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Resistant biofilms formed by Staphylococcus aureus on medical devices pose a constant medical threat. A promising alternative to tackle this problem is photodynamic inactivation (PDI). This study focuses on a polyurethane (PU) material with an antimicrobial surface consisting of a composite based on silicate, polycation, and erythrosine B (EryB). The composite was characterized using X-ray diffraction and spectroscopy methods. Anti-biofilm effectiveness was determined after PDI by calculation of CFU mL−1. The liquid PU precursors penetrated a thin silicate film resulting in effective binding of the PU/silicate composite and the PU bulk phases. The incorporation of EryB into the composite matrix did not significantly alter the spectral properties or photoactivity of the dye. A green LED lamp and laser were used for PDI, while irradiation was performed for different periods. Preliminary experiments with EryB solutions on planktonic cells and biofilms optimized the conditions for PDI on the nanocomposite materials. Significant eradication of S. aureus biofilm on the composite surface was achieved by irradiation with an LED lamp and laser for 1.5 h and 10 min, respectively, resulting in a 10,000-fold reduction in biofilm growth. These results demonstrate potential for the development of antimicrobial polymer surfaces for modification of medical materials and devices.

Erythrosine B (EB) is a food colorant and antiviral xanthene dye that is widely used as a color additive in pharmaceutical and cosmetic industries. Its application as a sensor for spectrophotometric measurement of amine-based pharmaceuticals offers several benefits due to its availability, low cost, quick labeling, and high sensitivity. In the present study, a quick, sensitive and simple green spectrophotometric method has been developed to assay Bromhexine Hydrochloride (BMH) in pure form and its pharmaceutical formulation. The spectrophotometric methodology reveals complex development between the drug and erythrosine B at 556 nm at pH 3.6. The spectrophotometric absorbance-concentration curve is linear over the ranges (1.0–9.0 μg mL −1 ) with low detection limit 0.199 μg mL −1 and low quantification limit 0.605 μg mL −1 . The developed approach was assessed for linearity, accuracy, precision, limits of detection, and limits of quantitation in compliance with International Council for Harmonisation validation recommendations. Lastly, the suggested approach has been successfully implemented to quantify the cited medication colorimetrically in its dosage form with excellent recoveries. Also, the greenness of the suggested approach was measured by some of the recent green analytical measures as applications to our presented methodology show further access to this study.

Abstract This study aimed to investigate the cytotoxic effects of erythrosine-B (ErB), saccharin, and sorbic acid (SA) on human breast adenocarcinoma (MCF-7) and glioblastoma (U87-MG) cell lines and the expression levels of DNA methyltransferases (DNMT1, DNMT3a) and genes involved in the apoptotic process (Bax, Bcl-2). After treatment, RT-QPCR was used to analyse the gene expression levels. In addition, the suppressive effects of different doses of these additives on cell proliferation on MCF-7 and U87 MG cells were determined by the MTT method. Our findings show that saccharin, SA, and ErB significantly up-regulated DNMT1 and DNMT3a gene expression compared to the control group. A dose-dependent increase in Bax and Bcl-2 gene expression was observed. This, when considered together with the cytotoxic/genotoxic effects observed in the study, suggests that the substance may simultaneously trigger both pro- and anti-apoptotic signals. This dual regulation reflects the complexity of the cellular response. These results suggest that saccharin, SA, and ErB may have an effect on both epigenetic regulations and apoptotic mechanisms. Graphical Abstract Graphical Abstract

Organic transformations play a vital role in enhancing the scope of pharmaceuticals through the design and development of small bioactive molecules. The facile synthesis of these molecules is more feasible in the presence of catalysts. Nowadays, photocatalysts are quickly replacing the earlier ones due to their eco-friendlier nature and by following the rules of green chemistry. Herein, we are proposing the design and development of a covalent organic framework TBP-SE through the loading of erythrosine B on sulfone-conjugated 2-D pyrene assembly ( TBP-S ). TBP-SE is a highly crystalline (65.9%) COF with good photostability and fast charge separation (band gap, 2.1 eV). In the photocatalytic study, the TBP-SE is observed as a promising heterogeneous catalyst for efficient cyclization of thioamide to 1,2,4-thiadiazole in high yield (96.5%) along with promising recyclability (5 times).

Food colorants are commonly used as excipients in pharmaceutical and nutraceutical fields, but they have a wide range of other potential applications, for instance, as cytotoxic drugs or mediators of physical antimicrobial treatments. The photodynamic antibacterial activity of several edible food colorants is reported here, including E127, E129, E124, E122, E133, and E150a, alongside Rhein, a natural lipophilic antibacterial and anticancer compound found in medicinal plants. Minimal inhibitory concentration (MIC) values for S. aureus and E. coli showed that E127 and Rhein were effective against both bacteria, while other colorants exhibited low activity against E. coli. In some cases, dark pre-incubation of the colorants with Gram-positive S. aureus increased their photodynamic activity. Adding Rhein to E127 increased the photodynamic activity of the latter in a supportive mode. Optional sensing mechanism pathways of combined E127/Rhein action were suggested. The antibacterial activity of the studied colorants can be ranged as follows: E127/Rhein >> E127 >> E150a > E122 > E124 >> E129 ≈ E133. E127 was also found to exhibit photodynamic properties. Short ultrasonic treatment before illumination caused intensification of E127 photodynamic activity against E. coli when applied alone and especially in combination with Rhein. Food colorants exhibiting photo- and sonodynamic properties may have good potential in food preservation.

The visible light-assisted photocatalysis approach allows more sustainable and atom-economical C–H bond arylation processes. The polymer-based photocatalysts are an attractive choice because of their variable design and development feasibility as well as effective catalytic applications. In the present work, by following the basic principles of green chemistry, we have chosen an environmentally friendly and biologically suitable chemical i.e. Erythrosine B as a unit molecule for the generation of photocatalyst EP (C 20 H 8 O 5 S 4 ). The generation of EP has been performed via a one-pot solvothermal reaction of Erythrosine B with sulfur powder. The structural analysis of the EP evidence the generation of an interesting example 2D-polymeric assembly where disulfide (–S–S–) units are acting as linkers and show high thermal stability up to 800 °C (39.9% left as a residue). The low optical band gap of 2.08 eV and electrochemical band gap of 2.09 eV favors its catalytic applicability. The catalytic investigation reveals excellent applicability of EP in C–H arylation (yield 98.5% & selectivity 99%).

Backround: The agr (accessory gene regulator) quorum sensing (QS) system of Staphylococcus aureus participates significantly in its virulence and biofilm formation—either through its activation or suppression. The aim of this study was to investigate the impact of photoactive nanomaterials that have been functionalized with erythrosine B (EryB) on the modulation of this agr QS system on three methicillin-resistant S. aureus (MRSA). Methods: The functionality of the agr system was determined by the CAMP test and by quantitative PCR (qPCR) to analyze the expression of the hld gene, which is located within the RNAIII and encodes δ-hemolysin. The biofilm was evaluated by crystal violet assay and fluorescence microscopy. The anti-biofilm activity was determined by calculating the colony-forming units. The relative expression of the hld gene, determined by qPCR. Results: Using the CAMP test, S66 and S68 strains were found to be agr-positive, and strain S73 was agr-negative. The relative expression of the hld gene increased only in the agr-positive strains (600- and 1000-fold). In these strains, the biofilm was less compact compared to the dense biofilm formed by the agr-negative strain. The anti-biofilm effectiveness on the nanocomposite with EryB after irradiation reduced the growth of biofilm cells by 100- to 1000-fold compared to the biofilm on polyurethane alone. The qPCR results showed a significant decrease in the relative expression of the hld gene in the agr-positive strains after irradiation compared to the non-irradiated samples. Conclusions: These results suggest that photoactive nanocomposites with EryB can significantly reduce biofilm formed by MRSA strains, regardless of the functionality of the agr QS system.

The current article describes facile, selective and highly sensitive spectrofluorimetric methodology for the determination of Mirabegron (MBG). The approach originated from the drug’s reaction with Erythrosine B in an acidic buffered media leading to the production of a binary complex. This interaction caused a significant quenching in the intensity of the fluorescence of Erythrosine B at an emission wavelength ( ʎ em ) of 550 nm, following excitation ( ʎ ex ) at 520 nm. Key parameters of the procedure were optimized before constructing the calibration curve. A direct proportionality was obtained between the fluorescence quenching and MBG concentrations ranging from 0.05 to 1.2 µg/mL. Both limits of detection (LOD) and quantitation (LOQ) have been calculated to be 0.01 and 0.04 µg/mL, respectively. Implementing the demands set by the ICH, the developed technique was assessed to evaluate the level of accuracy, precision, and robustness. The suggested approach was employeds to determine the drug being studied in pharmaceutical tablets. Moreover, the suggested spectrofluorimetric method exhibited an elevated level of sensitivity, making it suited for accurately determining the mentioned drug in real plasma samples with outstanding recovery and a low relative standard deviation. The environmental sustainability of the proposed method was systematically evaluated through AGREE (Analytical Greenness Metric) and BAGI (Blue Applicability Grade Index) assessments, demonstrating superior eco-friendliness compared to conventional HPLC and electroanalytical techniques (AGREE score: 0.72 vs. 0.55–0.62). In addition to confirmation of the environmentally safety of the proposed approach, its blueness has been assessed using Blue Applicability Grade Index.

The demand for rapid, energy-efficient, and low-toxicity methods for synthesizing molecularly imprinted polymers (MIPs) is increasing, particularly for applications in environmental monitoring and green chemistry. In this context, the present work focuses on the development of a novel laser-assisted method for MIP synthesis, employing a visible laser (450 nm) and erythrosine B as a green photoinitiator. This visible-light approach enables fast and spatially controlled polymerization while avoiding the drawbacks of conventional methods (thermal heating, UV synthesis), such as the use of toxic initiators like AIBN and the need for UV shielding. MIPs were synthesized for bisphenol A and sulfamethoxazole, two emerging contaminants of significant environmental concern. The synthesis process was optimized for rapidity and scalability, and the resulting MIPs were integrated into a paper-based analytical device (MIP-PAD) for smartphone-assisted, on-site detection. The developed sensors exhibited excellent analytical performance, with recovery rates of 98.6% in tap water and 90.2% in river water and relative standard deviations (RSDs) below 1.88%. This study demonstrated a green, efficient, and highly controllable laser-assisted polymerization technique, offering a promising alternative to conventional MIP synthesis methods.

Due to the lack of other treatment options, a rebirth of polymyxins is urgently required. Colistin (also called polymyxin E) and polymyxin B are the only two examples of this antibiotic class that were effectively employed in such critical situations. In the present work, both of the two studied medications were quantified via a simple, green, and non-extracting spectrophotometric approach based on the formation of ion-pair complexes with Erythrosine B. Without using any organic solvents, the pink color of the created complexes was detected at wavelength = 558 nm. To achieve the highest intensity of absorbance, optimum conditions were established by the screening of many experimental factors such as pH, buffer volume, the volume of Erythrosine B, and the time consumed to undergo the reaction. For Colistin and Polymyxin B respectively, Beer-Lambert’s law was observed at the concentration ranges of 1–6, 1–9 µg mL− 1. The technique was approved and validated following ICH recommendations. Lastly, the suggested approach has been successfully implemented to quantify the cited medications colorimetrically, for the first time, in their parenteral dosage forms with excellent recoveries. Also, Content uniformity testing was implemented.