, and pose a serious hazard to human and livestock health. In this article, the application of keratinolytic enzymes and microorganisms for promising novel keratin waste management methods with generation of new value-added products, such as bioactive peptides, vitamins, prion decontamination agents and biomaterials were reviewed.

Exploiting the antiviral potential of intermetallic nanoparticles

Viral pandemic outbreaks cause a significant burden on global health as well as healthcare expenditure. The use of antiviral agents not only reduces the spread of viral pathogens but also diminishes the likelihood of them causing infection. The antiviral properties of novel copper-silver and copper-zinc intermetallic nanoparticles against Escherichia coli bacteriophage MS2 (RNA virus) and Escherichia coli bacteriophage T4 (DNA virus) are presented. The intermetallic nanoparticles were spherical in shape and were between 90 and 120 nm. Antiviral activity was assessed at concentrations ranging from 0.05 to 2.0 wt/v% for 3 and 24 h using DNA and RNA virus model organisms. Both types of nanoparticles demonstrated strong potency towards RNA viruses (> 89% viral reduction), whilst copper-silver nanoparticles were slightly more toxic towards DNA viruses when compared to copper-zinc nanoparticles. Both nanoparticles were then incorporated into polymeric fibres (carrier) to investigate their antiviral effectiveness when composited into polymeric matrices. Fibres containing copper-silver nanoparticles exhibited favourable antiviral properties, with a viral reduction of 75% after 3 h of exposure. The excellent antiviral properties of the intermetallic nanoparticles reported in this study against both types of viruses together with their unique material properties can make them significant alternatives to conventional antiviral therapies and decontamination agents.

Improving Fat Graft Retention with Micro/Nanobubbles in Vivo

PURPOSE: Fat grafting is one of the most popular procedures in plastic and reconstructive surgery.1 However, retention rates of transplanted fat remain variable, often rendering unpredictable outcomes in the long term. Inadequate tissue oxygenation during the transplant process is thought to play a major role in this variability.2 To that end, we sought to examine the implementation of oxygenated micro/nanobubbles (MNBs) during transplantation of lipoaspirate as a means of maintaining adequate tissue oxygenation and improving graft survival. MNBs are small gas bubbles (<100 µm) that are stable for hours and can be saturated with high amounts of oxygen.3 Furthermore, their negative charge and irregular surface characteristics make them an ideal agent for separation and decontamination of charged particulate matter.4 We hypothesize that MNBs will enhance lipoaspirate survival and establish themselves as an important adjunctive step to be incorporated into current fat grafting techniques. METHODS: Twelve 6-week-old Fox Chase SCID beige mice were used as hosts for transplanted human lipoaspirate. Lipoaspirate samples harvested from healthy human donors were washed with either an oxygenated MNB or saline solution prior to injection into the dorsum of the mice. To assess graft viability, explants were harvested at 4-, 8-, and 12-week intervals. Following harvest, grafts were weighed, and volumes were obtained using gas pycnometry. Immunohistochemistry was completed utilizing antibodies directed toward CD31, Perilipin, and CA-9 as surrogates for angiogenesis, adipogenesis, and hypoxia, respectively. Quantitative analysis of IHC images was performed via ImageJ. RESULTS: The grafts that were washed in the MNB solution were significantly greater by mass as early as 4 weeks (P < 0.01). Likewise, an analysis of variance (ANOVA) showed that MNB-washed explants had greater volumes across all time points (P < 0.05). While CD31 staining showed that vessel density was equivocal at each interval between experimental and control groups, perilipin staining showed significantly greater intensity in the MNB group at both 4 and 8 weeks. Moreover, CA-9 staining intensity in the MNB group was notably lower by 12 weeks compared with that in the control group. CONCLUSIONS: The utilization of MNBs, as a source of oxygen, in the wash step prior to transplant may be beneficial for improving graft survival. MNB-washed grafts displayed greater volumes and masses over 12 weeks compared with their control-group saline-washed counterpart. Furthermore, as evidenced by the surrogate markers in the IHC analysis, lipoaspirate samples subjected to the MNB-wash demonstrated improved de novo adipogenesis and less hypoxia. Taken together, these preliminary data reveal promising translatable implications for oxygenated MNBs in the future of fat grafting paradigms. REFERENCES: 1. Simonacci F, Bertozzi N, et al. Procedure, applications, and outcomes of autologous fat grafting. Ann Med Surg (Lond). 2017;20:49–60. 2. Khouri RK, Jr., Khouri RE, et al. Diffusion and perfusion: the keys to fat grafting. Plast Reconstr Surg Glob Open. 2014;2(9):e220. 3. Matsuki N, Ichiba S, et al. Blood oxygenation using microbubble suspensions. Eur Biophys J. 2012;41(6):571–578. 4. Sayadi LR, Ziegler ME, et al. Topical oxygen therapy & micro/nanobubbles: a new modality for tissue oxygen delivery. Int Wound J. 2018;15(3):363–374.

Experience with the evidence map in oral ozone therapy - importance for integrative and complementary health practices

medical and dental treatment in the form of ozonized water and oxygen / ozone gas mixture and associated with photobiomodulation therapy. The evidence map was based on the 3iE evidence searched in the databases: LILACS, PubMed, EMBASE and Cochrane Library, seeking systematic and narrative reviews, analyzed in an excel characterization spreadsheet. Three independent literature reviewers screened the systematic review search output blinded at the software Rayyan. The full-text publications were screened against the specified inclusion criteria by thre independent reviewers; disagreements were resolved through discussion. Forty-two studies were found, 16 of which were systematic reviews and 26 narrative reviews, published between 2006 and 2021, with different levels of confidence. The intervention that most appeared in the literature was oral ozone therapy as a bacterial colony reduction and decontamination agent, with emphasis on topical oxygen-ozone gas mixtures, topical ozonized water. Oral ozone therapy can bring benefits to clinical practice and patients. The evidence map provides an easy visualization of valuable information for patients, health practitioners and managers, in order to promote evidence-based complementary therapies.

Improved detection of Mycobacterium tuberculosis and M. bovis in African wildlife samples using cationic peptide decontamination and mycobacterial culture supplementation.

In South Africa, mycobacterial culture is regarded as the gold standard for the detection of Mycobacterium tuberculosis complex (MTBC) infection in wildlife even though it is regarded as “imperfect.” We compared a novel decontamination and mycobacterial culture technique (TiKa) to the conventional mycobacterium growth indicator tube (MGIT) system using known amounts of bacilli and clinical samples from MTBC-infected African buffaloes (Syncerus caffer), white rhinoceros (Ceratotherium simum), and African elephants (Loxodonta africana). Use of the TiKa-KiC decontamination agent on samples spiked with 10,000 to 10 colony forming units (cfu) of M. bovis (SB0121) and M. tuberculosis (H37Rv) had no effect on isolate recovery in culture. In contrast, decontamination with MGIT MycoPrep resulted in no growth of M. bovis samples at concentrations < 1,000 cfu and M. tuberculosis samples < 100 cfu. Subsequently, we used the TiKa system with stored clinical samples (various lymphatic tissues) collected from wildlife and paucibacillary bronchoalveolar lavage fluid, trunk washes, and endotracheal tube washes from 3 species with known MTBC infections. Overall, MTBC recovery by culture was improved significantly (p < 0.01) by using TiKa compared to conventional MGIT, with 54 of 57 positive specimens versus 25 of 57 positive specimens, respectively. The TiKa mycobacterial growth system appears to significantly enhance the recovery of MTBC members from tissue and paucibacillary respiratory samples collected from African buffaloes, African elephants, and white rhinoceros. Moreover, the TiKa system may improve success of MTBC culture from various sample types previously deemed unculturable from other species.

Application of plasma‐activated water as an antimicrobial washing agent of fresh leafy produce

AbstractPlasma‐activated water (PAW) was investigated as a “green” antimicrobial washing agent for decontamination of ready‐to‐eat rocket salads. PAW was generated using a dielectric barrier discharge jet and the plasma chemistry was correlated to the PAW characteristics. The low helium flow rates favored the NOx formation and resulted also in higher reactive species concentration upon storage. PAW activity was retained even after 12 days of storage at low temperatures. The application of fresh and 7‐days‐stored PAW as washing agents resulted in significant microbial load reduction, whereas the quality indices of PAW‐treated rocket leaves were retained. Finally, the PAW treatment increased the shelf‐life of the leafy salad by a factor of ~2.5 upon storage at 5°C, demonstrating the potential application of plasma technology in the processing and shelf‐life extension of sensitive food products.

Immobilization of Mutant Phosphotriesterase on Fuller’s Earth Enhanced the Stability of the Enzyme

Immobilization is a method for making an enzyme more robust in the environment, especially in terms of its stability and reusability. A mutant phosphotriesterase (YT PTE) isolated from Pseudomonas dimunita has been reported to have high proficiency in hydrolyzing the Sp and Rp-enantiomers of organophosphate chromophoric analogs and therefore has great potential as a decontamination agent and biosensor. This work aims to investigate the feasibility of using Fuller’s earth (FE) as a YT PTE immobilization support and characterize its biochemical features after immobilization. The immobilized YT PTE was found to show improvement in thermal stability with a half-life of 24 h compared to that of the free enzyme, which was only 8 h. The stability of the immobilized YT PTE allowed storage for up to 4 months and reuse for up to 6 times. The immobilized YT PTE showed high tolerance against all tested metal ions, Tween 40 and 80 surfactants and inorganic solvents. These findings showed that the immobilized YT PTE became more robust for use especially with regards to its stability and reusability. These features would enhance the future applicability of this enzyme as a decontamination agent and its use in other suitable industrial applications.

ПРОВЕДЕНИЕ САНИТАРНОЙ ОБРАБОТКИ НА ЭТАПАХ ОКАЗАНИЯ МЕДИЦИНСКОЙ ПОМОЩИ ПОСТРАДАВШИМ В РАДИАЦИОННОЙ АВАРИИ

Purpose: To summarize and analyze the results of research and practical recommendations on the decontamination of victims in the event of radiation accidents, including taking into account the authors’ experience gained in the initial period of the Chernobyl accident (April – August 1986) and in other local radiation accidents (incidents), as well as during emergency exercises.&#x0D; Results: The indications for carrying out decontamination and the technique of its implementation were considered, a comparative assessment of the effectiveness of skin decontamination agents was presented. Recommendations were formulated for determining the priority (urgency) of carrying out decontamination, depending on the level of external radioactive contamination of the victims. Criteria, rules and methods for carrying out decontamination were proposed for use in relation to the practice of medical and hygienic measures at the stages of medical evacuation (accident site, enterprise health center, enterprise sanitary inspection department, triage site, hospital admission department). The features of decontamination of victims with combined radiation injuries and contaminated wounds (burns) were considered, issues of ensuring the radiation safety of medical personnel who provide assistance to victims are touched upon.&#x0D; Conclusion: Timely and correctly performed decontamination reduces the exposure of the skin, prevents the entry of radioactive substances into the body and the transfer (spread) of radioactive substances to the subsequent stages of medical evacuation. The main criteria for the urgency (priority) of carrying out decontamination are the levels of radioactive contamination of the skin, contamination nature (radionuclide composition, physicochemical form, etc.) and the presence of victim’s skin lesions (wounds, burns). Decontamination of victims with high levels of radioactive contamination should be considered as a part of the first and subsequent emergency health care and should be carried out as prescribed or with the direct participation of a healthcare professional. At the stages of medical evacuation, decontamination can be carried out if the victim’s condition is stabilized. In the case of a serious condition of the victim, the priority is evacuation to a hospital, while in the prehospital period, as a rule, only partial decontamination of skin areas with high levels of contamination can be carried out. The procedure and rules for decontamination, including the use of skin decontaminating agents, should be reflected in the action plans of the personnel of radiation hazardous enterprises and the plans for medical support of medical units of the FMBA of Russia.

Usage of a new macro-hierarchical graphene sponge in batch adsorption and packed column configuration for efficient decontamination of cadmium in aqueous environment

Cadmium is one of the most harmful metallic elements which requires immediate measures on its sequestration from polluted aquatic environment. This research emphasised on the development of a new macro-hierarchical graphene oxide configuration as an adsorbing agent for cadmium decontamination in batch and continuous aqueous adsorption systems. The graphene composite was prepared by integrating graphene oxide, xanthan gum and titanium isopropoxide (GO/XG/TI) via a facile freeze-casting approach, using water as the pore forming agent. The batch equilibrium of the new cadmium-GO/XG/TI adsorption system was well predicted by the Freundlich isotherm while the kinetic performance followed closely the pseudo-second-order kinetic correlation. The regeneration results indicated that the adsorbent had the ability to retain 80.75% of its initial adsorption performance even after five successive cycles. A continuous GO/XG/TI aerogel column study was executed for the first time by altering the bed height, feed flowrate and influent concentration. The greatest bed capacity of 64.052 mg/g was attained at a column height of 3 cm, influent cadmium concentration of 100 mg/L and feed flowrate of 2 mL/min. The dynamic column data were correlated to the Adams-Bohart, Thomas and Yoon-Nelson models. Fourier-transform-infrared spectroscopy, point of zero charge and pH studies verified complexation and electrostatic interaction as the dominant mechanisms which anchored the cadmium ions onto the GO/XG/TI adsorbent. The findings from both batch and continuous packed-bed studies supported the use of as-fabricated GO/XG/TI as an efficient purifying agent for the remediation of cadmium in aqueous environment.

Hydrazine Radiolysis by Gamma-Ray in the N2H4-Cu+-HNO3 System.

Radiolysis of chemical agents occurs during the decontamination of nuclear power plants. The γ-ray irradiation tests of the N2H4–Cu+–HNO3 solution, a decontamination agent, were performed to investigate the effect of Cu+ ion and HNO3 on N2H4 decomposition using a Co-60 high-dose irradiator. After the irradiation, the residues of N2H4 decomposition were analyzed by Ultraviolet-visible (UV) spectroscopy. NH4+ ions generated from N2H4 radiolysis were analyzed by ion chromatography. Based on the results, the decomposition mechanism of N2H4 in the N2H4–Cu+–HNO3 solution under γ-ray irradiation condition was derived. Cu+ ions form Cu+N2H4 complexes with N2H4, and then N2H4 is decomposed into intermediates. H+ ions and H● radicals generated from the reaction between H+ ion and eaq− increased the N2H4 decomposition reaction. NO3− ions promoted the N2H4 decomposition by providing additional reaction paths: (1) the reaction between NO3− ions and N2H4●+, and (2) the reaction between NO● radical, which is the radiolysis product of NO3− ion, and N2H5+. Finally, the radiolytic decomposition mechanism of N2H4 obtained in the N2H4–Cu+–HNO3 was schematically suggested.

Çinko Oksit Nanopartiküllerin (ZnO-NP) Önemli Gıda Kaynaklı Patojenler Üzerine İn Vitro Kontaminasyon Etkisi

Zinc oxide (ZnO) has been used for many years in the pharmaceutical, cosmetic, paint, textile, and food industries for coating surfaces, absorbing UV rays and due to its antimicrobial properties in nanoscale it has been identified as important chemical for decontamination. Zinc can be found in many foods as well and its allowed daily intake for adults has been reported as 8-11 mg. Zinc Oxide Nanoparticles (ZnO-NPs) are generally regarded as safe (GRAS) for it being stable under hard processing conditions. Compared to organic acids, ZnO-NPs have better durability, selectivity, and heat resistance. In the present study, it was aimed to understand the decontamination effect of ZnO-NPs on S. enteritidis, S. typhimurium, S. aureus, L. monocytogenes, and E. coli O157 to develop novel, safe decontamination agents for food industry. For this purpose,

Application of Enzyme Indicators in Hydrogen Peroxide Biodecontamination Cycle Development: A Critical Evaluation of Indicator Variability and Correlation to Biological Indicator Results.

An important prerequisite for aseptic production of pharmaceuticals is the appropriate reduction of microbiological contamination. Hydrogen peroxide is commonly applied as decontamination agent for such processes in barrier systems. The development and validation of the barrier decontamination cycles is usually performed with the use of biological indicators (Geobacillus stearothermophilus). However, these indicators inherit certain drawbacks. A new type of indicators became available lately, based on the use of enzyme as a substance decomposed by hydrogen peroxide. There is no broad experience on the practical application of these enzyme indicators yet. Therefore, we investigated the practical use of enzyme indicators in comparison with biological indicators. To broaden the understanding on how these indicators might be used in practice, we provided an evaluation of indicator response variability and the correlation of enzyme indicator results to biological indicator results. In this study, we found the variability of the quantitative enzyme indicator reading to be < 30%, which is much smaller than the variability for spore enumeration of biological indicators (-50% to +300%). Further, we introduced a universal normalization approach to enable convenient comparison and evaluation of different enzyme indicator results. Finally, we discussed a new approach to establish a quantitative correlation between enzyme indicators and biological indicators with the use of threshold values to extrapolate theoretical biological indicator group results. We take the findings of this study as a basis for a suggestion on the practical application of enzyme indicators. We expect that the discussed possibilities of correlating enzyme indicator results to biological indicator results will allow the combined practical use of both indicator types. This would enable the continued application of proven approaches in new ways. Beyond this, the fast reading of enzyme indicators with the gain of significant quantitative information might result in faster and safer qualification and validation of pharmaceutical production equipment in the future.

Non-quaternary oximes detoxify nerve agents and reactivate nerve agent-inhibited human butyrylcholinesterase

Government-sanctioned use of nerve agents (NA) has escalated dramatically in recent years. Oxime reactivators of organophosphate (OP)-inhibited acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) serve as antidotes toward poisoning by OPNAs. The oximes used as therapeutics are quaternary compounds that cannot penetrate the blood–brain barrier (BBB). There remains an urgent need for the development of next generation OPNA therapeutics. We have developed two high-throughput screening (HTS) assays using a fluorogenic NA surrogate, O-ethyl methylphosphonyl O-4-methyl-3-cyano-coumarin (EMP-MeCyC). EMP-MeCyC detoxification and EMP-BChE reactivation screening campaigns of ~155,000 small molecules resulted in the identification of 33 nucleophile candidates, including non-quaternary oximes. Four of the oximes were reactivators of both Sarin- and VX-inhibited BChE and directly detoxified Sarin. One oxime also detoxified VX. The novel reactivators included a non-quaternary pyridine amidoxime, benzamidoxime, benzaldoxime and a piperidyl-ketoxime. The VX-inhibited BChE reactivation reaction rates by these novel molecules were similar to those observed with known bis-quaternary reactivators and faster than mono-quaternary pyridinium oximes. Notably, we discovered the first ketoxime reactivator of OP-ChEs and detoxifier of OPNAs. Preliminary toxicological studies demonstrated that the newly discovered non-quaternary oximes were relatively non-toxic in mice. The discovery of unique non-quaternary oximes opens the door to the design of novel therapeutics and decontamination agents following OPNA exposure.

Green synthesis of spherical TiO2 nanoparticles using Citrus Limetta extract: Excellent photocatalytic water decontamination agent for RhB dye

In this research work, TiO2 nanoparticles has been prepared by eco-friendly green synthesis technique using Citrus Limetta extract which is rarely used. The citric acid present within the extract acted as reducing and capping agent for nanoparticles resulting pure TiO2 nanoparticles. The synthesized nanoparticles are characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), UV–vis spectroscopy and photoluminescence (PL) analysis. The synthesized nanoparticles are approximately 80–100 nm in size, spherical in shape and distribution of the nanoparticles was almost uniform all over the sample. The calculated band gap of nanoparticles was 3.22 eV which confirmed the formation of anatase phase TiO2 nanoparticles. The enhanced photocatalytic activity with respect to time and catalyst concentration was examined for RhB acting as a model dye which is better than many reported results. Almost 90% dye was degraded within 80 min which shows its excellent photocatalytic efficiency.