Cetylpyridinium Research Articles

Alizarin Red S, Oxalic Acid and Cetylpyridinium Chloride-based Modified Photogalvanic Cell with Sustainable Conversion and Storage of Solar Energy

In this study, an integrated photogalvanic system of Alizarin red S, oxalic acid and cetylpyridinium chloride has been fabricated and used for the conversion of solar energy in to electrical energy with improved conversion efficiency and storage capacity. The photogalvanic cell is an H-shaped glass tube cell containing two electrodes dipped in a multifaceted electrolyte solution of dye-reductant-surfactant-alkali. By virtue of its photogalvanic action, it is capable of being charged by sun light. This system by way of variable concentration of chemical components were used to formulate a modified photogalvanic cell. The modified cell indicated significantly improved performance in terms of dark potential (778 mV), open-circuit potential (1189 mV), short-circuit current (420 µA), power (147.42 µW), charging time (17 min), half change time (16 min), conversion efficiency (2.16%) and fill factor (0.299).

Triclosan and its alternatives, especially chlorhexidine, modulate macrophage immune response with distinct modes of action

Since European regulators restricted the use of bacteriocidic triclosan (TCS), alternatives for TCS are emerging. Recently, TCS has been shown to reprogram immune metabolism, trigger the NLRP3 inflammasome, and subsequently the release of IL-1β in human macrophages, but data on substitutes is scarce. Hence, we aimed to examine the effects of TCS compared to its alternatives at the molecular level in human macrophages.LPS-stimulated THP-1 macrophages were exposed to TCS or its substitutes, including benzalkonium chloride, benzethonium chloride, chloroxylenol, chlorhexidine (CHX) and cetylpyridinium chloride, with the inhibitory concentration (IC10-value) of cell viability to decipher their mode of action. TCS induced the release of the pro-inflammatory cytokine TNF and high level of IL-1β, suggesting the activation of the NLRP3-inflammasome, which was confirmed by non-apparent IL-1β under the NLRP3-inhibitor MCC950 treatment d. While IL-6 release was reduced in all treatments, the alternative CHX completely abolished the release of all investigated cytokines.To unravel the underlying molecular mechanisms, we used untargeted LC-MS/MS-based proteomics. TCS and CHX showed the strongest cellular response at the protein and signalling pathway level, whereby pathways related to metabolism, translation, cellular stress and migration were mainly affected but to different proposed modes of action. TCS inhibited mitochondrial electron transfer and affected phagocytosis. In contrast, in CHX-treated cells, the translation was arrested due to stress conditions, resulting in the formation of stress granules. Mitochondrial (e.g. ATP5F1D, ATP5PB, UQCRQ) and ribosomal (e.g. RPL10, RPL35, RPS23) proteins were revealed as putative key drivers. Furthermore, we have demonstrated the formation of podosomes by CHX, potentially involved in ECM degradation.Our results exhibit modulation of the immune response in macrophages by TCS and its substitutes and illuminated underlying molecular effects. These results illustrate critical processes involved in the modulation of macrophages' immune response by TCS and its alternatives, providing information essential for hazard assessment.

A novel montmorillonite clay-cetylpyridinium chloride material for reducing PFAS leachability and bioavailability from soils

Soils contaminated by per- and polyfluoroalkyl substances (PFAS) present a significant threat to both ecological and human health. Extensive research efforts are currently underway to develop effective strategies for immobilizing these chemicals in soils. In this study, calcium montmorillonite was modified with cetylpyridinium chloride (CPC-CM) to enhance its electrostatic and hydrophobic interactions with PFAS. CPC-CM exhibited high adsorption for perfluorooctanoate acid (PFOA), perfluorooctane sulfonate (PFOS) and 8:2 fluorotelomer sulfonic acids (8:2 FTSA) across initial concentrations of 50–1000 μg/L, outperforming both the parent CM and L-carnitine modified CM. Soil leaching tests demonstrated the superior immobilization capabilities of the CPC-CM, maintaining an average PFAS leaching rate below 7% after 120-day incubation. In the context of human exposure scenarios, the in vitro bioaccessibility and in vivo bioavailability of PFAS in soils were measured by gastrointestinal extraction and mouse assay. CPC-CM treatment effectively reduced the bioaccessibility (by up to 84%) and bioavailability (by up to 76%) of PFAS in soils. Furthermore, the safety and efficacy of CPC-CM were evaluated using enteric microorganisms of mice. CPC-CM treatment mitigated PFAS-induced changes in the abundance of Bacteroidetes and Firmicutes, thereby reducing PFAS-induced health risks for humans. Overall, CPC-CM synthesized in this study demonstrated superior adsorption performance and application safety, offering a highly promising approach for remediating PFAS-contaminated soil.

Effect of preoperative chlorhexidine, essential oil, and cetylpyridinium chloride mouthwashes on bacterial contamination during dental implant surgery: A randomized controlled clinical trial

BackgroundAlthough the role of chlorhexidine and other mouthwashes in periodontal therapy has been elucidated, little information is available on their use as routine preoperative mouth rinses before surgery, especially in periodontal procedures such as dental implant surgery. ObjectiveThis study aimed to compare the efficacy of preoperative chlorhexidine, essential oil, and cetylpyridinium chloride mouthwashes in reducing bacterial contamination at the time of implant placement. Materials and MethodsEligible patients who underwent dental implant surgery were randomly divided into four groups based on the mouthwash used: (1) 0.12 % chlorhexidine, (2) essential oil, (3) cetylpyridinium chloride, and (4) saline (served as the control group). All the patients of each group rinsed preoperatively with 15 mL of the respective mouthwash for 60 s. Saliva samples before (pre) and immediately after rinsing with the mouthwash (post) and after suturing the flap (end) were collected on the day of the implant placement. Real-time quantitative polymerase chain reaction (qPCR) was performed to analyze the samples and quantify the targeted periodontal pathogens using a propidium monoazide (PMA) dye. ResultsForty patients were included in the study. Real-time qPCR demonstrated a significant reduction in the number of pathogens in the saliva samples of the mouthwash groups compared to that of the control group. A statistically significant difference was observed between the groups for the pre–post and pre–end samples (p < 0.001) but not for the post–end samples (p = 0.203). A statistically significant difference was observed between the chlorhexidine, essential oil, and cetylpyridinium chloride mouthwash groups and the saline group (P < 0.001). The bacterial counts significantly differed with and without the use of the PMA dye. ConclusionsPreoperative chlorhexidine, essential oil, and cetylpyridinium chloride mouthwashes can reduce the bacterial load at the time of implant placement, thereby reducing the incidence of implant-related complications.

Mitigating the attachment of Salmonella Infantis on isolated poultry skin with cetylpyridinium chloride.

To provide the poultry industry with effective mitigation strategies, the effects of cetylpyridinium chloride (CPC) on the reduction of Salmonella Infantis, hilA expression, and chicken skin microbiota were evaluated. Chicken breast skins (4×4 cm; N = 100, n = 10, k = 5) were inoculated with Salmonella (Typhimurium or Infantis) at 4°C (30min) to obtain 108 CFU/g attachment. Skins were shaken (30s), with remaining bacteria being considered firmly attached. Treatments were applied as 30s dips in 50 mL: no inocula-no-treatment control (NINTC), no treatment control (NTC), tap water (TW), TW+600 ppm PAA (PAA), or TW+0.5% CPC (CPC). Excess fluid was shaken off (30s). Samples were homogenized in nBPW (1 min). Samples were discarded. Salmonella was enumerated and Log10 transformed. Reverse transcriptase-qPCR (rt-qPCR) was performed targeting hilA gene and normalized using the 2-ΔΔCt method. Data were analyzed using one-way ANOVA in RStudio with means separated by Tukey's HSD (P≤0.05). Genomic DNA of rinsates was extracted, 16S rRNA gene (V4) was sequenced (MiSeq), and data analyzed in QIIME2 (P≤0.05 and Q≤0.05). CPC and PAA affected Salmonella levels differently with CPC being effective against S. Infantis compared to TW (P<0.05). Treatment with CPC on S. Infantis-infected skin altered the hilA expression compared to TW (P<0.05). When inoculated with S. Typhimurium, there was no difference between the microbiota diversity of skins treated with PAA and CPC; however, when inoculated with S. Infantis, there was a difference in the Shannon's Entropy and Jaccard Dissimilarity between the two treatments (P<0.05). Using ANCOM at the genus level, Brochothrix was significant (W = 118) among skin inoculated with S. Typhimurium. Among S. Infantis inoculated, Yersiniaceae, Enterobacterales, Lachnospiraceae CHKCI001, Clostridia vadinBB60 group, Leuconostoc, Campylobacter, and bacteria were significant (40<W>8). CPC and PAA-treated skins had lowest relative abundance of the genera. In conclusion, CPC mitigated Salmonella Infantis, altered hilA expression, and influenced the chicken skin microbiota.

Сравнение двух типов подвижных фаз для определения витаминов группы В методом тонкослойной хроматографии

Thin-layer chromatography (TLC) has been used to study the influence of a number of factors (the nature of the stationary phase, the nature and concentration of the organic solvents and surfactants, the pH of the buffer solution) on the chromatographic characteristics of B vitamins: B 1 (thiamine), B6 (pyridoxine), B12 (cyanocobalamin). The stationary phases were plates with polar (Sorbfil on a polymer (highperformance plates, HTLC) and aluminum substrates), weakly polar (Polyamide-6), and nonpolar (RP-18 on an aluminum substrate) sorbents. As micellar mobile phases – micellar solutions of cetylpyridinium chloride in the concentration range 5–10-4 – 5–10-1 M, sodium dodecyl sulfate in the concentration range 2,5–10-4 – 5–10-1 М. It has been established that among aqueous-organic mobile phases (MF) the best results have been obtained for MF of the composition acetonitrile – water (15:385) on polar high-performance plates. More effective than acetonitrile – water is the PF of the composition acetonitrile – cetylpyridinium chloride (15:85) in the presence of a phosphate buffer solution with pH = 3. For the last PF, TLC determination of vitamins B1, B6, B12 in pharmaceutical preparations with a Sr value of interval 0.01–0.06 has been developed.

Exploring the inhibitory activity and mechanism of cetylpyridine chloride: Unveiling a promising class of tyrosinase inhibitors

Cetylpyridine chloride (CPC), a quaternary ammonium compound renowned for its antimicrobial properties, has emerged as a promising tyrosinase inhibitor. However, the precise mechanism of its inhibitory effects remains elusive. Therefore, this study endeavors to elucidate CPC's inhibitory effects and molecular mechanisms through spectroscopic analyses and computational molecular docking. Our findings unveil CPC as a reversible, competitive inhibitor of tyrosinase, achieved through hydrophobic interactions that effectively obstruct the enzymatic active site. These insights prompted the evaluation of 25 CPC analogs, assessing their monophenolase and diphenolase activities. Notably, this investigation unveiled a previously unreported class of tyrosinase inhibitors, making a substantial contribution to the existing literature. Furthermore, a preliminary structure-activity relationship analysis was conducted on a series of CPC analogs, indicating the necessity of a long alkyl chain with a minimum length of 14 carbons and a hydrophilic functional group. Our results demonstrate the potential for designing novel tyrosinase inhibitors with enhanced inhibitory capabilities, while also shedding light on surfactant-protein binding mechanisms.

Effect of Commercial Children's Mouthrinses and Toothpastes on the Viability of Neonatal Human Melanocytes: An In Vitro Study.

In this study, we examined the cytotoxic effects of six commercial children's mouthrinses (designated as #1, #2, #3, #4, #5, and #6) and four commercial children's toothpastes (designated as #1, #2, #3, and #4) on primary human neonatal melanocytes that were used as a representative model for oral melanocytes. Mouthrinses diluted directly with culture medium (1:2, 1:5, 1:10, 1:100, and 1:1000) were added to monolayers of melanocytes for 2 min, followed by 24 h recovery, after which MTS cytotoxicity assay was conducted. The extracts of each toothpaste were prepared (50% w/v), diluted in culture medium (1:2, 1:5, 1:10, 1:50, 1:100, and 1:1000), and added to cell monolayers for 2 min (standard brushing time), followed by an analysis of cell viability after 24 h. Results showed that all mouthrinses except mouthrinse #4 showed significantly greater loss of cell viability, ascribed to cetylpyridinium chloride (CPC) that induced significant cytotoxicity to melanocytes (IC50 = 54.33 µM). In the case of toothpastes, the examination of cellular morphology showed that a 2 min exposure to all toothpaste extracts induced a concentration-dependent decline in cell viability, pronounced in toothpaste containing sodium lauryl sulfate (SLS) detergent. Further results suggested SLS to be the critical driver of cytotoxicity (IC50 = 317.73 µM). It is noteworthy that toothpaste #1 exhibited much lower levels of cytotoxicity compared to the other three toothpastes containing SLS. Taken together, these findings suggest that the melanocytotoxicity of children's mouthrinse (#4) and toothpaste (#1) is comparatively low. To the best of our knowledge, this is the first study to examine the impact of children's toothpastes and mouthrinses on neonatal primary human melanocytes. Future studies to investigate these findings in a realistic scenario replicating oral cavity conditions of the presence of microbiota, pellicle layer and saliva, and other cell types are warranted.

Unveiling the molecular interactions and antimicrobial activity of cetyl pyridinium bromide in ternary systems with short tetraalkylammonium bromide salts

Physicochemical properties of a surfactant cetyl pyridinium bromide (CPB) (0.2–2 mmol kg−1) has been investigated by the addition of greener additives, that is, aqueous tetraalkylammonium bromide (TAAB) salts at different concentrations (0.005, 0.010 and 0.015 mol kg−1) by employing techniques viz: conductivity, fluorescence and UV–visible spectra. In contrast to spectroscopic analysis, which was conducted at room temperature (298.15 K), conductivity measurements were made at various temperatures (298.15, 303.15, 308, and 313.15 K). The obtained electrical conductivity data has been used to compute the critical micelle concentration (cmc), which was also obtained from the UV–Visible and fluorescence methods. It is important to mention that the cmc values obtained from these methods are found to be in good agreement. Various thermodynamic parameters (ΔGmo, ΔHmo, and ΔSmo) have been calculated using conductivity data, the interpretation of which reveals that the interactions between CPB and TAAB are found to be both electrostatic and hydrophobic, however, hydrophobic interactions are found to be dominant in the ternary system. Additionally, the impact of TAAB on the antimicrobial activities of CPB has been evaluated by measuring the zone of inhibition, which explains why the CPB-TAAB system is more effective against gram-positive bacteria (Bacillus cereus and Staphylococcus aureus) than gram-negative bacteria (Escherichia coli and Salmonella typhi).Communicated by Ramaswamy H. Sarma

Spectroscopic insights for the enhanced partitioning and removal of Reactive Violet 5 by mixed micellar formulations under optimized conditions: An ionic-nonionic mechanistic approach

This study demonstrates MEUF (micellar enhanced ultrafiltration) as an effective method for the removal of Reactive Violet 5 (RV5) coming from the synthetic waste. MEUF technique is currently employed to decrease aqueous systems toxicity by employing cationic surfactants micellar media, specifically CPC (cetylpyridinium chloride) and CTAB (Cetyltrimethylammonium bromide). The study also examines the impact of nonionic surfactant on the addition of Triton X-100 (TX-100), on solubilizing capacity of the cationic surfactants. Our goal is to determine the optimal conditions for achieving maximum removal efficiency. RV5 partitioning constant, Kb as well as Gibbs energy of the partition ΔGp determines surfactant and dye molecules interaction. Dye molecules initially interact with ionic surfactants to form ion pairs. Subsequently, these ion pairs become incorporated into micelles and later on can subsequently be removed by MEUFThe maximum values of ΔGp (free energy of partition) were determined to be −42.30 kJmol−1 and −37.15 kJmol−1 using cationic surfactants, CPC and CTAB, respectively. Increase in pollutant size results in easy filtration. This study examines the impact of different factors, such as pH, transmembrane pressure, electrolyte (NaCl), surfactant concentration and revolutions per minute (RPM), on the removal of RV5 from an aqueous system. MEUF efficiency has been evaluated through the determination of permeate flux and rejection percentage values. It has been noticed that both surfactants had the potential to effectively encapsulate RV5. However, overall, the highest R% (rejection percentage) of 97.17% was attained.

Protocol for a Randomized, Open-Label Clinical Trial on the Effect of Mouthwash on Salivary SARS-CoV-2 Load.

Mouthwashes containing cetylpyridinium chloride (CPC) or on-demand aqueous chlorine dioxide (ACD) have potential to reduce the salivary severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) load in individuals with SARS-CoV-2 infection. This study will evaluate the effect of CPC and on-demand ACD mouthwashes on salivary SARS-CoV-2 levels in individuals with acute asymptomatic or mild SARS-CoV-2 infection (COVID-19) staying in a residential recuperation facility in Osaka, Japan. This randomized, open-label clinical trial will include three equal-sized groups (CPC mouthwash, on-demand ACD mouthwash, and placebo), with 30 participants per group. A stratified replacement block method will be used to ensure balanced allocation based on symptom presence and days since symptom onset. Participants will use mouthwash at set times for 7 days or until the end of recuperation. Saliva samples will be collected at multiple time points and tested for SARS-CoV-2 using quantitative reverse transcription polymerase chain reaction. The primary outcome will be changes in salivary SARS-CoV-2 viral load 2 h after the first mouthwash use compared with the pre-mouthwash level. Secondary outcomes will include changes in salivary viral load and clinical parameters at different time points. This study was registered with the Japan Registry of Clinical Trials on 18 October 2022 (jRCTs051220107).

Nigella sativa 3% Inhibition Test of Nаturаl Toothpаste Compаred Cetylpyridinum chloride (CPC) Toothpаste 0.01-0.1% on Аggregаtibаcter actinomycetemcomitаns

Periodontitis generаlly begins with gingivitis progresses to alveolar bone increаsing the risk of systemic diseаse. The primаry etiologicаl fаctor in the etiology of periodontаl diseаse is Аggregаtibаcter аctinomycetemcomitаns bacteria. Cetylpyridinium chloride (CPC) has a bactericidal effect by disrupting the function of bacterial membranes in the cytoplasm. CPC can also absorb negative charges from bacteria, increase bacterial cell wall permeability, decrease cell metabolism, and reduce bacterial attachment to teeth. Use of аntimicrobiаl toothpаste, such as Cetylpyridinium chloride (CPC), is one strategy to prevent periodontаl disease, but CPC is hаzаrdous in some quаntities. Аs а result, it should be compared to a natural toothpaste, specifically Nigellа sаtivа toothpаste. The objective of this study is to compare the аntibаcteriаl аctivity of nаturаl toothpаste contаining Nigellа sаtivа 3% with toothpаste contаining CPC 0.01% - 0.1% on Аggregаtibаcter аctinomycetemcomitаns. Experimentаl studies are used in this kind of research. The colony count method wаs used to аssess the nаturаl toothpаstes Nigellа sаtivа 3% аnd toothpаste contаining CPC 0.01- 0.1% for their cаpаcity in inhibiting the Аggregаtibаcter аctinomycetemcomitаns. Natural toothpаste containing Nigellа sаtivа 3% wаs completely inhibiting Аggregаtibаcter аctinomycetemcomitаns, compared to 0.01-0.1% CPC toothpаste. The significаnce level for the stаtisticаl test results wаs 0.000 (p&lt;0.05). The conclution of this research are the nаturаl toothpаste contаining Nigellа sаtivа 3% аnd toothpаste contаining CPC 0.06%–0.1% can effectively suppress the growth of the microorgаnisms Аggregаtibаcter аctinomycetemcomitаns.

Rheologically improved microemulsion for deactivation of simulants of blister and nerve agents

The efficiency of decontamination of blister and nerve agents was studied using the example of nucleophilic decomposition of paraoxone (O,O-diethyl-O-4-nitrophenyl phosphate) and oxidation of methylphenyl sulfide. Hydrogen peroxide solutions in an oil-in-water microemulsion containing synthetic nanoclay Laponite EP and polyvinylpyrrolidone polymer were studied as reactive decontamination systems. The base of the microemulsion consisted of an aqueous phase, a codetergent (isopropanol), oil (hexane), with a variation of detergent (cetylpyridinium chloride, sodium dodecyl sulfate, and Triton X-100). It was shown that the solubility of paraoxone and methylphenyl sulfide in the studied microemulsions increases by an average of 100 times or more compared to the solubility in water, and the substrate binding constants are 2–3 times higher than the binding constants in similar microemulsion media. It was found that the presence of nanoclay in the microemulsion provides a catalytic effect, i.e. an increase in the rate of decomposition of paraoxone and methylphenyl sulfide by at least 2 times. In addition, nanoclay thickens the microemulsion and, together with the polymer, increases the viscosity of the reaction medium. The determined kinetic parameters of decontamination and solubility of substrates allow us to conclude that the use of the investigated microemulsion system provides an acceleration of nucleophilic substitution and oxidation reactions by 150–350 times compared to the reaction rate in water.

Emergent properties of magnetic ions and nanoparticles in micellar solutions of surfactants: Use in fine technologies

Objectives. To establish expected emergent (unexpected) properties of magnetic materials when obtained in aqueous micellar solutions of surfactants (aqueous quantum materials), and their use in fine technologies.Methods. Chemical synthesis of magnetic nanoparticles in aqueous micellar solutions of surfactants of various nature. Characterization of magnetic solutions and nanoparticles by magnetic measurements, spectroscopy, diffractometry, small-angle X-ray diffraction, scanning probe microscopy, and others.Results. The term “water quantum material” refers to materials (micellar solutions) whose properties are mainly determined by the nuclear quantum effect on macroscopic scales (emergent property). Micellar solutions exhibit phenomena and functionality not always consistent with the classical theory of micellization. The article presents in detail the experimental results that suggest the manifestation of the emergent properties of magnetic materials obtained in aqueous micellar solutions of surfactants. In particular, Gd3+ ions in an aqueous micellar solution of sodium dodecyl sulfate exhibit paramagnetic properties, possibly indicating their random arrangement in solution contrary to the classical theory of micellization with an ordered adsorption layer on micelles. Hybrid Pt–Gd nanoparticles are formed in a quantum material with cetylpyridinium chloride as a matrix, although Gd3+ ions must be repelled by CP+ ions on micelles. Nanosized powders of cobalt ferrite and nickel ferrite obtained in a micellar solution of sodium dodecyl sulfate have superparamagnetic properties, although the presence of their precursor ions in the adsorption layer in classical micelles should lead to ferromagnetic properties.Conclusions. The synthesis of nanoparticles in a quantum material opens up the possibility of reducing ions of different signs in one stage during the processing of metallurgy waste, in order to obtain nanoparticles of various metals and their composites. Magnetic nanoparticles obtained in a quantum surfactant material self-assemble on various substrates, enabling the creation of materials whose residual magnetization and coercive field can be controlled at room temperatures.

Formation of vesicles between negatively charged carbon quantum dots and cationic surfactant cetylpyridinium chloride (CPC) due to oxidative photo induced electron transfer

The tuning of photo physical properties of highly emissive carbon quantum dots which was synthesized from citric acid in DMF medium through solvothermal method is investigated inside micelles formed by different types of surfactants like cationic surfactant cetylpyridinium chloride (CPC), cetrimonium bromide (CTAB), anionic surfactant sodium dodecyl sulfate (SDS) and neutral surfactant polyethylene glycol tert-octyl phenyl ether (TX100), polyoxoethylene lauryl ether (BRIJ-35). Interestingly, only CPC interacts with greater extent and formed co-assembly with negatively-charged carbon quantum dots (CQDs) whereas other surfactants like CTAB, SDS, TX100 and BRIJ-35 do not alter the fluorescence intensity extensively. This results in the formation of a non fluorescent vesicle. No phase separation was observed over the large concentration barrier of the CPC surfactant. However, no such vesicle formation takes place for another cationic surfactant CTAB excluding the role of only electrostatic interaction. The synthesized vesicle is characterized by various techniques including HRTEM, DLS. For the aqueous solution of CQDs having concentration of 0.5 mg/ml, addition of CPC leads to formation of different sized vesicles of size 40 nm to 100 nm. The driving force behind this formation of non-fluorescent vesicles is oxidative photo induced electron transfer which is revealed by the highest occupied molecular orbital (HOMO) –lowest unoccupied molecular orbital (LUMO) interaction between the donor (CQDs) and the acceptor (CPC). We trust such type vesicle can be a suitable alternative for drug carriers, biomarkers and other various applications also.

Hybrid mesoporous silica materials templated with surfactant polyion complex (SPIC) micelles for pH-triggered drug release

New Surfactant PolyIon Complex (SPIC) micelles were assembled by electrostatic complexation of an antibacterial cationic surfactant, cetylpyridinium chloride (CPC), and a double hydrophilic block copolymer (DHBC) containing a neutral comb block of poly(oligo(ethylene glycol)) methyl ether acrylate (PEOGA) and a weak polyacid block of poly(acrylic acid) (PAA). The corresponding SPIC micelles, with a CPC/PAA core and a PEOGA corona, were successfully used as structure directing and functionalizing agents in a soft and sustainable sol-gel strategy, yielding hybrid mesoporous silica (MS) materials with a monomodal pore size distribution centred at 2.8 nm. The influence of synthesis parameters, including the pH, concentrations and ratios of components, was systematically investigated. The obtained hybrid MS materials were intrinsically functional, with PEOGA blocks anchored in silica walls via H-bonding, while weak polyacid blocks, complexed with CPC, were confined within the mesopores. The response of the materials to pH changes (pH 7.4, 4.2 and 3) indicated remarkable stability of the anchored DHBC, while CPC was selectively released under the acidic conditions typical of orodental biofilm microenvironments. This result is noteworthy, since the release of encapsulated amphiphilic drugs into water is less favorable than that of hydrophilic drugs. Owing to the control of their pore and functionality properties, ordered hybrid silica materials templated and functionalized with SPIC systems will be materials of choice for developing pH-responsive biomedical devices using wet processing techniques.

Disinfectant resistance of Salmonella enterica isolated from retail chicken in Hanoi, Vietnam

Salmonella enterica is the most common foodborne pathogen found in poultry processing and slaughterhouses; therefore, understanding the resistance of this bacteria group is critical for effective pathogen control. This research in Vietnam provides a new field for studying resistance to biocides and disinfectants, along with the distribution of genes coding for this characteristic in Salmonella species members. According to the Clinical and Laboratory Standards Institute (CLSI) guidelines, 119 strains of Salmonella bacteria underwent testing for minimum inhibitory concentration (MIC) with two compounds, BKC (benzalkonium chloride) and CPC (cetylpyridinium chloride). Moreover, these Salmonella strains were further characterised based on the genes responsible for disinfectant resistance. The results showed that the MICs of BKC and CPC were between 12.5-25 and 6.25-12.5 μg/ml, respectively. Furthermore, the presence of two genes, qacEand qacE∆, discovered in 61% (73/119) and 60% (72/119) of the strains, indicates the wide spread of disinfectant resistance genes is a novelty in the resistance of this bacteria group.

An exploratory study of drug concentration and inhibitory effect of cetylpyridinium chloride buccal tablets on SARS-CoV-2 infection among 10 Chinese subjects.

It was evidenced that cetylpyridinium-chloride (CPC) mouthwash could inhibit SARS-COV-2 activity and reduce salivary viral load, thus reducing SARS-CoV-2 transmission. However, due to insufficient residence time in the oral cavity, CPC-containing mouthwashes have no prolonged antiviral effect. The duration of action of the CPC buccal tablet is expected to be longer than that of the mouthwash. However, there are currently no reports on the salivary drug concentration of CPC buccal tablets. The study aimed to investigate the salivary drug concentration of CPC buccal tablets and the antiviral effect of CPC on SARS-CoV-2 in vitro. This is a single-dose, single-arm clinical trial, involving 10 Chinese healthy subjects who received 2-mg CPC buccal tablet to collect saliva samples and to detect saliva concentration at different timepoints within 2h (Clinical Trial Registration Number: NCT05802628, Registration Date: April 6, 2023). CPC concentration in saliva was detected by liquid chromatography tandem mass spectrometry (LC-MS/MS), and pharmacokinetic parameters were calculated based on the non-compartmental model. With an in vitro antiviral experiment, the activity of CPC buccal tablets against SARS-CoV-2 and its cellular toxicity was tested. Drug concentrations in saliva at 15 min, 30 min, 1h, 1.5h, and 2h after administration were 8008.33 (1042.25, 41081.11), 2093.34 (373.15, 5759.83), 1016.58 (378.66, 3480.68), 891.77 (375.66, 6322.07), and 717.43 (197.87, 2152.71)ng/mL. PK parameters of saliva concentration: Cmax = 8008.33 (1042.25, 41081.11)ng/mL, AUC0-t = 4172.37 (904.42, 13912.61)ng/mL*h, AUC0-∞ = 6712.85 (1856.77, 19971.12)ng/mL*h, T1/2 = 1.22 (0.59, 2.83)h, Tmax = 0.25 (0.25, 0.25)h. As determined in in vitro experiment, CPC was active on SARS-CoV-2 with cytotoxic and inhibitory activity of CC50 = 35.75 μM (≈12155 ng/mL) and EC50 = 7.39 μM (≈2512.6ng/mL). The comparison between the salivary CPC concentration and EC50/CC50 values from in vitro antiviral experiments suggests that CPC buccal tablets may inhibit SARS-CoV-2 activity, and the inhibition may last for approximately 30 min without cytotoxicity.

Electrochemical Sensor Based on CuO Nanoparticles-Modified Graphite Electrode for the Detection of Malachite Green

In this study, the development of a graphite paste electrode (GPE) modified by copper oxide nanoparticles (CuO@GP) to be used as a practical and economical sensor for the electrochemical sensing of malachite green (MG) has been elucidated. The sol–gel technique was applied for the synthesis of CuO nanoparticles (NPS) from copper chloride (CuCl[Formula: see text], where the surfactant cetylpyridinium chloride (C[Formula: see text]H[Formula: see text]NCl) played the role of a capping agent. The synthesized CuO NPS were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). A bare GPE was modified using these CuO NPS and thus developed; the new electrode was used as a working electrode (WE) in a 3-electrode system for studying the cyclic voltammetry (CV) and differential pulse voltammetry (DPV) responses of MG. Phosphate buffered saline (PBS) with a pH value of 6 was used as the optimum buffer. Using DPV, a widely linear operational range of 1–1000 [Formula: see text]M was obtained with a detection limit of 0.18 [Formula: see text]M. This CuO@GP provided excellent repeatability, reproducibility and prolonged stability for the MG molecule. For the selectivity study, various common interfering agents were used to observe MG’s corresponding peak current variation. Moreover, this electrode demonstrated a successful application for detecting MG in pond water and fish flesh. This method is effective for similar other applications.

In Vitro Effect of Mouthrinses on the Microhardness of Three Different Nanohybrid Composite Resins.

Daily use of different mouthrinses at home or in the dental office can alter the properties of resin hardness. The present study aimed to compare Vickers microhardness (VHN) in vitro of nanohybrid composite resins (NCRs) immersed in mouthrinses. In total, 120 discs (10 ⨯ 2 mm) were prepared from three NCR shade A2 (n = 40/group) with FiltekTM Z350 XT (Z350XT), Tetric EvoCeram (TEC), and Polofil NHT (PNHT). The specimens were incubated in artificial saliva (37°C ⨯ 24 hr). Specimens were distributed into four mouthrinses (n = 10/group) of artificial saliva (control), chlorhexidine (CHX 0.12%, pH 5.6), cetylpyridine chloride (CPC 0.075%, pH 5.84), and CHX 0.12% + CPC 0.05% (pH 6.2) (2 times/day, 2' ⨯ 12 hr). The VHN (300 gf/10") was measured after 24 hr, 14, and 21 days. Data were analyzed by three-way analysis of variance, followed by post hoc Tukey analysis at 0.05 level of significance. The results revealed a global effect of the interaction of the mouthrinses ⨯ time between NRC evaluated (P=0.001). Baseline VHN in PNHT and Z350XT was higher than TEC. Within each group of NCR, VHN of CHX + CPC > other mouthrinses (PNHT/14 days; Z350XT/21 days), and >CPC (Z350XT/14 days). In mouthrinses-intragroups, VHN of PNHT and Z350XT decreased at 14 days (CHX, CPC) and was maintained over time in NCR (CHX + CPC). VHN-TEC was similar among groups. Microhardness showed differences due to the interaction of the type of NCR, the composition of the mouthrinses, and time. VHN decreased after 14 days and was more affected in composite resins with lower filler content and in mouthrinses with a lower pH.