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Biodeterioration is a significant problem in the conservation of stone heritage buildings. In this study, 10 plant essential oils were assessed for their effectiveness in biofilm inhibition on stone heritage building surfaces under laboratory and in situ conditions, and were compared with traditional biocides such as benzalkonium chloride. The plant extracts were tested against algae and mosses. The effect on algae removal was evaluated by measuring the color of the surface before treatment, after 24 h and after 1 month of treatment. The effect on mosses was assessed by measuring the photosynthetic pigment content of mosses after 24 h of treatment. The results showed that the different plant extracts exhibited different levels of antibiotic activity. Benzalkonium chloride, S. aromaticum and C. cassia extracts showed strong antibiotic activity against all algae and mosses tested. T. mongolicus extracts showed antibiotic activity against only some of the algae and mosses, while the application of P. cablin extracts increased chlorophyll b content in the mosses. The other plant extracts were less effective at inhibiting the growth of algae and mosses. GC–MS compositional analysis further indicated that the higher antibiotic activity of S. aromaticum and C. cassia extracts was related to the high content of eugenol and cinnamaldehyde. [ABSTRACT FROM AUTHOR]

Background: Dry eye is a condition related to long-term topical eye therapy. We wish to evaluate the effectiveness and tolerability of preservative free prostaglandin drops versus benzalkonium chloride containing prostaglandin drops in the treatment of glaucoma. Methods: Patients undergoing prostaglandin monotherapy underwent a washout period of at least 1 month after which baseline measurements of dry eye severity were taken. Patients were randomised to receive either 0.0015% tafluprost drops or 0.005% latanoprost preserved with 0.02% benzalkonium chloride. Repeat measurements were taken after a 2-month interval. Results: Thirty-five patients completed randomised treatment. No significant difference between groups was found in objective and subjective measurements of dry eye severity. No significant difference was found in measurement of treatment effectiveness. Conclusion: Preservative-free and benzalkonium chloride–containing drops were found to be equally effective in lowering IOP with no significant difference in either subjective or objective measurements of dry eye severity. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the toxic effects of benzalkonium chloride (BAC) on Oreochromis mossambicus, a freshwater fish species. Probit analysis was used to determine the lethal concentration (LC50) of BAC for different exposure periods (24, 48, 72, and 96 h). The viability of fish exposed to BAC was assessed using the general threshold survival models (GUTS) and confirmed with relevant datasets to evaluate model accuracy. Experimental groups of fish were exposed to BAC concentrations equivalent to 10% and 20% of the 96-h LC50 for 45 days. The study revealed significant alterations in various parameters during sublethal BAC exposure. These effects included decreased specific growth rate (SGR), red blood cell count (RBC), hemoglobin (Hb) concentration, hematocrit (Ht) value, plasma protein, and albumin levels, as well as acetylcholinesterase (AChE) activities in both gills and liver. Additionally, an increase in gastrosomatic index (GSI), feed conversion ratio (FCR), plasma glucose and creatinine concentrations, alanine aminotransferase (ALT), aspartate aminotransferase (AST) enzymatic activities, catalase (CAT), superoxide dismutase (SOD), and malondialdehyde (MDA) levels were observed in the exposed fish's gills and liver. Furthermore, the study found that glutathione S-transferase (GST) and glutathione peroxidase (GPx) levels initially increased and then decreased in both gills and liver after exposure to BAC. Correlation matrix analysis, multivariate multiple regression (MMR), canonical correspondence analysis (CCA), integrated biomarker response (IBR), and biomarker response index (BRI) were utilized to assess the impact of BAC on fish, highlighting significant effects on multiple biomarkers in O. mossambicus following surfactant exposure. Thus, the study provides valuable insights into the toxic effects of BAC on this fish species, emphasizing the importance of monitoring such pollutants in aquatic environments. [ABSTRACT FROM AUTHOR]

In this work, we demonstrate that a simple argentometric titration is a scalable, fast, green and robust approach for producing AgCl/antibiotic hybrid antimicrobial materials. We titrated AgNO3 into tetracycline hydrochloride (TCH) aqueous solution, thus forming AgCl/TCH in a one-step procedure. Furthermore, we investigated the one-pot synthesis of triply synergistic super-nanoantimicrobials, combining an inorganic source of Ag+ ions (AgCl), a disinfecting agent (benzyl-dimethyl-hexadecyl-ammonium chloride, BAC) and a molecular antibiotic (tetracycline hydrochloride, TCH). Conventional antimicrobial tests, industrial biofilm detection protocols, and in situ IR-ATR microbial biofilm monitoring, have been adapted to understand the performance of the synthesized super-nanoantimicrobial. The resulting hybrid AgCl/BAC/TCH nanoantimicrobials are found to be synergistically active in eradicating Salmonella enterica and Lentilactobacillus parabuchneri bacteria and biofilms. This study paves the way for the development of a new class of super-efficient nanoantimicrobials that combine relatively low amounts of multiple active species into a single (nano)formulation, thus preventing the development of antimicrobial resistance towards a single active principle. [ABSTRACT FROM AUTHOR]

Background: Corneal tissues indirectly obtain nutritional needs and oxygen to maintain their homeostasis, and therefore, benzalkonium chloride (BAC) containing ocular instillations for medical therapy may, in turn, induce toxic effects more than expected in corneal tissues, especially the inside stroma layer. Methods: To evaluate the effects of very low concentrations (10−8%, 10−6%, or 10−4%) of BAC on human corneal stroma, we used two-dimensional (2D) cultures of human corneal stromal fibroblast (HCSF) cells and carried out the following analyses: (1) cell viability measurements, (2) Seahorse cellular bio-metabolism analysis, and (3) the expression of ECM molecules and endoplasmic reticulum (ER) stress–related molecules. Results: In the absence and presence of 10−8%, 10−6%, or 10−4% concentrations of BAC, cell viability deteriorated and this deterioration was dose-dependent. The results showed that maximal mitochondrial respiration was decreased, the mRNA expression of most of ECM proteins was decreased, and ER stress–related molecules were substantially and dose-dependently down-regulated in HCSFs by the BAC treatment. Conclusions: The findings reported herein indicate that the presence of BAC, even at such low concentrations, is capable of causing the deterioration of cellular metabolic functions and negatively affecting the response to ER stress in HCSF cells resulting in a substantially decreased cellular viability. [ABSTRACT FROM AUTHOR]

The effects of benzalkonium chloride (BC) as a cationic surfactant on the mechanical, water barrier, microstructural, and thermal properties of adlay millet starch (AS) films were investigated in this study. With increasing BC concentration, tensile strength (from 5.93 to 6.15 MPa) and elongation at break (from 41.39 to 45.48%) of AS-BC films significantly increased, whereas their moisture content, water solubility, and water vapor permeability were reduced, indicating water resistance improvement. Fourier transform infrared spectroscopy and scanning electron microscopy analysis showed that BC at concentrations below 1% did not cause noticeable changes in the microstructure of AS-BC films. In addition, the thermal stability of AS-BC films was not affected by BC, indicating good miscibility between AS and BC. Therefore, BC could improve the physicochemical properties of starch films, and AS-BC films developed in this study can be applied as novel biodegradable packaging materials in the food packaging industry. [ABSTRACT FROM AUTHOR]

The widespread occurrence of multi-resistant bacteria is a health problem of global dimension. Infections caused by multi-resistant pathogens are difficult to treat and often associated with high mortality. Therefore, new treatment strategies are of interest, such as the use of differently acting antibacterial concepts. One of these new concepts is the use of antiseptics in combination with the antibacterial photodynamic therapy (aPDT). Currently, no method has yet been established as a standard procedure for investigating combined effects and evaluating them in a generally valid and unambiguous manner. The focus of this study was on how cationic antiseptics benzalkonium chloride (BAC) and chlorhexidine digluconate (CHX) behave in a combined application with aPDT using the photosensitizer TMPyP. For this purpose, BAC and CHX were applied in combination with the aPDT using TMPyP in non-lethal concentrations to the three bacteria Escherichia coli, Staphylococcus aureus, and Enterococcus faecalis. The results of the combination experiments with sublethal concentrations of BAC or CHX with the aPDT showed that the binary application had a lethal effect. Irrespective of the bacteria, the reduction in concentrations in OPECC, compared to individual concentrations, was more than 50% for TMPyP, 23–40% for BAC, and 18–43% for CHX. Furthermore, the optimal effective concentration combinations (OPECCs) could be determined. The latter showed that the combined application allowed the reduction of both concentrations compared to the single application. [ABSTRACT FROM AUTHOR]

A simple microextraction method has been developed for the preconcentration of Au(III) and its measurement by an ultraviolet–visible spectrophotometer. Benzalkonium chloride, a cationic surfactant, was used as a complexing agent for the preconcentration of Au(III) in the form of AuCl4−. An ion pair between AuCl4− and benzalkonium chloride was finely extracted into the 1,2-dichloroethane phase through a simple emulsification process. Parameters affecting the preconcentration of Au(III) were evaluated, including the acidity of the solution, the amount of the cationic reagent, and the effect of interferences. The calibration curve of the method for Au(III) was linear in the range of 0.05–0.80 mg L−1. The detection limit, enrichment factor, and relative standard deviation were 0.01 mg L−1, 40, and 1.9%, respectively. The accuracy of the method was evaluated through addition-recovery tests on real water samples. The results demonstrate that this microextraction method was successfully applied to stream water samples for the preconcentration of Au(III). [ABSTRACT FROM AUTHOR]

Ion selective electrodes (ISEs) based on polymer plasticized membranes have been developed for the determination of benzalkonium chloride (alkyldimethylbenzylammonium), the active component being cesium bis-octodecyl-2-sulfonio-closo-decaborate Cs[B10H9S(C18H37)2] (sensor A). For the determination of norfloxacin hydrochloride, the active component is potassium tris-octodecyl-1-ammonio-closo-decaborate K[B10H9N(C18H37)3] (sensor B). It has been shown that the electrodes have a reversible potentiometric response with respect to the analyzed cations in the presence of a number of other inorganic and organic cations. The influence of the concentration of the electrode-active substance on the electrochemical characteristics of the manufactured sensor has been studied. The optimal composition of the ion-sensitive membrane has been found. It has been determined that the developed sensors provide a wide range of detectable concentrations (for sensor A, 2 × 10–7–1 × 10–2; for sensor B, 1 × 10–7–1 × 10–2) and a low detection limit (for sensor A, 1 × 10–7 M; for sensor B, 8 × 10–8 M). New ISEs can be recommended for direct potentiometric detection of free ions in water bodies and water extracts of soils. [ABSTRACT FROM AUTHOR]

Ophthalmic preparations that contain ketorolac tromethamine (KET) and olopatadine HCl (OLO) are used to relieve seasonal allergies and allergic conjunctivitis. Simultaneous quantification of KET and OLO was held by validated and simple spectrophotometric methods. KET was determined directly from the fundamental UV absorption spectra (at 323 nm), while OLO was determined after performing either dual wavelength or ratio derivative methods. The first method was based on measuring the absorbance difference (ΔA) between 243 and 291 nm, while the second depended on generating first derivative ratio spectra using 3.0 µg/mL KET as a divisor and measuring OLO responses at 234 nm (minima). Multiple standard addition method was applied to enable the determination of OLO which is considered as the weakly absorbing species as well as the minor component in a challenging dosage form ratio (4:1). The linearity ranges of the developed methods were 3–12 μg/mL and 4–40 μg/mL for KET and OLO, respectively. Simultaneous determination of both drugs was successfully implemented to lab prepared eye drops that contain KET, OLO and benzalkonium chloride as an inactive ingredient. Greenness assessment indicates minimal impact on environment. The developed methods determined the cited drugs with % recovery ± SD of 99.63 ± 0.01 for KET, 100.90 ± 0.02 and 100.31 ± 0.01 for OLO using dual wavelength and first derivative ratio methods, respectively. Using F-test and t-test at confidence level %95 to compare between the results of the presented methods and a reported method show no significant difference which allows precise, accurate, rapid, and simple quantification of quality control samples that contain KET and OLO. [ABSTRACT FROM AUTHOR]

The accuracy of environmental DNA (eDNA) methods developed as innovative biological monitoring technologies can be improved by considering the ecological characteristics of a target species. In this study, we performed an aquarium experiment and field surveys to establish an effective eDNA method for an endangered Japanese bagrid catfish (Pseudobagrus ichikawai) with nocturnal habits. First, we developed a species-specific eDNA method using quantitative real-time polymerase chain reaction (qPCR) for P. ichikawai. In the aquarium experiment, we demonstrated that the addition of benzalkonium chloride (BAC), a reagent that inhibits eDNA degradation, was effective for water sample storage. In the field, eDNA has consistently been detected at sites where P. ichikawai has been confirmed. There was no difference in eDNA concentration between the water samples taken at different sampling times or between those taken from pools and riffles in the rivers. This result provides evidence that researchers can collect water samples during the daytime, which would reduce the risk of water accidents (e.g., drowning or submerged in darkness) associated with field eDNA surveys of nocturnal species, such as P. ichikawai. Furthermore, we propose that researchers perform on-site surveys for collecting water samples without considering the microhabitat preferences of the target species (e.g., riffle/pool). We recommend that water samples be treated with BAC immediately after collection in the field and then stored in low-temperature conditions. The cooling procedure with BAC outlined here can be advantageous in collecting samples from many sites in a short time, because it only requires the collection of water in the field. [ABSTRACT FROM AUTHOR]

Cataract surgery can cause dry eye symptoms. One of the many factors compromising the ocular surface is the use of benzalkonium chloride (BAC)-preserved topical eye drops administered during the postoperative period. In this open-label, prospective, randomized, comparative clinical trial, 40 patients not previously affected by dry eye disease were assigned to receive either preservative-free (PFD) or preserved (PD) dexamethasone 0.1% eye drops for two weeks after a standard phacoemulsification procedure. Fluorescein break-up time, ocular surface staining score, Schirmer test, Ocular Surface Disease Index and anterior chamber (AC) cells were evaluated at baseline prior to the surgery and 2 weeks after surgery. No statistically significant differences in baseline assessments were observed between groups. At week 2, a significant increase in corneal staining scores (p = 0.003) and foreign body sensation (p = 0.04) was observed for the PD group only. The conjunctival staining score was significantly higher in both groups. The mean AC cell grading was higher in the PFD group than in the PD group (0.28 ± 0.30 and 0.07 ± 0.18, respectively; p = 0.013). Preservative-free dexamethasone eye drops after cataract surgery caused milder dry eye symptoms as compared with preserved dexamethasone. The AC inflammation control comparison may require a larger study group. Trial registration: ClinicalTrials.gov identifier NCT05753787, 03/03/2023. [ABSTRACT FROM AUTHOR]

Plasticizers are additives used to ensure flexibility to polymer blends and thereby to increase their processability. As the typical plastic component phthalates and other fossil-based components contribute environmental issues since such compounds are not biodegradable. To overcome these problems, researchers began to focus on biodegradable thermoplastics and plasticizers. Plasticizers is a highly branched polysaccharide stored in plants as an alternative to currently used non-biodegradable plasticizing compounds. In the light of this, the present study has experienced a novel bio-plasticizer from Pedalium murex (PM), a medicinal plant and analyzed its plasticizing effects using number of characterization studies as density, FT-IR, XRD, TGA, AFM, SEM, etc. It is found that the material is thermally stable up to 262 °C and possess good surface roughness of 31.804 nm, which are the required features for composite or bio-filmmaking. The final residue of the PM plasticizers during TGA is about 51.48%, showing the existence of silica that accomplish desired mechanical and thermal properties. Although, the PM plasticizers have good CI and CS values of 6.5% and 460.3 nm, respectively. On the other hand, FT-IR analysis demonstrated that amylose and amylopectin have a broad band at 3326 cm−1, where amylose predominates in the amorphous regions while amylopectin predominates in the crystalline zones. The PLA/1.0% PM plasticizer film exhibited high tensile strength, tensile modulus, and slightly low elongation % of 22.21 MPa, 12.29 MPa and 22.74%. The present study accomplished that the obtained bio-plasticizers hold good plasticizing effect, compatible and biodegradable nature. Since plasticizing samples were created utilizing natural and environmentally safe raw materials, which makes them an excellent alternative to traditional non-biodegradable plasticizers. [ABSTRACT FROM AUTHOR]

Three smart carbon paste electrodes were fabricated to quantify dorzolamide hydrochloride DRZ, including conventional carbon paste I, modified carbon paste embedding Silica II, and modified carbon paste embedding β-cyclodextrin III. This study is based on the insertion of DRZ with phosphomolybdic acid to create an electroactive moiety dorzolamide-phosphomolybdate ion exchanger using a solvent mediator dibutyl phthalate. The three constructed carbon paste electrodes displayed Nernstian responses and linear concentration ranges with lower detection limits. The vital performance of the created electrodes was verified in relation to various parameters. The electrodes enhance the selective determination of DRZ in the presence of inorganic ions, a co-formulated drug in the dosage form timolol maleate, and the excipient benzalkonium chloride. The modified carbon paste electrode including Silica was utilized to detect DRZ in ophthalmic eye drop form utilizing the direct calibration curve and potentiometric titration methods. Satisfactory findings were achieved by comparing them to other reported methods. [ABSTRACT FROM AUTHOR]

Antimicrobial resistance is one of the leading concerns in medical care. Here we study the mechanism of action of an antimicrobial cationic tripeptide, AMC-109, by combining high speed-atomic force microscopy, molecular dynamics, fluorescence assays, and lipidomic analysis. We show that AMC-109 activity on negatively charged membranes derived from Staphylococcus aureus consists of two crucial steps. First, AMC-109 self-assembles into stable aggregates consisting of a hydrophobic core and a cationic surface, with specificity for negatively charged membranes. Second, upon incorporation into the membrane, individual peptides insert into the outer monolayer, affecting lateral membrane organization and dissolving membrane nanodomains, without forming pores. We propose that membrane domain dissolution triggered by AMC-109 may affect crucial functions such as protein sorting and cell wall synthesis. Our results indicate that the AMC-109 mode of action resembles that of the disinfectant benzalkonium chloride (BAK), but with enhanced selectivity for bacterial membranes. The mechanism of action of the antibacterial tripeptide AMC-109 is unclear. Here, Melcrová et al. show that AMC-109 self-assembles into stable aggregates with a cationic surface, and then individual peptides insert into the bacterial membrane and disrupt membrane nanodomains, thus affecting membrane function without forming pores. [ABSTRACT FROM AUTHOR]

Microplastics and benzyldimethyldodecylammonioum chloride (DDBAC) enter the environment more frequently during the COVID-19 pandemic and their co-occurrence will be a potential threat to the environment in the post-pandemic era. This study investigates the performance of an electrochemical system for the simultaneous removal of microplastics and DDBAC. During experimental studies, effects of applied voltage (3–15 V), pH (4–10), time (0–80 min), electrolyte concentration (0.01–0.0.09 M), electrode configuration, and perforated anode were investigated to identify their influence on DDBAC and microplastics removal efficiency. Eventually, the techno-economic optimization yielded to evaluate the commercial feasibility of this process. The central composite design (CCD) and analysis of variance (ANOVA) are employed for evaluation and optimization of the variables and response, DDBAC-microplastics removal, and for determining the adequacy and significance of mathematical models proposed by response surface methodology (RSM). Experimental results indicate that optimum conditions are pH = 7.4, time = 80 min, electrolyte concentration = 0.05 M, and applied voltage = 12.59, in which the removal of microplastics, DDBAC, and TOC reached the maximum level, which was 82.50%, 90.35%, and 83.60% respectively. The results confirm that the valid model is adequately significant for the target response. Overall, financial and energy consumption analyses confirmed that this process is a promising technology as a commercial method for the removal of DDBAC-microplastics complexes in water and wastewater treatment. [ABSTRACT FROM AUTHOR]

Phytophthora cinnamomi is an oomycete found in the soil and capable of invading the roots of a wide range of host plants globally, potentially killing them and affecting the ecosystems they inhabit. This pathogen is often inadvertently dispersed in natural vegetation on the footwear of humans. A range of equipment is often provided or recommended to be carried for cleaning footwear in places where P. cinnamomi poses a threat to biodiversity. These are typically a brush for mechanically removing soil and/or a disinfectant for killing the pathogen. Despite their widespread use, to our knowledge, the majority of hygiene measures have not been experimentally tested for their efficacy. In the current study, we tested whether two types of brush and the two most widely used disinfectants (70% methylated spirits and benzalkonium chloride) were effective in removing the pathogen from boots. We tested the brushes and disinfectants in two soil types and two moisture levels. All hygiene measures were found to be better than doing nothing, although some were only effective with sandy or dry soils. Benzalkonium chloride was largely ineffective as a spray but highly effective when used in a footbath. Brushing did not improve cleaning when used with 70% methylated spirits. None of the hygiene measures was completely effective for cleaning boots that had been in wet loamy soil. Our findings have important implications for management of this threat because some recommended hygiene practices are not doing what they claim. [ABSTRACT FROM AUTHOR]

Benzalkonium salts are widely used in the composition of antimicrobial preparations in industry and everyday life and as algaecides to treat pool water. The disinfection of tap or waste water with active chlorine in the presence of natural or anthropogenic bromide anions or using bromine as a pool water disinfectant creates conditions for the interaction of benzalkonium cations with active bromine to form disinfection by-products. This study presents the results of a model benzalkonium bromination with the identification of the resulting products by high-performance liquid and gas chromatography combined with high-resolution mass spectrometry. The primary transformation products are monobromo derivatives formed by the radical substitution of hydrogen atoms of the alkyl chain with bromine. Their further transformations yield dibromo-, hydroxy-, and hydroxybromo derivatives. The final products of the deep degradation of benzalkonium are bromoform, bromoacetonitrile, and several brominated hydrocarbons. [ABSTRACT FROM AUTHOR]

This study evaluates the effectiveness of objective techniques in assessing dry eye disease (DED) treatment compared with the subjective assessment commonly used in clinical practice. Thirty subjects were recruited for two visits separated by 28(± 3) days of treatment with artificial tears. A buttery of common subjective assessment methods were accompanied by a set of objective techniques including measurement of noninvasive tear film break-up time (NIBUT), lipid layer thickness (LLT), and quantitative evaluation of tear film surface quality and dynamics (TFD). Additionally, meibography was performed. Two commercially available videokeratoscopes and a prototype of a lateral shearing interferometer were used for the measurements. Both subjective and objective techniques showed a positive effect of artificial tears in DED treatment. Statistically significant improvements were observed in subjective symptoms (from P < 0.001 for Ocular Surface Disease Index, OSDI to p = 0.019 for tearing), conjunctival redness (P = 0.022), ocular staining (P = 0.012), fluorescein tear film break-up time (P = 0.015), NIBUT (P = 0.037), LLT (P < 0.001), and TFD (P = 0.048). In general, weak or statistically insignificant correlations were observed between subjective and objective assessment methods. The apparent lack of correlation between these methods might indicate the complementary character of objective techniques that likely assess other characteristics of ocular surface health than those assessed subjectively. [ABSTRACT FROM AUTHOR]

The intact population of Sertoli cells is crucial for the maintenance of male germ cell development. At sexual maturity, Sertoli cells of most mammals lose their ability to proliferate and to restore their population after damage. Thus, a search for alternative sources of Sertoli cells suitable for transplantation is an important goal. Sertoli-like cells (SLCs) from the adult rete testis might become such a source because they express many Sertoli cell marker genes but are capable of proliferation in vitro. We have already shown earlier that SLCs participated in the formation of tubule-like structures when co-cultured with neonatal Sertoli cells. In the current study, we tested SLC properties in vivo. We carried out transplantations of cultured SLCs into mouse testes treated with a detergent benzalkonium chloride (BC), which was used for depleting Sertoli cells from testes earlier. Indeed, BC injections via the rete testis reduced the number of Sertoli cells. It was also demonstrated that donor SLCs settled in at basement membranes of damaged host seminiferous tubules and form epithelial structures. They retain their viability, proliferative capacity, and expression of marker genes for at least 4 weeks. [ABSTRACT FROM AUTHOR]

A library of 31 mono- and bis-quaternary ammonium compounds based on 3-hydroxypyridine was synthesized. Primary screening of their antibacterial activity in vitro in six archival strains of bacteria revealed four highly active lead compounds surpassing commercial antiseptics benzalkonium chloride, miramistin, and chlorhexidine in their activity. Further in-depth study of the antibacterial activity of the lead compounds in vitro in 16 clinical bacterial strains and the study of their toxicity in vitro and in vivo showed that 2,6-bis(N,N-dimethyl-N-dodecylammoniomethyl)-3-methoxypyridine dichloride was the most active and least toxic and manifested a higher activity in comparison with benzalkonium chloride, miramistin, and chlorhexidine in clinical isolate of both gram-positive and gram-negative bacteria, as well as a moderate toxicity in vivo (LD50 = 82 6 mg kg−1, mice, oral administration). The quaternary ammonium compounds based on 3-hydroxypyridine are of undoubted interest for the further development of antibacterial drugs. [ABSTRACT FROM AUTHOR]

TONS504 (C51H58N8O5I2), a chlorine derivative, effectively generates singlet oxygen by light activation and exhibits photodynamic antimicrobial effects (PAEs) on various pathogens. However, this photosensitizer has some limitations: a high tendency to self-aggregate and a relatively weak PAE for Gram-negative bacteria compared with Gram-positive bacteria. To overcome these limitations, the present study investigated the synergistic effects of the PAE of TONS504 and two additives commonly contained in ophthalmic solutions: benzalkonium chloride (BAC) or ethylenediaminetetraacetic acid (EDTA). Staphylococcus aureus and Pseudomonas aeruginosa were exposed to TONS504 and/or each additive. Photodynamic antimicrobial chemotherapy was performed with light irradiation centered at a wavelength of 665 nm with a total light energy of 30 J/cm2. Following incubation, the number of colonies formed was counted. Additionally, we examined the inhibitory effects of the additives on TONS504 self-aggregation by observing its absorption spectrum. Consequently, the PAEs of TONS504 on S. aureus were enhanced by both additives, and BAC displayed stronger synergistic effects on the bacteria than EDTA. By contrast, only EDTA increased the PAE on P. aeruginosa. The peak of the TONS504 absorption spectrum shifted to a longer wave length and the absorbance increased in the presence of BAC, suggesting that BAC inhibited the self-aggregation of the photosensitizer. In conclusion, the combination of BAC or EDTA and TONS504-mediated photodynamic antimicrobial chemotherapy exhibits a synergistic antimicrobial effect on S. aureus and P. aeruginosa. The optimal additive to enhance the PAE may differ between bacterial strains. [ABSTRACT FROM AUTHOR]

Topical anti-glaucomatous medications are still the most important measure to lower intraocular pressure. Large number of studies have confirmed that long-term use of anti-glaucomatous eye drops, especially containing benzalkonium chloride, a preservative, can cause or aggravate ocular surface injury. Ocular surface diseases damage the ocular microenvironmental health status, reduce the patients' compliance with the treatment, and finally affect the treatment result. Therefore, the ocular surface management of patients with glaucoma is very important. This includes the selection of drugs that are better tolerated according to individual conditions, preservative-free formulations, drugs that protect against ocular surface disease, or selecting surgery and laser treatment, to prevent the damage to the ocular surface by topical anti-glaucomatous drugs. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate any alterations in the tear film and ocular surface beyond the early postoperative period following penetrating keratoplasty (PK) and deep anterior lamellar keratoplasty (DALK). This cross-sectional, contralateral-eye study compared ocular surface and tear film parameters of eyes with a previous PK or DALK in one eye and no prior surgery in the contralateral eye. Overall, 14 (87.5%) participants underwent PK, and 2 (12.5%) underwent DALK using a mechanical dissection. The median time from surgery was 3.4 years (range 1.5 to 38.7 years). The indication for unilateral keratoplasty was keratoconus in 15 (94%) participants, and corneal scarring in 1 (6%) eye, secondary to microbial keratitis. Operated eyes exhibited poorer non-invasive tear film breakup time, lower corneal sensitivity, lower sub-basal nerve density and more severe fluorescein staining scores than unoperated fellow eyes (all Q < 0.05). There were no significant differences in tear film lipid layer quality, tear meniscus height, conjunctival hyperaemia, lissamine green staining score, or meibography grade between operated and fellow eyes (all Q ≥ 0.20). Higher corneal esthesiometry threshold (lower corneal sensitivity) was correlated with shorter non-invasive tear film breakup time (Spearman's rho = − 0.361, p = 0.04) and increased fluorescein staining score (Spearman's rho = 0.417, p = 0.02). Keratoplasty can induce persistent changes in the ocular surface and tear film, including: increased fluorescein staining, decreased tear film breakup time, decreased corneal sub-basal nerve plexus density, and reduced corneal sensitivity. [ABSTRACT FROM AUTHOR]

Triploid lacquer trees have a higher yield of raw lacquer and greater stress resistance; however, it is challenging to develop efficient and rapid seedling culture techniques because of the influence of metabolites with raw lacquer. In this study, the stem segments of a triploid lacquer tree were used to investigate the effects of explant sterilization treatment, different combinations of exogenous hormone concentrations on the induction of axillary buds, seedling development, and rooting, as well as transplanting substrate ratios. The results showed that the optimal combination of disinfection treatment for triploid Toxicodendron vernicifluum (Stokes) F. A. Barkl explants involves 75% alcohol immersion for 10 s, followed by 2.0% benzalkonium chloride treatment for 1 min and 0.1% HgCl2 treatment for 4 min. The suitable medium for axillary bud induction was Murashige and Skoog (MS) containing 0.1 mg•L−1 zeatin (ZT) and 0.1 mg•L−1 6-benzylaminopurine (6-BA), resulting in a high induction rate of 95.0%. Use of 1/2 MS supplemented with 0.5 mg•L−1 6-BA and 0.3 mg•L−1 2,4-dichlorophenoxyacetic acid (2,4-D) was the most effective for axillary bud proliferation. The combination of 1/2 MS containing 0.1 mg•L−1 6-BA, 0.5 mg•L−1 2,4-D, 0.5 mg•L−1 indole-3-butyric acid (IBA), and 0.2% activated carbon (AC) was an optimum for hardening-off. With woody plant medium (WPM) supplemented with 0.5 mg•L−1 naphthaleneacetic acid (NAA) and 0.5 mg•L−1 2,4-D and 0.5 g•L−1 AC as a rooting medium, the rooting rate was 67.8%. Also, the appropriate transplanting substrate ratio for triploid Toxicodendron vernicifluum (Stokes) F. A. Barkl was grass charcoal:laterite:humus = 1:1:1. Collectively, the results provided the technical assurance for seedling scale multiplication and propagation, facilitating its application in production. [ABSTRACT FROM AUTHOR]

Background: Benzalkonium chloride (BAK), the most commonly used preservative in anti-glaucoma eye drops, inflicts damage to the ocular surface. A novel anti-glaucoma formulation that avoids the use of BAK has been developed. The aim of this study was to evaluate the cytotoxicity of this formulation and to compare it with an ophthalmic solution containing BAK. Methods: Two different latanoprost eye drops were used: one ophthalmic solution (LSc) containing BAK 0.02% and one ophthalmic nanoemulsion (LNe) with a soft preservative (potassium sorbate 0.18%). Human epithelial conjunctival cells were incubated for 15, 30, and 60 min with either LSc or LNe. The cytotoxicity was determined by MTT assay. Cell death was measured by flow cytometry using annexin V–FITC and propidium iodide. Results: The values of cell viability and proliferation obtained from cells exposed to LNe were between 80 and 90% relative to the control group, whereas values obtained from cells exposed to LSc were around 30% at all study times (p < 0.05 at 15 and 30 min; p < 0.01 at 60 min). The percentage of viable cells decreased significantly when cells were incubated with LSc compared with cells incubated with LNe at all the study times, while the percentage of cells in late apoptosis/necrosis increased significantly in cells exposed to LSc compared to LNe. Conclusions: The new latanoprost nanoemulsion is significantly less cytotoxic on human conjunctival cells than LSc. These results suggest that the new formulation might be gentler on the eye surface than currently available BAK-preserved latanoprost solutions. [ABSTRACT FROM AUTHOR]

Cytotoxicity testing is a regulatory requirement for safety testing of new ocular implants. In vitro toxicity tests determine whether toxic chemicals are present on a material surface or leach out of the material matrix. A method of evaluating the cytotoxicity of ocular implants was developed using fluorescent viability dyes. To assess the assay's sensitivity in detecting toxic substances on biomaterials, zinc diethydithiocarbamate (ZDEC) and benzalkonium chloride (BAK) were deposited on silicone surfaces at different concentrations. Human lens epithelial cells (HLEC) were added to the surface of these treated silicone surfaces and were assessed for viability. The viability of both the adherent and non-adherent cells was determined using confocal microscopy with, annexin V, ethidium homodimer, and calcein. Cell metabolism was also evaluated using resazurin and the release of inflammatory cytokines was quantified using a multiplex Mesoscale Discovery platform. Confocal microscopy was shown to be a sensitive assay for evaluating material toxicity, as significant toxicity (p < 0.05) from ZDEC and BAK-treated surfaces compared to the untreated silicone control was detected. Patterns of cytokine release from cells varied depending on the toxin evaluated and the toxin concentration and did not directly correlate with the reduction in cell metabolic activity measured by alamarBlue. [ABSTRACT FROM AUTHOR]

Background: Biocides are frequently used as preservative, disinfectant and sterilizer against many microorganisms in hospitals, industry and home. However, the reduced susceptibility rate of Pseudomonas aeruginosa (P. aeruginosa) strains to biocides is increasing. The aim of this study was to evaluate the antimicrobial activity of four frequently used biocides against P. aeruginosa and to determine the prevalence of genes involved in biocide resistance. Methods: A total of 76 clinical isolates of P. aeruginosa strains were used in the present study. The minimum inhibitory concentrations (MICs) of four biocides, i.e. chlorhexidine digluconate, benzalkonium chloride, triclosan and formaldehyde, against P. aeruginosa strains were determined using agar dilution method. In addition, the prevalence of biocide resistance genes was determined using the polymerase chain reaction (PCR) method. Results: In the present study, the highest MIC90 and MIC95 (epidemiological cut-off) values were observed for benzalkonium chloride (1024 μg/mL), followed by formaldehyde (512 μg/mL), triclosan (512 μg/mL) and chlorhexidine digluconate (64 μg/mL). Furthermore, the prevalence of qacEΔ1, qacE, qacG, fabV, cepA and fabI genes were 73.7% (n = 56), 26.3% (n = 20), 11.8% (n = 9), 84.2% (n = 64), 81.5% (n = 62) and 0% (n = 0), respectively. A significant association was observed between the presence of biocide resistance genes and MICs (p < 0.05). Furthermore, there was no significant association between the presence of biocide resistance genes and antibiotic resistance (p > 0.05), except for levofloxacin and norfloxacin antibiotics and qacE and qacG genes (p < 0.05). Conclusion: Our results revealed that chlorhexidine digluconate is the most effective biocide against P. aeruginosa isolates in Ardabil hospitals. However, we recommend continuous monitoring of the antimicrobial activity of biocides and the prevalence of biocide-associated resistance genes for a better prevention of microorganism dissemination and infection control in hospitals. [ABSTRACT FROM AUTHOR]

In the biomonitoring using environmental DNA (eDNA) analysis, the suppression of eDNA degradation has been an important issue to estimate accurately the presence of target species and their eDNA concentrations. A recently proposed eDNA preservation technique requires only the addition of benzalkonium chloride (BAC) to water samples and has been used for various studies as an alternative solution to on-site filtration. However, BAC remaining in filters may adsorb to and inhibit the function of the enzyme used to extract eDNA from filters. In this study, we tested whether eDNA yield is affected by BAC addition immediately before filtration and demonstrated that the BAC in water remaining in filters decreased the eDNA yield significantly. We found that simple pre-centrifugation is effective for removing the remaining water from the filters to prevent the eDNA yield reduction due to the use of BAC. This is the most important finding in the present study. Appropriate eDNA extraction techniques are needed when BAC is used to secure eDNA yields and expand the application of eDNA analysis for biomonitoring. [ABSTRACT FROM AUTHOR]

Biocides used as disinfectants are important to prevent the transmission of pathogens, especially during the current antibiotic resistance crisis. This crisis is exacerbated by phenotypically tolerant persister subpopulations that can survive transient antibiotic treatment and facilitate resistance evolution. Here, we show that E. coli displays persistence against a widely used disinfectant, benzalkonium chloride (BAC). Periodic, persister-mediated failure of disinfection rapidly selects for BAC tolerance, which is associated with reduced cell surface charge and mutations in the lpxM locus, encoding an enzyme for lipid A biosynthesis. Moreover, the fitness cost incurred by BAC tolerance turns into a fitness benefit in the presence of antibiotics, suggesting a selective advantage of BAC-tolerant mutants in antibiotic environments. Our findings highlight the links between persistence to disinfectants and resistance evolution to antimicrobials. Phenotypically tolerant, persister bacterial subpopulations can survive transient antibiotic treatment and facilitate resistance evolution. Here, Nordholt et al. show that E. coli can display persistence against a widely used disinfectant and this is associated with alterations in the cell surface and with antibiotic tolerance. [ABSTRACT FROM AUTHOR]

This study aimed to achieve an in vitro quantification of the effects of composition and formulation factors on the killing rates of alcohol-based hand sanitizers. The killing rates of 85% ethyl alcohol (ET) and isopropyl alcohol (IPA) were studied under different conditions such as pH, electrolyte concentration, or inclusion of herbal extracts (cucumber, carrot, and aloe vera), a quaternary ammonium compound, or thickener over different time intervals. Changes in the activities were retested after 3 months as an indication of stability. From two-way ANOVA, both the time of exposure and the sanitizer type affected the activity against Staphylococcus aureus (P = 0.001 for both alcohols), whereas for Escherichia coli, time of exposure was significant (P = 0.027), while sanitizer type was less significant (P = 0.063). Extreme pHs, the presence of ions, and the inclusion of additives such as benzalkonium chloride (BAC), plant extracts, or carbomer impacted the 3-month activity of the samples differently. Important differences existing in the activities of ET and IPA, as a function of formulation factors or use conditions have been quantified using in vitro methods. Formulations should best be tailored for particular purposes and the all-purpose hand sanitizer may not exist. [ABSTRACT FROM AUTHOR]

The present study demonstrated the protective effects of low-molecular-weight adipose-derived stem cell-conditioned medium (LADSC-CM) in a mouse model of dry eye syndrome. Mice subjected to desiccating stress and benzalkonium chloride had decreased tear secretion, impaired corneal epithelial tight junction with microvilli, and decreased conjunctival goblet cells. Topical application of adipose-derived stem cell-conditioned medium (ADSC-CM) stimulated lacrimal tear secretion, preserved tight junction and microvilli of the corneal epithelium, and increased the density of goblet cells and MUC16 expression in the conjunctiva. The low-molecular-weight fractions (< 10 kDa and < 3 kDa) of ADSC-CM (LADSC-CM) provided better protections than the > 10 kDa or > 3 kDa fractions of ADSC-CM. In the in vitro study, desiccation for 10 min or hyperosmolarity (490 osmols) for 24 h caused decreased viability of human corneal epithelial cells, which were reversed by LADSC-CM. The active ingredients in the LADSC-CM were lipophobic and stable after heating and lyophilization. Our study demonstrated that LADSC-CM had beneficial effects on experimental dry eye. It is worthy of further exploration for the active ingredient(s) and the mechanism. [ABSTRACT FROM AUTHOR]

Anti-glaucoma agents-induced corneal toxicity may be misdiagnosed as herpetic simplex keratitis (HSK). In our study, nineteen glaucoma patients were presumed to have HSK before referral. Corneal lesions were classified into (I) linear pseudodendritic lesions formed by elevated opacified cells, (II) linear pseudodendritic lesions formed by grouped superficial punctate keratitis (SPK), (III) satellite full-thickness epithelial defects, (IV) satellite lesions formed by elevated opacified cells, and (V) geographic lesions formed by grouped SPK. We observed thirty-one events, with 15 in the lower and 16 in the central corneas. There were 21 (67.7%) type II, five (16.1%) type V, two (6.5%) of each for types III and IV, and one (3.2%) type I events. Among linear lesions (types I and II), 17 (77.3%) had horizontal and 5 (22.7%) had curvilinear orientations. Exposure duration to the last-added anti-glaucoma agent was three days to 14.5 years. About half of the events (16/31, 51.6%) used prostaglandin analogues, and 30/31 (96.8%) applied benzalkonium chloride (BAK)-containing agents. All lesions resolved within two months after decreasing offending medications or enhancing protection of ocular surface. In conclusion, anti-glaucoma agents-induced pseudodendritic keratitis presents majorly in central-lower cornea as horizontally linear lesions, and BAK-containing agents are observed in the most events. [ABSTRACT FROM AUTHOR]

Background: To compare the effect of two different prostaglandin analogues (Travatan® vs. Xalatan®) on ocular surface parameters. Methods: This study includes 44 eyes of 44 patients with newly diagnosed primary open-angle glaucoma (POAG) or ocular hypertension (OHT). Patients were randomly divided into two groups and treated with either benzalkonium chloride (BAK)-preserved latanoprost and polyquad-preserved travoprost. Changes in intraocular pressure (IOP) levels and ocular surface parameters including ocular surface disease index (OSDI) questionnaire, tear breakup time (TBUT), ocular surface staining scores, and Schirmer test scores of patients were performed at baseline, 1, 3, 6, and 12 months of treatment and compared. Results: The age, sex ratio, visual acuity, central corneal thickness, and cup/disc ratio were similar between the groups. A decrease in IOP levels (23.3 ± 2.5 to 15.5 ± 2.3), TBUT (5.5 ± 2.3 to 4.1 ± 1.7 s), Schirmer test values (11.3 ± 5.9 to 8.6 ± 4.7 s), and a worsening in OSDI scores (44.6 ± 15.2 to 55.1 ± 13.1) and staining scores (1.7 ± 1.6 to 2.3 ± 1.8) were observed in all patients in the first month of treatment (p < 0.05, for all). No further worsening was detected during the 1-year follow-up. There was no difference between the groups in terms of alterations in IOP levels and ocular surface parameters. Conclusion: Travatan® and Xalatan® have a similar effect on IOP levels and ocular surface parameters in patients with POAG and OHT. [ABSTRACT FROM AUTHOR]

Background: Acinetobacter baumannii (A. baumannii) is among the important causes of nosocomial infections. Due to the emergence of antibiotic resistance, many problems have been raised in the successful treatment of patients infected by this bacterium with the subsequent mortality. Therefore, the present study was performed to evaluate the antibacterial effect of Octenicept (OCT), and Benzalkonium chloride (BZK) against A. baumannii strains isolated from clinical samples, and to determine the genetic diversity of strains by RAPD-PCR method. Methods: A total of 119 A. baumannii isolates were collected and confirmed by conventional culture and biochemical tests and PCR assay. Susceptibility of the isolates to antibiotics was evaluated by standard antibiotic susceptibility testing (AST). For antiseptics OCT and BZK, Minimum inhibitory concentration (MIC) was assessed by broth microdilution method. The prevalence of qacE and qacΔE1 genes related to antiseptics was estimated by PCR assay. Finally, genetic diversity of strains was determined by using RAPD-PCR. Results: All 119 suspected isolates were confirmed as A. baumannii using conventional microbiologic tests and PCR assay. The isolates were mostly originated from blood samples. In AST, the lowest resistance was seen for ciprofloxacin and gentamicin. For antiseptics, the MIC values were reported as 15.26 μg/ml for OCT and 640 μg/ml for BZK. The antiseptic genes of qacE and qacΔE1 were found to be present in 56 (47.05%) and 59 (49.57%) of isolates respectively. RAPD typing revealed great diversity among A. baumannii isolates, with 37 clusters in isolates from ICU, of which 32 clusters were single and 5 were multiple. Conclusions: Considering the increase of resistance to antiseptics, it is of importance to monitor the susceptibility of A. baumannii to antiseptics and to promote antiseptic stewardship in hospitals. Furthermore, in this study great diversity was observed among A. baumannii isolates, which is important in understanding the molecular epidemiology of the outbreaks caused by this organism in the hospitals. [ABSTRACT FROM AUTHOR]

Previous studies have shown that benzoylaconine (BAC), a representative monoester alkaloid, has a potential anti-inflammatory effect. This study investigated the underlying molecular mechanisms using the mode of LPS-activated RAW264.7 macrophage cells. Our findings showed that BAC significantly suppressed the release of pro-inflammatory cytokines and mediators, including IL-6, TNF-α, IL-1β, ROS, NO, and PGE2. BAC treatment also effectively downregulated the elevated protein levels of iNOS and COX-2 induced by LPS in a dose-dependent manner. In this study, we found that BAC inhibited LPS-induced NF-κB activation by reducing the phosphorylation and degradation of IκBα by western blotting and blocking the nuclear translocation of p65 using an immunofluorescence assay. The elevated protein levels of JNK, p38, and ERK phosphorylation after LPS stimulation were restored effectively by BAC treatment. The protein expression of Toll-like receptor 4 (TLR4) and LPS-induced phosphorylation of TAK1, which is a crucial upstream regulatory factor of TLR-induced MAPK and NF-κB signaling, were inhibited by BAC in activated RAW264.7 macrophages. Moreover, BAC decreased the levels of TAK1 phosphorylation and pro-inflammatory cytokines and mediators associated with MAPK and NF-κB activation, similar to TLR4 inhibitor TAK-242. These findings demonstrated that BAC exhibited an anti-inflammatory effect by the inhibition of TLR-induced MAPK and NF-κB pathways, indicating that it could potentially be used for treating inflammatory diseases. [ABSTRACT FROM AUTHOR]

This study assessed the clinical risk factors for periorbital dermatitis (PD) after using dorzolamide/timolol eye drops in a total of 1282 glaucoma patients. Both the PD(+) group and the PD(−) group were evaluated using clinical data such as age, sex, dosing duration, presence of benzalkonium chloride (BAK) in the formulation, ocular surgery history (e.g. cataract or glaucoma operations), height, weight, personal history of systemic hypertension, smoking, alcohol consumption, intraocular pressure, best-corrected visual acuity (BCVA), central corneal thickness, axial length, and visual field index (VFI). Univariate analyses showed that shorter dosing duration, higher rate of BAK-included cases, worse BCVA, worse VFI, more systemic hypertension history, and more ocular surgery history were more associated with the PD(+) group than the PD(−) group. The BAK(−) group showed a lower PD rate than the BAK-included group, which was supported by the Kaplan–Meier analysis (log-rank test, p = 0.0014). Multivariate analyses revealed that the probability of PD increased by 8 times if they had a history of ocular surgery and increased by 2.3% when the VFI decreased by 1% (Cox's hazard regression test, p < 0.001). Therefore, a preservative-free dorzolamide/timolol can benefit the subjects for those who had ocular surgery or who have worse VFI. [ABSTRACT FROM AUTHOR]

Benzalkonium chloride (BAC) is used as a preservative in eyedrops but induces subconjunctival fibrosis that can result in failure of glaucoma surgery. Tenon's capsule fibroblasts in subconjunctival tissue interact with the corneal epithelium through tear fluid. With the use of a coculture system, we have now investigated the effect of human corneal epithelial (HCE) cells on myofibroblastic transdifferentiation of human Tenon fibroblasts (HTFs) induced by BAC (5 × 10−6%). Immunofluorescence and immunoblot analyses revealed that the BAC-induced expression of α smooth muscle actin (αSMA) in HTFs was suppressed by coculture of these cells with HCE cells (p < 0.01). The concentration of interleukin-10 (IL-10) in culture supernatants of BAC-treated HTFs was increased by coculture with HCE cells (17.26-fold, vs. coculure, p < 0.001). Immunofluorescence and immunoblot analyses also showed that exogenous IL-10 (300 pg/ml) suppressed the BAC-induced expression of αSMA by 43.65% (p < 0.05) as well as the nuclear translocation of myocardin-related transcription factor-A (MRTF-A) by 39.32% (p < 0.01) in HTFs cultured alone. Our findings suggest that corneal epithelial cells may protect against subconjunctival fibrosis by maintaining IL-10 levels and preventing the MRTF-A-dependent transdifferentiation of HTFs into myofibroblasts. [ABSTRACT FROM AUTHOR]

Purpose: To prospectively evaluate the effect of benzalkonium chloride (BAK)-preserved latanoprost on ocular surface damage and identify the associated risk factors among treatment-naive glaucoma patients. Methods: The basal Schirmer's test results, corneal Oxford staining score, non-invasive keratograph tear-breakup time, oculus hyperemia index score (objective metrics), and ocular surface disease index (OSDI) questionnaire (subjective metric) were evaluated at baseline, 1 month, and 4 months after receiving latanoprost eye drops. Associated risk factors were assessed by multivariate linear regression. Results: Seventy-four eyes (44 patients) were enrolled. Basal Schirmer's test tear-flow and Oxford scores gradually deteriorated (β = −0.14, P = 0.001 and β = 0.1, P < 0.001, respectively). The percentage of unstable tear-film (breakup time < 10 s) increased significantly at 4 months (6.21% vs 9.11%, P = 0.042). Hyperemic scores increased significantly at 1 month and normalized at 4 months (P = 0.01 and P = 0.16, respectively); total OSDI scores tended to improve (β = −0.76, P = 0.06). Older age was associated with additional corneal Oxford staining (P = 0.005); female sex was associated with increased unstable tear-film scores (P = 0.01). Artificial tear use was associated with a smaller decrease in basal Schirmer's test values (P = 0.01) and a smaller increase in unstable tear-film scores (P = 0.02). Conclusions: Preserved latanoprost eye drops affected ocular surface changes in glaucoma patients through decreased basal tear secretion. Artificial tears represent an early intervention in vulnerable glaucoma patients with reduced tear secretion and impaired tear-film stability. [ABSTRACT FROM AUTHOR]

In agreement with the recent trend of consumers' demand for natural antimicrobial products, the importance of using natural compounds in food is increasing. Among numerous natural compounds, grapefruit seed extract (GSE) is widely known for its extremely effective antimicrobial activity. The direct use of GSE in food is the most common method of application. Other GSE applications exist using it with coating materials and incorporating it into edible films. Previously done studies identified benzalkonium chloride, benzethonium chloride, and other synthetic agents from GSE. Unfortunately, the presence of these antibacterial contents does not exactly coincide with the natural aspects of GSE. Even though GSE is identified as a natural antimicrobial, this observation suggests that the GSE antibacterial activity is derived from these synthetic substances such as benzalkonium chloride. Therefore, further research is needed about these controversial issues. This review analyzed the application of GSE as a natural antimicrobial in the food industry and suggested further research directions. [ABSTRACT FROM AUTHOR]

To investigate the effect of benzalkonium chloride (BAC) addition to ethylenediaminetetraacetic acid (EDTA) on transforming growth factor-β1 (TGF-β1) release, as well as attachment and proliferation of dental pulp stem cells (DPSCs) on dentin. A total of standard 268 human dentin disks were prepared and immersed in 1.5% sodium hypochlorite (NaOCl) for 5 min. The disks were rinsed with distilled water and randomly divided into seven groups. In control group, the disks received no further treatment. The remaining disks were immersed in following solutions: 17% EDTA or 17% EDTA + 0.008% BAC for 1, 5 or 10 min and rinsed with distilled water. DPSCs were seeded in part of the disks since the TGF-β1 release assay was performed with disks with and without cells. The attachment and proliferation of DPSCs on dentin disks were analyzed using lactate dehydrogenase activity and WST-1 assays, respectively. The cell morphology was observed by scanning electron microscopy. The release of TGF-β1 was quantified using ELISA. Data were analyzed using three- and two-way analysis of variance with Bonferroni corrections. Both EDTA solutions increased the attachment and proliferation of DPSCs (p <.05) while there was no significant difference between them (p >.05). The exposure time of both EDTA solutions had no influence on cell attachment, proliferation and TGF-β1 release (p >.05). There was no significant difference in TGF-β1 release between the control and experimental groups (p >.05). The amount of released TGF-β1 from dentin disks was similar whether or not they were seeded with cells (p >.05). Dentin treatment with either of the EDTA solutions had no effect on the amount of TGF-β1 release while both EDTA solutions improved cell attachment and proliferation on dentin surface regardless of exposure time. [ABSTRACT FROM AUTHOR]

The onset of COVID-19 pandemic has suddenly rendered disinfectants an essential class of substances for daily use globally. The demand for different disinfectants has rapidly surged, and it is important that the users of disinfectants are aware of the chemicals present in them, their properties, and how these disinfectants were introduced for public use. The history and development of chlorine-containing disinfectants and their possible modes of action have been explained in this article. The development and current status of hypochlorite-based compounds and chlorinated phenol-based compounds as disinfectants are also discussed in detail. The article explores the pros and cons of having chlorine in disinfectants and also looks critically at the future of such disinfectants based on safety and environmental considerations. [ABSTRACT FROM AUTHOR]

The key clinical attributes of preserved dorzolamide/timolol fixed combination (DTFC) and the emerging potential of preservative-free (PF) DTFC are reviewed with published evidence and clinical experience. The indications and role of DTFC in current glaucoma management are critically discussed. Preserved DTFC became the first intraocular pressure (IOP)-lowering fixed combination (FC) approved by the US Food and Drug Administration (FDA) and remains one of most commonly used medications worldwide. The pharmacological properties of DTFC reflect those of its two time-tested constituents, i.e., the carbonic anhydrase inhibitor dorzolamide and the non-selective beta-blocker timolol. In regulatory studies DTFC lowers IOP on average by 9 mmHg (32.7%) at peak and by 7.7 mmHg (27%) at trough. In trials DTFC shows equivalence to unfixed concomitant therapy, but in real-life practice it may prove superior owing to enhanced convenience, elimination of the washout effect from the second drop, improved tolerability, and better adherence. PF DTFC became the first PF FC approved, first in unit-dose pipettes, and more recently in a multidose format. Cumulative evidence has confirmed that PF DTFC is at least equivalent in efficacy to preserved DTFC and provides a tangible clinical benefit to patients with glaucoma suffering from ocular surface disease by improving tolerability and adherence. Finally, we identify areas that warrant further investigation with preserved and PF DTFC. [ABSTRACT FROM AUTHOR]

The present study aims to examine the in vitro antifungal susceptibility patterns of Candida species isolated from hospital wastewater, and the efficacy of widely used disinfectants (sodium hypochlorite and benzalkonium chloride) against planktonic and biofilm cells were assessed. Susceptibility testing demonstrated that the two azoles were more effective against C. albicans than non-albicans isolates. When we determine the efficiency of disinfectants against the planktonic cells, benzalkonium chloride did not show any activity in all the studied strains under tested conditions except C. albicans-1. However, sodium hypochlorite showed ≥ 4 log10 killing in viable cells for different contact times. On the other hand, while 0.1% and 1% concentrations of benzalkonium chloride showed fungicidal activity against biofilm cells, sodium hypochlorite at 1% only demonstrated fungicidal activity. Those results showed that surface water is a possible transmission path for fungi in the investigated hospital region and may be a health risk, especially for the immunocompromised host. [ABSTRACT FROM AUTHOR]

In recent years, an increasing number of Listeria monocytogenes strains with resistance to quaternary ammonium compounds (QACs) have been reported. However, the genetic basis for QACs resistance in L. monocytogenes remains poorly understood. In the present study, we have characterized the operon lmo0852/lmo0853/lmo0854 (designated sugR/sugE1/sugE2) that contributes to QACs' resistance in L. monocytogenes EGD-e. We constructed the gene deletion mutants and the complemented strains, determined minimum inhibitory concentrations (MICs) of these strains against antimicrobial agents, assessed the transcription levels of target genes by RT-qPCR, and measured the promoter activity by using β-galactosidase assays. We also investigated the interaction between the promoter DNA and the putative regulatory protein by electrophoretic mobility shift assay (EMSA). The sug operon consists of a putative TetR family regulator encoded by sugR and two small multidrug resistance (SMR) efflux pumps encoded by sugE1 and sugE2. Our results showed that either SugE1 or SugE2 is sufficient for QACs' resistance, indicating their function overlapping in QACs' resistance. Interestingly, lacking one sugE gene could lead to a significant increase in transcription of the other sugE gene in the presence of benzalkonium chloride (BC). Additionally, SugR negatively regulates the transcription of the sug locus by binding to the operon promoter. Given that QACs are commonly used in food industry, the findings from this study will help us to have a better understanding of the adaptations of L. monocytogenes to this type of disinfectant. Key points •Either SugE1 or SugE2 was sufficient for QACs resistance. •The functions of two sug genes overlap and compensate each other in QACs resistance. •SugR is the transcriptional suppressor of sugE1 and sugE2. •SugR regulates the sug locus by binding to the operon promoter. [ABSTRACT FROM AUTHOR]

Nanoemulsions can be applied as delivery systems that improve solubilization capacity for poorly soluble drugs, and enhance the drug loading. In this work, a molecular self-assembly of a nanoemulsion composed of benzalkonium chloride as surfactant, cyclohexane as oil phase, and ethanol as co-surfactant in water, was investigated by three 1 μs coarse-grained molecular dynamics simulations. Simulation results showed that the oil molecules placed in the hydrophobic core of the nanoemulsion and made its size larger, while the polar terminal groups of benzalkonium chloride chains dominated the surface. The ethanol co-surfactant molecules distributed throughout the system so that they did not concentrate in the hydrophilic shell of the nanoemulsion. After formation of the droplet, it remained stable until the end of the simulation. The nanoemulsion structure was compact and exhibited a prolate ellipsoid shape. The average value of radius of gyration of the nanoemulsion was 1.68 nm and physical radius, determined from the radius of gyration was 2.17 nm. [ABSTRACT FROM AUTHOR]

Purpose: We aimed to investigate the toxicity of 6 fixed-combination drugs for glaucoma therapy using human corneal epithelial sheets (HCES). Study design: Experimental. Materials and methods: We used 6 kinds of commercially available fixed-combination drugs: latanoprost/carteolol (LAT/CAR), latanoprost/timolol (LAT/TIM), tafluprost/timolol (TAF/TIM), travoprost/timolol (TRA/TIM), brinzolamide/timolol (BRZ/TIM), and dorzolamide/timolol (DRZ/TIM) including different preservatives. The cell viability and barrier function of the HCES after exposure to the eye drops for 10 or 30 minutes were assessed using the WST-1 assay and transepithelial electrical resistance (TEER) measurements, respectively. The HCES were also evaluated using hematoxylin and eosin (HE) staining and transmission electron microscopy. Results: The cell viability significantly decreased in the HCES treated with LAT/TIM or DRZ/TIM after 10 and 30 minutes and in those treated with BRZ/TIM after 30 minutes. The barrier function increased significantly in the HCES treated with LAT/CAR. Histologically, the HCES were damaged after treatment with LAT/TIM, BRZ/TIM, or DRZ/TIM for 30 minutes. Transmission electron microscopy indicated narrow intercellular spaces and multiple intercellular junctions in the HCES treated with LAT/CAR, TAF/TIM, or TRA/TIM. The HCES treated with DRZ/TIM, BRZ/TIM, or LAT/TIM contained cytoplasmic vacuoles and collapsed cellular structures. Conclusion: Glaucoma fixed-combination eye drops demonstrated a different toxic effect on the cell viability, barrier function, and morphologic changes of HCES. [ABSTRACT FROM AUTHOR]

The goal of this work was to synthesize hybrid thin films prepared combining polyamide-6 (N6) and microcellulose (CE) at various weight ratios. Products exhibited improved mechanical properties, temperature-tunable hydrophilicity, and antimicrobial features. The obtained N6@CE films were grafted with N-vinylcaprolactam (NVCL) using gamma-rays, providing temperature responsiveness in a range of 37–38 °C. The grafting degree was studied as a function of CE percentage on the film, monomer concentration, and absorbed dose. The grafting degree increased with the percentage of CE on the film, and the maximum grafting was achieved at monomer concentration and the irradiation dose of 20% NVCL and 20 kGy, respectively. NVCL grafting was confirmed by SEM, 13C-CPMAS NMR, FTIR-ATR, and XPS. SEM images attested formation of nanopores on the structure, caused by the grafting process, that consequently triggering on the new characteristics of the final materials. Potential performance of the composites as wound dressings was investigated in terms of their capability to loading and release of antimicrobial agents, such as vancomycin and benzalkonium chloride. NVCL grafting enhanced the uptake of both drugs, especially benzalkonium chloride, and regulated their release demonstrating antimicrobial effectiveness against Staphylococcus aureus. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the effects of topical autologous serum application on the ocular surface in patients with toxic corneal epitheliopathy induced by anti-glaucoma drugs. Methods: The patients who had corneal epitheliopathy because of preservative-containing anti-glaucoma eye drops were prospectively enrolled. The epitheliopathy was refractory to preservative-free artificial tear treatment. The patients topically applied 20% autologous serum to the eye eight times per day for 1 month. Baseline and one-month change in symptoms and signs were assessed by the Ocular Surface Disease Index (OSDI) questionnaire, tear film break-up time (TFBUT), Schirmer I values, corneoconjunctival staining scores, corneal sensitivity, InflammaDry® tear immunoassay, and tear cytokine profiles using a bead-based multiplex assay. Results: A total of ten consecutive patients were enrolled between January and August 2018 and evaluated after one-month treatment with 20% autologous serum eye drops. Significant improvement was observed in symptoms (OSDI scores from 25.5 ± 20.9 to 10.5 ± 12.0; P =.039), TFBUT (from 3.1 ± 1.8 s to 5.4 ± 2.3 s; P =.025), corneoconjunctival staining scores (from 7.7 ± 1.8 to 1.8 ± 1.9 NEI scale; P =.005), corneal sensitivity (from 4.6 ±.9 cm to 5.8 ±.5 cm; P =.013), and metalloproteinase-9 levels (P =.013). There were no significant changes in Schirmer I values and tear cytokine levels on multiplex assays. Treatment-related side effects were not detected. Conclusions: Topical instillation of 20% autologous serum is an effective treatment for toxic corneal epitheliopathy associated with anti-glaucoma eye drops. Trial registration number: KCT0003827. [ABSTRACT FROM AUTHOR]