Antimicrobial Formulations Research Articles

Exploring the Potential of Nitrofurantoin for Infection Control in Regenerative Endodontics: in vitro study.

This study assessed a new antimicrobial paste formulation containing nitrofurantoin for regenerative endodontics against multispecies biofilms. Four groups of 11 single-root teeth each were tested: Negative control group (BHI + microorganisms); Hoshino 1 conventional tri-antibiotic paste group (1:1:1 ratio); Hoshino 5 group (5:5:5 ratio); Experimental group with nitrofurantoin, ciprofloxacin, and metronidazole. Minimum inhibitory concentrations of each antimicrobial were determined. A polymicrobial biofilm (E. faecalis, S. aureus, P. aeruginosa, C. albicans) was created in root canals, and pastes were inserted for 3 minutes with lentulo. After 7 days, samples were sonicated and spectrophotometrically analyzed. Microbiological assays, plasma membrane permeabilization, confocal laser scanning microscopy (CLSM), and scanning electron microscopy (SEM) evaluated biofilm eradication. Statistical significance was set at p < 0.05. Spectrophotometry indicated Experimental group outperformed Hoshino 1 group and Negative control group (p<0.05), with results similar to Hoshino 5 group (p>0.05). Experimental group showed increased membrane damage compared to Hoshino 1 group and Hoshino 5 group. CLSM and SEM revealed fewer microorganisms and no residual biofilm in Experimental group. Substituting minocycline with nitrofurantoin in the paste effectively reduced microorganism counts in root canals system.

Determination of antimicrobial activities and DNA protection properties of Scytosiphon lomentaria extracts

Scytosiphon lomentaria is a brown algae that has many promising biological activities in medicine as well as being consumed as food in many countries. This study aims to investigate the antimicrobial, antimutagenic and DNA damage protective activity of S. lomentaria by obtaining hexane, methanol and water extracts. To evaluate the antimicrobial effect of the extracts, minimum inhibitory concentration (MIC) tests were performed on both yeasts and bacteria. The antimutagenic activities of the extracts were investigated by the Ames test, and their protective effects against oxidative DNA damage were investigated by agarose gel electrophoresis using pBR322 plasmid DNA. Antimicrobial results showed that hexane methanol and aqueous extract were more effective on Candia albicans (5, 2.5 and 2.5 mg/mL, respectively) compared to all strains used. All concentrations of the methanol extract exhibited strong antimutagenicity (more than 40% inhibition) on both TA98 and TA100 mutant strains. It was determined that the extracts protected DNA against oxidative DNA damage. The results show that S. lomentaria extracts have antimicrobial activity and DNA protection properties, making them have the potential to be evaluated as new natural resources that can be used in antimicrobial and anticancer formulations

Testing low-risk bioactive compounds on Halyomorpha halys: an improved pipeline of analyses to investigate their effects on the bacterial endosymbiont Candidatus Pantoea carbekii.

The brown marmorated stink bug Halyomorpha halys has become an invasive insect pest of many crops. A promising control strategy to manage the proliferation of H. halys is based on the suppression of its obligate and vertically transmitted uncultivated symbiotic bacterium Candidatus Pantoea carbekii through surface-sterilization of H. halys eggs. Indeed, the application of antimicrobial formulations on the eggs of H. halys could cause mortality of endosymbiont and consequently of newly emerged nymphs. In this study, a microbial live/dead assay was applied directly on H. halys eggs to evaluate Ca. P. carbekii loss of viability after treatments with seven commercial formulations including fungicides (copper hydroxide, sulphur, sweet orange essential oil) and plant biostimulants (flavonoids and chestnut tannin extract) compared with two disinfectants for civil and industrial use (sodium hypochlorite/hydrated sodium/tetraborate decahydrate and peracetic acid/hydrogen peroxide). Impact of mode of application was also evaluated, as surface treatment of egg masses was performed through spraying and dipping in laboratory conditions. Antimicrobial activity data were finally complemented with observations of egg hatching and vitality of the nymphs. The optimization of live/dead staining is useful for evaluating Ca. P. carbekii mortality directly on eggs, providing a rapid and reliable culture-independent approach. Sodium hypochlorite, copper, sulphur, tannins and sweet orange essential oil showed an antimicrobial effect against Ca. P. carbekii and a H. halys egg hatching reduction and nymph's vitality. The antimicrobial and insecticidal effects of these commercial products should be further studied to assess their in-field efficiency as well as the impact of these substances on non-target organisms. The approach followed in this study could be considered a robust pipeline of analyses to evaluate the effectiveness of antimicrobial eco-friendly compounds in symbiotic control of H. halys. © 2024 Society of Chemical Industry.

Modelling of Cetylpyridinium Chloride Availability in Complex Mixtures for the Prediction of Anti-Microbial Activity Using Diffusion Ordered Spectroscopy, Saturation Transfer Difference and 1D NMR.

Background/Objectives: A range of NMR techniques, including diffusion ordered spectroscopy (DOSY) were used to characterise complex micelles formed by the anti-microbial cationic surfactant cetylpyridium chloride and to quantify the degree of interaction between cetylpyridium chloride and hydroxyethyl cellulose in a variety of commercially relevant formulations as a model for the disk retention assay. Methods: This NMR-derived binding information was then compared with the results of formulation analysis by traditional disk retention assay (DRA) and anti-microbial activity assays to assess the suitability of these NMR techniques for the rapid identification of formulation components that could augment or retard antimicrobial activity DRA. Results: NMR showed a strong ability to predict anti-microbial activity for a diverse range of formulations containing cetylpyridinium chloride (CPC). Conclusions: This demonstrates the value of this NMR-based approach as a rapid, relatively non-destructive method for screening commercial experimental anti-microbial formulations for efficacy and further helps to understand the interplay of excipients and active ingredients.

Antimicrobial Efficacy of GS-2 on Reusable Food Packaging Materials for Specialty Crops.

The European Union (EU) regulations mandate 10% of all food packaging to be reusable by 2030. United States (U.S.) exporters of specialty crops face new challenges in ensuring microbiological food safety using reusable packaging. A novel antimicrobial formulation consisting of ammonium carboxylate salt of capric acid and L-arginine (GS-2) was recently developed as a spray coating chemical for food packaging materials. In this study, we evaluated the antimicrobial efficacy of GS-2 against microbial strains representing three foodborne bacterial pathogens (Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enterica), one fungal spoilage organism (Aspergillus niger), and one surrogate viral pathogen (murine norovirus) on three reusable plastic materials (acrylonitrile butadiene styrene, high-density polyethylene, and polypropylene) and one cardboard packaging material, respectively. Different chemical concentrations, exposure times, and storage conditions were individually evaluated for the relative antimicrobial efficacies of GS-2 against these microorganisms. Our results showed that GS-2 was highly effective for inactivating bacterial pathogens on both plastic and cardboard surfaces. For instance, 3% GS-2 achieved a >5 log CFU/in2 reduction in E. coli O157:H7, L. monocytogenes, and S. enterica on tested plastic surfaces at an exposure time of 60 min. However, its efficacy against A. niger and murine norovirus was less optimal, resulting in a ≤1 log CFU/in2 reduction on all tested surfaces. Based on our study, GS-2 demonstrated a strong potential as an antibacterial coating reagent for reusable food packaging materials to minimize pathogen contamination and ensure the safety of the specialty crops.

GC-MS profiling of the leaf extract of Garcinia pedunculata, molecular docking, ADME/drug likeness predictions and toxicity analysis

Medicinal plants have long been valued for their efficacy, cultural acceptance and lower side effects. Amidst rising concerns about multidrug-resistant bacteria, there is an increasing push to identify novel plant-based drugs with unique mechanisms of action. Garcinia pedunculata, commonly used as food and traditional medicine among tribal communities in North Eastern India, was investigated for its potential medicinal properties. The study involved analyzing the phytoconstituents of the methanolic leaf extract using GC-MS (Gas Chromatography- Mass Spectrometry), which identified 30 compounds. These compounds were further evaluated through in silico studies, including drug-likeness assessments and molecular docking. Molecular docking results indicated that the compounds strongly interacted with Penicillin Binding Protein 4 (PBP4) of Staphylococcus aureus (S aureus), a well-known drug target. Notably, ethane-1,1-diol dipropanoate demonstrated favorable drug-like properties, meeting four out of five drug filters and exhibiting promising physiochemical characteristics, lipophilicity, solubility and pharmacokinetic profiles with minimal toxicity. This suggests its potential for development into novel antimicrobial formulations. Further research using animal models is underway to validate these findings in vivo.

Rational design of a Nano-Antibiotic chitosan hydrogel for the bacterial infection Therapy: In vitro & ex vivo Assessments

In modern times, many antibiotics have become less effective as microorganisms develop resistance. Besides antibiotic resistance, another bacterial strategy that contributes to the capacity to withstand antimicrobials is biofilm formation. Because of these bacterial survival strategies, the desired response cannot be achieved with conventional treatment. Considering the limited discovery of new compounds, the most logical approach is to reconstruct existing antimicrobial molecules with nano-drug delivery systems. With this scientific approach, the aim of the study is to develop a novel nano-antibiotic hydrogel formulation containing silver nanoparticles, chitosan, and amoxicillin. Endodontic disease was used as a model of biofilm-mediated infection, and the antibacterial activity of nano-antibiotic hydrogel was evaluated with the E. faecalis standard bacterial strain. By adopting the Box-Behnken design for the optimisation of formulation variables, an innovative pharmaceutical formulation with antimicrobial and antibiofilm activity was successfully obtained. Further characterisation studies, including nanoparticle characterisation, in vitro cytotoxicity, and ex vivo activity studies, were carried out on dental samples using the optimised formulation. All results were compared with antimicrobial agents routinely used in endodontic treatment. The findings mainly conclude that the optimised nano-antibiotic hydrogel may be an alternative antimicrobial formulation since it is non-cytotoxic and exhibits high antibiofilm activity.

Evaluation of the long-term protection conferred by an organosilicon-based disinfectant formulation against bacterial contamination of surfaces.

The aim of this work was to evaluate the efficacy of an organosilicon-based, commercially available antimicrobial formulation in the My-shield® product line against bacterial surface contamination. The antimicrobial product was tested in vitro for its long-term persistence on surfaces and effectiveness against Staphylococcus aureus biofilms in comparison to 70% ethanol and 0.1% or 0.6% sodium hypochlorite. Field testing was also conducted over 6 weeks at a university athletic facility. In vitro studies demonstrated the log reductions achieved by the test product, 70% ethanol, and 0.1% sodium hypochlorite were 3.6, 3.1, and 3.2, respectively. The test product persisted on surfaces after washing and scrubbing, and pre-treatment with this product prevented S. aureus surface colonization for up to 30 days. In comparison, pre-treatment with 70% ethanol or 0.6% sodium hypochlorite was not protective against S. aureus biofilm formation after seven days. The field test demonstrated that weekly applications of the test product were more effective at reducing surface bacterial load than daily applications of a control product. The test product conferred greater long-term protection against bacterial growth and biofilm formation by S. aureus than ethanol and sodium hypochlorite. Even with less frequent applications, the test product maintained a high level of antimicrobial activity.

Bioadhesive Polymeric Films Containing Rhamnolipids, An Innovative Antimicrobial Topical Formulation.

Acne affects most of the world's population, causing an impact on the self-esteem of adolescents and young adults. One of the causes is the presence of the bacteria Cutibacterium acnes which are part of the natural microbiota of the skin. Topical treatments consist of anti-inflammatory and antibiotics, which could select resistant strains. Alternatives to the antibiotic are biocomposites that have antimicrobial activity like biosurfactants which are produced by bacteria. An innovative way of applying these compounds is bioadhesive polymeric films that adhere to the skin and release the active principle topically. Rhamnolipids have great potential to be used in the treatment of acne because they present antimicrobial activity against C. acnes in low and safe concentrations (MIC of 15.62µg/mL, CBM of 31.25µg/mL and CC50 of 181.93µg/mL). Four films with different rhamnolipids concentrations (0.0; 0.1; 0.2; and 0.3%, w/w) were obtained as to visual appearance, mass variation, thickness, density, solubility, pH, water vapor transmission, mechanical properties (folding endurance, bioadhesion strength, tensile strength, elongation at break and Young's modulus), scanning electron microscopy and infrared. The results show that these formulations had a homogeneous appearance; elastic mechanical properties; pH similar to human skin and bioadhesive. The polymeric films containing rhamnolipids were effective against C. acnes, in the in vitro test, at the three concentrations tested, the film with the highest concentration (0.3%, w/w) being the most promising for presenting the highest antimicrobial activity. Thus, the polymeric film containing rhamnolipids has the potential to be used in the treatment of acne.

Formulation, Optimization, and Evaluation of Non-Propellent Foam-Based Formulation for Burn Wounds Treatment

Burn injuries worldwide pose significant health risks due to frequent microbial infections, which worsen complications and increase mortality rates. The conventional antimicrobial formulations are available in the form of ointments and creams. These formulations are very greasy and stick to the clothes. The applications of these formulations by finger or applicator produce pain in the affected area and incur the possibility of microbial infection. To overcome these hurdles, authors developed a novel non-propellent foam (NPF) based formulation containing chlorhexidine for effective topical delivery. Initially, NPF containing Labrasol® (26.7%), sodium lauryl sulfate (1.2%), hydroxy propyl methyl cellulose (0.56%), butylated hydroxytoluene (0.1%), ethanol (1%), and distilled water was prepared and assessed for its consistency, and ability to form foam. The NPF was statistically optimized using the Box-Behnken design to determine the effect of polymer and surfactants on the critical foam properties. The optimized formulation showed a collapse time of 45 s with a unique nature of collapsing upon slight touch which is highly beneficial for burn patients with microbial infection. The diffusion study showed that more than 90% of the drug was released within 6 h. The skin permeation study showed that 23% of the total drug permeated through the skin after 6 h with 7.64 µg/cm2/h permeation flux. The developed formulation showed good antibacterial activity. The minimum inhibitory concentration of prepared NPF was found to be 2.5 µg/mL, 2.5 µg/mL, and 5.0 µg/mL against E. coli (MTCC-1687), P. aeruginosa (MTCC-1688), and S aureus (MTCC-737) respectively. The developed NPF formulation showed quick collapse time, excellent spreadability, good anti-bacterial activity, and a non-sticky nature representing a promising avenue for burn wound treatment without using any applicator.

Surveillance of Antimicrobial Use in Long-Term Care Facilities: An Antimicrobial Mapping Survey

ObjectivesTo explore antimicrobial management processes in Australian residential aged care facilities (RACFs), including antimicrobial prescribing, supply, administration, and documentation to inform surveillance activities. DesignVoluntary, online cross-sectional survey. Setting and ParticipantsThe survey was disseminated to all South Australian RACFs (n = 237) seeking participation from an infection prevention and control lead (preferred respondent), a nurse or senior RACF staff member, or an aged care pharmacist. MethodsThe survey was open during May-June 2023. Questions aimed to understand clinical and medication management systems, sources of antimicrobial prescription and supply, management by external health care providers and documentation of antimicrobial administration. A process map of antimicrobial management in RACFs was developed. ResultsOf the 54 RACFs included in the analysis (29.5% response rate), most used an electronic clinical documentation system (74.1%) or a hybrid electronic paper-based system (22.2%). Medication charts were either electronic (81.0%), hybrid (5.6%), or paper-based (13.0%). Antimicrobials were prescribed by the resident's usual general practitioner, but also by locums, hospital or specialist physicians, nurse practitioners, virtual care physicians, and dentists. Oral, topical, and inhaled antimicrobial formulations were usually supplied by community pharmacies, and intravenous formulations were predominately supplied by hospitals for administration by outreach nurses. Almost all RACFs (96.2%) had imprest stock of antimicrobials that included both oral and intravenous formulations. Antimicrobials were predominately administered by an enrolled nurse or a registered nurse. Conclusions and ImplicationsAntimicrobial management in RACFs is complex, particularly during care transitions. Multiple prescribers and sources of antimicrobials, use of different systems for clinical documentation, particularly by external health care providers, and clinical governance relating to imprest supplies were identified as key areas where medication management could be improved. Addressing these gaps will facilitate comprehensive, real-time antimicrobial surveillance in Australian RACFs.

The Assessment of Physicochemical and Antimicrobial Properties of Hydrophilic Gels Containing Tetracycline Hydrochloride and Various Concentrations of Ethanol.

The high prevalence of acne, which affects nearly 85% of adolescents and young adults, underscores the importance of exploring new therapeutic solutions. The aim of the present study was to design a stable hydrogel formulation containing tetracycline hydrochloride (TC) in the presence of ethanol at various concentration levels. The antibiotic stability was assessed over a period of 84 days using the HPLC method. The rheological properties of the formulations and their microbiological activity were also evaluated. Hydrogels without ethanol and those containing 5% and 25% alcohol showed similar rheological properties and high stability of the antibiotic throughout the observation period. The formulation with the highest ethanol content of 50% differed significantly from the others in terms of rheological properties. Although the flow and viscosity curves were like those of the other formulations, the viscosity values were significantly lower. The stability of tetracycline in this formulation was also significantly lower, and by the 84th day of observation, the concentration of the drug had decreased to almost 45% of its initial content. The formulations containing the highest concentration of ethanol displayed the highest activity against the biofilm of the acne-causing agent, Cutibacterium acnes. The study demonstrated the possibility of developing stable and antimicrobial effective hydrogel formulations with tetracycline and ethanol as a substance enhancing drug penetration into the hair follicles.

Inhibitory activity of natural antimicrobial compounds against histamine-forming bacterial isolates from cheese

This study was conducted to investigate the presence of histamine-forming bacteria in cheeses, and to assess the impact of naturally-occurring antimicrobials on isolates' viability and histamine-forming potential. Cheese isolates' ability to produce histamine was evaluated by incubation in the presence of the histamine precursor; qualitative detection with a pH indicator and a quantitative analysis by high-performance liquid chromatography. Eight of the 114 isolates were able to produce histamine, but only one was capable of generating histamine at high concentrations. Histamine-producing isolates were identified by matrix-assisted laser desorption ionisation-time of flight mass spectrometry. Isolated strain C_MRSV_25A_4 was the microorganism with the highest capacity to produce histamine, and was identified as Lacticaseibacillus rhamnosus. The antimicrobial potential of natural antimicrobials was tested against this isolate. The results showed that carvacrol, cinnamaldehyde, eugenol, thymol and nisin exhibited remarkable bactericidal activity. These compounds’ inhibitory potential was evaluated against the histamine-generating ability of strain C_MRSV_25A_4 at three concentrations of interest: minimum bactericidal concentration (MBC), MBC/2 and MBC/4. The results on histamine-forming capability at sub-bactericidal concentrations were promising. Given these results, we propose novel antimicrobial formulations based on natural antimicrobials as efficient strategies to reduce potential microbial contamination and histamine accumulation throughout cheese production.

Antimicrobial and Anesthetic Niosomal Formulations Based on Amino Acid-Derived Surfactants.

This work proposes the development of new vesicular systems based on anesthetic compounds (lidocaine (LID) and capsaicin (CA)) and antimicrobial agents (amino acid-based surfactants from phenylalanine), with a focus on physicochemical characterization and the evaluation of antimicrobial and cytotoxic properties. Phenylalanine surfactants were characterized via high-performance liquid chromatography (HPLC) and nuclear magnetic resonance (NMR). Different niosomal systems based on capsaicin, lidocaine, cationic phenylalanine surfactants, and dipalmitoyl phosphatidylcholine (DPPC) were characterized in terms of size, polydispersion index (PI), zeta potential, and encapsulation efficiency using dynamic light scattering (DLS), transmitted light microscopy (TEM), and small-angle X-ray scattering (SAXS). Furthermore, the interaction of the pure compounds used to prepare the niosomal formulations with DPPC monolayers was determined using a Langmuir balance. The antibacterial activity of the vesicular systems and their biocompatibility were evaluated, and molecular docking studies were carried out to obtain information about the mechanism by which these compounds interact with bacteria. The stability and reduced size of the analyzed niosomal formulations demonstrate their potential in pharmaceutical applications. The nanosystems exhibit promising antimicrobial activity, marking a significant advancement in pharmaceutical delivery systems with dual therapeutic properties. The biocompatibility of some formulations underscores their viability. The proposed niosomal formulations could constitute an important advance in the pharmaceutical field, offering delivery systems for combined therapies thanks to the pharmacological properties of the individual components.

Photocatalytic degradation of organic dyes and biological potentials of biogenic zinc oxide nanoparticles synthesized using the polar extract of Cyperus scariosus R.Br. (Cyperaceae)

Abstract In this study, the polar root extract of Cyperus scariosus R.Br. was used for the biogenic synthesis of ZnO NPs. The results of this study show that ZnO NPs have a spherical structure with an average size of 85.4 nm. The synthesized catalysts were tested for their photocatalytic activity by degrading methyl orange and methylene blue under sunlight. Improved degradation efficiencies of 79.44% and 84.92% were achieved within 120 min. ZnO NPs exhibited strong antibacterial activity against both Gram-positive Listeria monocytogenes (18 mm) and Staphylococcus epidermidis (20 mm) and Gram-negative strains of Escherichia coli (16 mm) and Bordetella bronchiseptica (14 mm), as shown by the inhibition zones, which were comparable to the positive control (ceftriaxone) but larger than the plant root extract. ZnO NPs showed high antioxidant activity, as a ferric-reducing antioxidant power assay value of 66.29 µg (AAE µg·mL−1) and a DPPH value of 57.44 µg (AAE µg·mL−1) were obtained at a concentration of 500 µL, which was higher than those of the C. scariosus root extract. Quantification of the total phenolic and flavonoid content yielded values of 57.63 µg (GAE µg·mL−1) and 70.59 µg (QCE µg·mL−1), respectively. At a concentration of 500 μL (1 mg·mL−1), the tested nanoparticles (NPs) showed a greater anti-inflammatory effect (84.12%) compared to the root extract of C. scariosus (34.39%). Overall, our findings highlight the versatile properties of green synthesized ZnO NPs and demonstrate their potential for environmental remediation and antimicrobial formulations, as well as promising candidates for further investigation in biomedical fields such as drug delivery and therapy.

Eco-Dyeing and Functional Finishing of Cotton Fabric Using a Natural Colour Derived From Lotus Seed: Enhanced Fastness Properties with Chitosan

Medicinal plant-based dyeing introduces vibrant colours alongside antibacterial and anti-odor properties, fostering sustainability. Innovations include mass sampling for consistent pigment production. Furthermore, lotus seedpods, rich in bioactive compounds, exhibit potential in diverse fields. Chitosan, a biopolymer derived from chitin, boasts versatility in drug delivery systems, wound healing, and antimicrobial applications. This experimental inquiry delves into the dyeability and antimicrobial efficacy of cotton fabric subjected to treatment with chitosan and dyed using Lotus seeds. The investigation encompasses varied parameters such as dye concentration, duration, and temperature for fabric dyeing. The study elucidates the aqueous extraction methodology for dye from Lotus seeds, the chitosan-based mordanting techniques. Standardized assessments are utilized to gauge colour fastness characteristics, encompassing washing, rubbing, and perspiration fastness, along with assessing the antimicrobial attributes of the treated cotton fabric. The study indicates that the application of chitosan-treated cotton fabric enhances dye intensity and overall dyeing quality, consequently improving the colour fastness property of washing, rubbing, and perspiration. Additionally, the treated cotton fabric exhibits significant antimicrobial activity against common bacteria, highlighting the potential of Lotus seed-derived colourants and chitosan mordant in the development of sustainable and antimicrobial textiles. The future scope lies in optimizing the integration of Lotus seed-derived colourants and chitosan mordant for enhanced sustainability and antimicrobial efficacy in textile applications, leveraging advancements in dyeing technology and antimicrobial formulation techniques.

Glycolysis and Automated Plaque Regrowth Method for Evaluation of Antimicrobial Performance.

This study explored the potential of a new in vitro method in evaluating antiplaque benefits from five sets of antimicrobial systems including cetylpyridinium chloride (CPC), stannous fluoride (SnF2), Listerine essential oil mouthwashes (+/- alcohol), zinc chloride (ZnCl2), and sodium fluoride. (NaF). Gingival dental plaque was collected and propagated using sterilized tryptic soy broth and sucrose, and then allocated into separate glycolysis and regrowth recipes for antiplaque evaluations. Glycolysis measurements (in duplicate) were recorded via pH microelectrode on plaque-treatment samples thermomixed (1200 rpm, 37 °C) for 4 h. For plaque regrowth, optical densities (in duplicate) were automatically collected on plaque-treatment samples using a microplate reader (linear shaking, 37 °C) from baseline to 4 h. Calculations of percent change in pH and optical density were performed and analyzed for each set of antimicrobial treatment groups. Statistical analysis (one-way ANOVA, Student-Newman-Keuls stepwise comparison tests) revealed dose responses and significant differences (p < 0.05) among treatment groups, including between negative and clinically relevant positive controls. This lab method produces results consistent with published clinical observations. This glycolysis and plaque growth method is sensitive to antimicrobial mechanisms of action, and may offer a convenient and clinically relevant screening tool in the evaluation of putative antimicrobial agents and formulations.

Exploring the structure and dynamics of a fluorescent schiff base (1E,1′E)-1,1′-(1,4-phenylene) bis(N-(4-chlorophenyl) methamine: Synthesis, spectroscopic analysis, thermal, electronic and crystallographic study with biological applications

Schiff bases have emerged as attractive biological agents with a wide range of uses due to the extraordinary physical, chemical, and pharmacological characteristics that they possess. This study focuses on the effective synthesis of a Schiff base that is produced from 4-chloroaniline and terephthaldehyde. The success of this synthesis is supported by a variety of spectroscopic methods and Single crystal XRD analysis. The chemical that was synthesised had significant fluorescence qualities, with measured values at 457.13, 481.49, and 524.15 nm, highlighting the fact that it has the potential to be utilised in a variety of applications within the field. Using thermogravimetric analysis, the thermal stability of the compound was studied, which revealed an excellent stability at 399 °C. Thermal stability is an essential component of compound usefulness. Molecular insights were obtained by the utilisation of Density Functional Theory, which revealed an energy gap of 1.70 electron volts (eV) and electrophilic behaviour in certain atoms. The distribution of charges was brought to light through the use of Mulliken charges and molecular electrostatic potential analysis, which brought attention to the distinctive qualities of the subject molecule. An examination of the electron localization function revealed that the electron density inside carbon, nitrogen, and chlorine atoms had been delocalized. Additionally, the localised orbital locator wave function and reduced density gradient maps offered vital insights into the non-covalent interactions that were taking place within the system under investigation. In the course of the evaluation of antimicrobial efficacy, it was discovered that the chemical exhibited more powerful antibacterial activity against gram-positive B. subtilis than the conventional antibiotic amoxicillin. The antibacterial findings were further supported by molecular docking tests, which involved using particular proteins from the target species. These investigations showed that B. subtilis had a higher affinity for binding. These findings were further validated by molecular dynamic simulations. The synthesised chemical was subjected to in silico toxicity assessment using seven models, which demonstrated its non-irritating properties on the skin and eyes. The extensive analysis that is given here lays the groundwork for more targeted research on novel antibacterial drugs, with a particular focus on the safety, molecular interactions, and effectiveness of these compounds. As a result of the compound's potential applicability in biocompatible antimicrobial formulations, it is a viable candidate for improving the development of antibacterial medicines that are both effective and safe.

Polycomplexes to modulate bactericidal activity of cetylpyridinium bromide

Cetylpyridinium bromide, a quaternary ammonium surfactant, was electrostatically complexed with an excess of anionic polymers such as biodegradable sodium alginate or non-biodegradable sodium polyacrylate. The binding of surfactant with alginate delivered polymer–surfactant complexes capable of killing both more surfactant-sensitive Escherichia coli and less surfactant-sensitive Pseudomonas aeruginosa bacteria, while the binding with acrylate gave complexes active only against Escherichia coli. The results obtained show a way for adjustment of the antimicrobial formulation to a specific pathogen to be destroyed.

Inclusion complex of ionic liquid 1-dodecylpyridinium tetrafluoroborate with sulfobutyl ether-β-cyclodextrin: Preparation and characterization

In this article an inclusion complex of hydrophobic ionic liquid 1-dodecylpyridinium tetrafluoroborate (PyrC12-BF4) and sodium salt of sulfobutyl ether β-cyclodextrin (SB-β-CD) has been synthesized and studied using NMR spectroscopy, UV–Vis spectroscopy, FT-IR, TGA, DSC and XRD. The results of 1H NMR study revealed physicochemical interactions between the hydrophobic alkyl chain of PyrC12-BF4 and protons of the inner cavity of SB-β-CD, as well as between the CH protons of pyridinium cation and the polar SB-β-CD groups. The formation of an inclusion complex has also been revealed by Wilhelmy plate method. The binding constant of the SB-β-CD/PyrC12-BF4 complex determined by the method of Higuchi and Connors was found to be 1210 M–1. According to DSC analysis data, only one endothermic peak is observed in the thermogram of the SB-β-CD/PyrC12-BF4 inclusion complex, thus confirming the formation of a new supramolecular system. Additional characterization methods such as thermal mass spectroscopy and TEM were also applied for characterization of the synthesized complex. Complexation of long-chain pyridinium salt with SB-β-CD can be an efficient approach for the preparation of new antimicrobial formulations with reduced toxicity.