Unveiling Versatile Applications and Toxicity Considerations of Graphitic Carbon Nitride.

Metal-free, low-cost, organic photocatalytic graphitic carbon nitride (g-C3N4) has become a promising and impressive material in numerous scientific fields due to its unique physical and chemical properties. As a semiconductor with a suitable band gap of ~2.7 eV, g-C3N4 is an active photocatalytic material even after irradiation with visible light. However, information regarding the toxicity of g-C3N4 is not extensively documented and there is not a comprehensive understanding of its potential adverse effects on human health or the environment. In this context, the term "toxicity" can be perceived in both a positive and a negative light, depending on whether it serves as a benefit or poses a potential risk. This review shows the applications of g-C3N4 in sensorics, electrochemistry, photocatalysis, and biomedical approaches while pointing out the potential risks of its toxicity, especially in human and environmental health. Finally, the future perspective of g-C3N4 research is addressed, highlighting the need for a comprehensive understanding of the toxicity of this material to provide safe and effective applications in various fields.

The Influence of Mesotrione on Human Colorectal Adenocarcinoma Cells and Possibility of Its Toxicity Mitigation by Cichoric Acid.

Mesotrione, as a widely used herbicide, is present in the environment in detectable amounts, causing serious damage. Here, we aimed to investigate the effect of mesotrione on Caco-2 cells and the possibility of its toxicity mitigation by cichoric acid. Therefore, we analyzed the cytotoxicity of both these compounds and the selected oxidative stress parameters, apoptosis and interaction of both the tested compounds with the cell membrane and their accumulation within the cells. In cytotoxicity studies, the stimulating activity of mesotrione was observed, and simultaneously, the inhibitory effect of cichoric acid was noticed. This effect was related to the results of oxidative stress analysis and apoptosis measurements. The activity level of key enzymes (glutathione peroxidase, catalase and superoxide dismutase) in Caco-2 cells exposed to cichoric acid was higher as compared to that of the control. The treatment with mesotrione did not induce apoptosis in the Caco-2 cells. The penetration of the studied compounds into the Caco-2 cells was measured by using an HPLC methodology, and the results indicate mesotrione's high penetration capacity. The distribution of charge on the surface of the cell membranes changed under the influence of both compounds. Considering the mutual interactions of beneficial and potentially toxic food ingredients, it should be noted that, despite the observed favorable trend, cichoric acid is not able to overcome the toxic and cancer-stimulating effects of this pesticide.

Electrochemical Impedance Spectroscopy for the Sensing of the Kinetic Parameters of Engineered Enzymes.

The study presents a promising approach to enzymatic kinetics using Electrochemical Impedance Spectroscopy (EIS) to assess fundamental parameters of modified enteropeptidases. Traditional methods for determining these parameters, while effective, often lack versatility and convenience, especially under varying environmental conditions. The use of EIS provides a novel approach that overcomes these limitations. The enteropeptidase underwent genetic modification through the introduction of single amino acid modifications to assess their effect on enzyme kinetics. However, according to the one-sample t-test results, the difference between the engineered enzymes and hEKL was not statistically significant by conventional criteria. The kinetic parameters were analyzed using fluorescence spectroscopy and EIS, which was found to be an effective tool for the real-time measurement of enzyme kinetics. The results obtained through EIS were not significantly different from those obtained through traditional fluorescence spectroscopy methods (p value >> 0.05). The study validates the use of EIS for measuring enzyme kinetics and provides insight into the effects of specific amino acid changes on enteropeptidase function. These findings have potential applications in biotechnology and biochemical research, suggesting a new method for rapidly assessing enzymatic activity.

Alteration of zeta potential and cell viability in rat-derived L6 skeletal muscle cells and H9c2 cardiomyocytes: A study with submicron polystyrene particles.

BACKGROUND: Microand nanoplastics pollution can cause substantial damage to ecosystems. Since scientists have focused mainly on their impact on aquatic environments, less attention has been paid to the accumulation of polymer particles in terrestrial organisms. OBJECTIVES: We checked if submicron (<5 mm) polystyrene (PS) particles, which can accumulate in living organisms, lead to changes in the physicochemical properties of mammalian cell membranes. MATERIAL AND METHODS: The influence of submicron PS particles on the properties of rat-derived L6 myocytes and H9c2 cardiomyocytes was analyzed. Non-functionalized and amine-functionalized PS particles of 100 nm and 200 nm in diameter were used. The MTT assay was performed to evaluate the viability of the polymers-treated cells. The effect of short (6 h) and prolonged (48 h) incubation with different concentrations of PS particles on the cell's zeta (ζ) potential was examined with the electrophoretic light scattering technique (ELS). Polystyrene particles' physicochemical characteristics (size and stability) were performed using dynamic light scattering (DLS) and electrophoretic light scattering methods. RESULTS: The results show that submicron PS particles affect cell viability and cause changes in the physiochemical parameters of rat cell membranes. Differences were observed depending on the origin of the cells. We observed doseand time-dependent alterations in the studied parameters after submicron PS particle incubation in L6 myotubes and H9c2 cardiomyocytes. CONCLUSIONS: The size and modification of PS particle surfaces determine the extent to which they affect the analyzed properties of rat cardiomyocytes and myocytes membranes.

Cellular stress responses as modulators of drug cytotoxicity in pharmacotherapy of glioblastoma.

Despite the extensive efforts to find effective therapeutic strategies, glioblastoma (GBM) remains a therapeutic challenge with dismal prognosis of survival. Over the last decade the role of stress responses in GBM therapy has gained a great deal of attention, since depending on the duration and intensity of these cellular programs they can be cytoprotective or promote cancer cell death. As such, initiation of the UPR, autophagy or oxidative stress may either impede or facilitate drug-mediated cell killing. In this review, we summarize the mechanisms that regulate ER stress, autophagy, and oxidative stress during GBM development and progression to later discuss the involvement of these stress pathways in the response to different treatments. We also discuss how a precise understanding of the molecular mechanisms regulating stress responses evoked by different pharmacological agents could decisively contribute to the design of novel and more effective combinational treatments against brain malignancies.

Selected Fungicides as Potential EDC Estrogenic Micropollutants in the Environment.

An increasing level of pesticide exposition is being observed as a result of the consumption of large amounts of fruits, vegetables and grain products, which are key components of the vegetarian diet. Fungicides have been classified as endocrine-disrupting compounds, but their mechanisms of action have not yet been clarified. The effect of boscalid (B), cyprodinil (C) and iprodione (I) combined with Tamoxifen (T) and 17ß-estradiol (E2) on cell viability, cell proliferation, reporter gene expression, ROS content, the cell membrane's function, cell morphology and antioxidant enzymes gene expression in MCF-7 and T47D-KBluc cell lines were investigated. The cell lines were chosen due to their response to 17ß -estradiol. The selected fungicides are commonly used in Poland to protect crops against fungi. Our results revealed that the studied fungicides caused significant increases in cell viability and proliferation, and estrogenic activity was present in all studied compounds depending on their concentrations. Oxidative stress activated uncontrolled cancer cell proliferation by inducing ROS production and by inhibiting antioxidant defense. Our findings verify that the studied fungicides could possibly exhibit endocrine-disrupting properties and exposure should be avoided.

Structures, Antioxidant Properties, and Antimicrobial Properties of Eu(III), Gd(III), and Dy(III) Caffeinates and p-Coumarates.

In this study, we investigated the structures of lanthanide (Eu(III), Dy(III), and Gd(III)) complexes with p-coumaric (p-CAH2) and caffeic (CFAH3) acids using the FTIRKBr, FTIRATR, and Raman spectroscopic methods. The compositions of the solid phase caffeinates and p-coumarates were obtained on the basis of the amounts of hydrogen and carbon determined using an elemental analysis. The degree of hydration and the thermal decomposition of each compound were examined via a thermal analysis of TG, DTG, and DSC. Antioxidant spectroscopic tests were performed using the DPPH (1,1-diphenyl-2-picrylhydrazyl radical), FRAP (ferric reducing antioxidant activity), and ABTS (2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (diammonium salt radical cation) methods. The antimicrobial activity of each compound against Escherichia coli, Bacillus subtilis, and Candida albicans was investigated. The electrical properties of the liposomes which mimicked the microbial surfaces formed in the electrolyte containing the tested compounds were also investigated. The above biological properties of the obtained complexes were compared with the activities of p-CAH2 and CFAH3. The obtained data suggest that lanthanide complexes are much more thermally stable and have higher antimicrobial and antioxidant properties than the ligands (with the exception of CFAH3 in the case of antioxidant activity tests). The Gd(III) complexes revealed the highest biological activity among the studied lanthanide complexes.

Exposure to polystyrene nanoparticles leads to changes in the zeta potential of bacterial cells.

Polymer molecules, the main components of plastics, are an emerging pollutants in various environmental compartments (water, air, soil) that may induce several ecotoxicological effects on live organisms. Therefore, understanding how plastic particles interact with bacterial cell membranes is crucial in analysing their associated risks in ecosystems and human microbiota. However, relatively little is known about the interaction between nanoplastics and bacteria. The present work focuses on Staphylococcus aureus and Klebsiella pneumoniae, representing the Gram-positive and Gram-negative bacteria respectively, exposed to 100 nm diameter polystyrene nanoparticles (PS NPs). The nanoparticles attach to the cells' membranes of both bacteria, changing their electrical charge, but without the effect of killing the cells. PS NPs caused a change in zeta potential values (both species of bacterial strains), dependent on particle concentration, pH, as well as on exposure time of bacteria to them. Through the application of AFM and FTIR techniques, the presence of PS NPs on bacterial surfaces was detected, suggesting the affinity of the particles to bacterial components, but without any changes in the morphology of the tested bacteria. The zeta potential can be more widely used in the study of interactions between nanostructures and cells.

Direct electrochemical determination of environmentally harmful pharmaceutical ciprofloxacin in 3D printed flow-through cell.

Rising amounts of antibiotic residues in wastewater cause serious problems including increased bacterial resistance. Wastewater treatment plants (WWTPs) do not, in the case of new, modern pharmaceuticals, ensure their complete removal. Ciprofloxacin (CIP) is one of many micropollutants that partially pass through WWTPs, implying that its monitoring is essential for the assessment of the water quality. In real sewage systems, the determination of CIP needs to be performed under flowing conditions, which calls for the deployment of inexpensive, robust, and easily integrable approaches such as electrochemical techniques. However, to the best of our knowledge, there is no report on the electrochemical determination of CIP in a flowing matrix. To bridge this gap, we perform here cyclic and square-wave voltammetric sensing study of CIP employing boron-doped diamond screen printed electrodes in a custom-made 3D printed flow-through cell to mimic conditions in real sewage systems. An irreversible two-step oxidation of CIP is demonstrated, with the first step providing clear Faradaic response as analytically relevant signal. This response was found to scale with the sample flow rate according to the prediction given by Levich equation. Our work provides an in-depth inspection of the electrochemical response of CIP under controlled-convection conditions, which is an essential prerequisite for monitoring this antibiotic in real flowing sewage systems.

The Phenotype of the Adipocytes Derived from Subcutaneous and Visceral ADMSCs Is Altered When They Originate from Morbidly Obese Women: Is There a Memory Effect?

Adipose tissue is an abundant source of mesenchymal stem cells (ADMSCs). Evidence has suggested that depot-specific ADMSCs (obtained from subcutaneous or visceral adipose tissue-subADMSCs or visADMSCs, respectively) account for differential responses of each depot to metabolic challenges. However, little is known about the phenotype and changes in metabolism of the adipocytes derived from ADMSCs of obese individuals. Therefore, we investigated the phenotypic and metabolic characteristics, particularly the lipid profile, of fully differentiated adipocytes derived from ADMSCs of lean and obese (with/without metabolic syndrome) postmenopausal women. We observed a depot-specific pattern, with more pronounced changes present in the adipocytes obtained from subADMSCs. Namely, chronic oversupply of fatty acids (present in morbid obesity) triggered an increase in CD36/SR-B2 and FATP4 protein content (total and cell surface), which translated to an increased LCFA influx (3H-palmitate uptake). This was associated with the accumulation of TAG and DAG in these cells. Furthermore, we observed that the adipocytes of visADMSCs origin were larger and showed smaller granularity than their counterparts of subADMSCs descent. Although ADMSCs were cultured in vitro, in a fatty acids-deprived environment, obesity significantly influenced the functionality of the progenitor adipocytes, suggesting the existence of a memory effect.

The Effect of Submicron Polystyrene on the Electrokinetic Potential of Cell Membranes of Red Blood Cells and Platelets.

In recent years, many scientists have studied the effects of polymer micro- and nanostructures on living organisms. As it turns out, plastic can be a component of the blood of livestock, eaten by humans around the globe. Thus, it seems important to investigate possible changes in the physicochemical parameters and morphology of the cell membranes of blood morphotic elements (red blood cells and platelets) under the influence of polymer particles. The article presents research in which cell membranes were exposed to plain polystyrene (PS) and amino-functionalized polystyrene (PS-NH2) of two different sizes. The polymers were characterized by infrared spectroscopy and dynamic light-scattering methods. To analyze possible changes caused by polymer exposure in the structure of the membranes, their zeta potentials were measured using the electrophoretic light-scattering technique. The concentration of the polymers, as well as the exposure time, were also taken into the consideration during the research. Based on the obtained results, we concluded that 100 and 200 nm PS, as well as 100 nm PS-NH2, internalize into the cells. On the contrary, 200 nm PS-NH2 particles attach to cell membranes. Our study clearly shows that particle size and surface chemistry determine the interaction with biological membranes.

The influence of the pH on the incorporation of caffeic acid into biomimetic membranes and cancer cells.

Caffeic acid (CA) is a phenolic compound synthesized by all plant species. It constitutes the main hydroxycinnamic acid found in human diet and presents a variety of beneficial effects including anticancer activity. Current data suggests essential role of the interplay between anticancer drugs and the cell membrane. Given this, biophysical interactions between CA and cancer cells or biomimetic membranes were investigated. Glioblastoma cell line U118MG and colorectal adenocarcinoma cell line DLD-1, as well as lipid bilayers and liposomes, were used as in vitro models. Electrophoretic light scattering was used to assess the effect of CA on the surface charge of cancer cells and liposomal membranes. Electrochemical impedance spectroscopy was chosen to evaluate CA-dependent modulatory effect on the electrical capacitance and electrical resistance of the bilayers. Our results suggest that CA fulfills physicochemical criteria determining drug-like properties of chemical compounds, and may serve as a potential cytostatic agent in cancer treatment.

Electrical Properties of Model Lipid Membranes.

Biological membranes are essential components of the living systems, and processes occurring with their participation are related mainly to electric phenomena such as signal transduction, existence of membrane potentials, and transport through the membrane [...].

A Preliminary Study of the Effect of Quercetin on Cytotoxicity, Apoptosis, and Stress Responses in Glioblastoma Cell Lines.

A growing body of evidence indicates that dietary polyphenols show protective effects against various cancers. However, little is known yet about their activity in brain tumors. Here we investigated the interaction of dietary flavonoid quercetin (QCT) with the human glioblastoma A172 and LBC3 cell lines. We demonstrated that QCT evoked cytotoxic effect in both tested cell lines. Microscopic observations, Annexin V-FITC/PI staining, and elevated expression and activity of caspase 3/7 showed that QCT caused predominantly apoptotic death of A172 cells. Further analyses confirmed enhanced ROS generation, deregulated expression of SOD1 and SOD2, depletion of ATP levels, and an overexpression of CHOP, suggesting the activation of oxidative stress and ER stress upon QCT exposure. Finally, elevated expression and activity of caspase 9, indicative of a mitochondrial pathway of apoptosis, was detected. Conversely, in LBC3 cells the pro-apoptotic effect was observed only after 24 h incubation with QCT, and a shift towards necrotic cell death was observed after 48 h of treatment. Altogether, our data indicate that exposure to QCT evoked cell death via activation of intrinsic pathway of apoptosis in A172 cells. These findings suggest that QCT is worth further investigation as a potential pharmacological agent in therapy of brain tumors.

Caffeic Acid/Eu(III) Complexes: Solution Equilibrium Studies, Structure Characterization and Biological Activity.

Caffeic acid (CFA) is one of the various natural antioxidants and chemoprotective agents occurring in the human diet. In addition, its metal complexes play fundamental roles in biological systems. Nevertheless, research on the properties of CFA with lanthanide metals is very scarce, and little to no chemical or biological information is known about these particular systems. Most of their properties, including their biological activity and environmental impact, strictly depend on their structure, stability, and solution behaviour. In this work, a multi-analytical-technique approach was used to study these relationships for the Eu(III)/CFA complex. The synthesized metal complex was studied by FT-IR, FT-Raman, elemental, and thermal (TGA) analysis. In order to examine the chemical speciation of the Eu(III)/CFA system in an aqueous solution, several independent potentiometric and spectrophotometric UV-Vis titrations were performed at different M:L (metal:ligand) and pH ratios. The general molecular formula of the synthesized metal complex in the solid state was [Eu(CFA)3(H2O)3]∙2H2O (M:L ratio 1:3), while in aqueous solution the 1:1 species were observed at the optimum pH of 6 ≤ pH ≤ 10, ([Eu(CFA)] and [Eu(CFA)(OH)]-). These results were confirmed by 1H-NMR experiments and electrospray-ionization mass spectrometry (ESI-MS). To evaluate the interaction of Eu(III)/CFA and CFA alone with cell membranes, electrophoretic mobility assays were used. Various antioxidant tests have shown that Eu(III)/CFA exhibits lower antioxidant activity than the free CFA ligand. In addition, the antimicrobial properties of Eu(III)/CFA and CFA against Escherichia coli, Bacillus subtilis and Candida albicans were investigated by evaluation of the minimum inhibitory concentration (MIC). Eu(III)/CFA shows higher antibacterial activity against bacteria compared to CFA, which can be explained by the highly probable increased lipophilicity of the Eu(III) complex.

Hospital Wastewater-Source of Specific Micropollutants, Antibiotic-Resistant Microorganisms, Viruses, and Their Elimination.

Municipal wastewaters can generally provide real-time information on drug consumption, the incidence of specific diseases, or establish exposure to certain agents and determine some lifestyle consequences. From this point of view, wastewater-based epidemiology represents a modern diagnostic tool for describing the health status of a certain part of the population in a specific region. Hospital wastewater is a complex mixture of pharmaceuticals, illegal drugs, and their metabolites as well as different susceptible and antibiotic-resistant microorganisms, including viruses. Many studies pointed out that wastewater from healthcare facilities (including hospital wastewater), significantly contributes to higher loads of micropollutants, including bacteria and viruses, in municipal wastewater. In addition, such a mixture can increase the selective pressure on bacteria, thus contributing to the development and dissemination of antimicrobial resistance. Because many pharmaceuticals, drugs, and microorganisms can pass through wastewater treatment plants without any significant change in their structure and toxicity and enter surface waters, treatment technologies need to be improved. This short review summarizes the recent knowledge from studies on micropollutants, pathogens, antibiotic-resistant bacteria, and viruses (including SARS-CoV-2) in wastewater from healthcare facilities. It also proposes several possibilities for improving the wastewater treatment process in terms of efficiency as well as economy.

The Pro-Apoptotic Effect of Silica Nanoparticles Depends on Their Size and Dose, as Well as the Type of Glioblastoma Cells.

Despite intensive investigations, nanoparticle-induced cellular damage is an important problem that has not been fully elucidated yet. Here, we report that silica nanoparticles (SiNPs) demonstrated anticancer influence on glioblastoma cells by the induction of apoptosis or necrosis. These effects are highly cell type-specific, as well as dependent on the size and dose of applied nanoparticles. Exposure of LN-18 and LBC3 cells to different sizes of SiNPs-7 nm, 5-15 nm, or 10-20 nm-at dosages, ranging from 12.5 to 1000 µg/mL, for 24 and 48 h reduced the viability of these cells. Treatment of LN-18 and LBC3 cells with 7 nm or 10-20 nm SiNPs at doses ≥50 µg/mL caused a strong induction of apoptosis, which is connected with an increase of intracellular reactive oxygen species (ROS) production. The 5-15 nm SiNPs exhibited distinct behavior comparing to silica nanoparticles of other studied sizes. In contrast to LBC3, in LN-18 cells exposed to 5-15 nm SiNPs we did not observe any effect on apoptosis. These nanoparticles exerted only strong necrosis, which was connected with a reduction in ROS generation. This suggests that SiNPs can trigger different cellular/molecular effects, depending on the exposure conditions, the size and dose of nanoparticles, and cell type of glioblastoma.

Effect of Selected Anionic and Cationic Drugs Affecting the Central Nervous System on Electrical Properties of Phosphatidylcholine Liposomes: Experiment and Theory.

Interactions between phospholipid membranes and selected drugs affecting the central nervous system (CNS) were investigated. Small, unilamellar liposomes were used as biomimetic cell membrane models. Microelectrophoretic experiments on two-component liposomes were performed using the electrophoretic light scattering technique (ELS). The effect of both positively (perphenazine, PF) and negatively (barbituric acid, BA) charged drugs on zwitterionic L-α-phosphatidylcholine (PC) membranes were analyzed. Experimental membrane surface charge density (δ) data were determined as a function of pH. Quantitative descriptions of the adsorption equilibria formed due to the binding of solution ions to analyzed two-component membranes are presented. Binding constants of the solution ions with perphenazine and barbituric acid-modified membranes were determined. The results of our research show that both charged drugs change surface charge density values of phosphatidylcholine membranes. It can be concluded that perphenazine and barbituric acid are located near the membrane surface, interacting electrostatically with phosphatidylcholine polar heads.

Molecular and Cellular Effects of Chemical Chaperone-TUDCA on ER-Stressed NHAC-kn Human Articular Chondrocytes Cultured in Normoxic and Hypoxic Conditions.

Osteoarthritis (OA) is considered one of the most common arthritic diseases characterized by progressive degradation and abnormal remodeling of articular cartilage. Potential therapeutics for OA aim at restoring proper chondrocyte functioning and inhibiting apoptosis. Previous studies have demonstrated that tauroursodeoxycholic acid (TUDCA) showed anti-inflammatory and anti-apoptotic activity in many models of various diseases, acting mainly via alleviation of endoplasmic reticulum (ER) stress. However, little is known about cytoprotective effects of TUDCA on chondrocyte cells. The present study was designed to evaluate potential effects of TUDCA on interleukin-1ß (IL-1ß) and tunicamycin (TNC)-stimulated NHAC-kn chondrocytes cultured in normoxic and hypoxic conditions. Our results showed that TUDCA alleviated ER stress in TNC-treated chondrocytes, as demonstrated by reduced CHOP expression; however, it was not effective enough to prevent apoptosis of NHAC-kn cells in either normoxia nor hypoxia. However, co-treatment with TUDCA alleviated inflammatory response induced by IL-1ß, as shown by down regulation of Il-1ß, Il-6, Il-8 and Cox2, and increased the expression of antioxidant enzyme Sod2. Additionally, TUDCA enhanced Col IIα expression in IL-1ß- and TNC-stimulated cells, but only in normoxic conditions. Altogether, these results suggest that although TUDCA may display chondoprotective potential in ER-stressed cells, further analyses are still necessary to fully confirm its possible recommendation as potential candidate in OA therapy.

Electrophoretic Light Scattering and Electrochemical Impedance Spectroscopy Studies of Lipid Bilayers Modified by Cinnamic Acid and Its Hydroxyl Derivatives.

Pharmacological efficiency of active compounds is largely determined by their membrane permeability. Thus, identification of drug-membrane interactions seems to be a crucial element determining drug-like properties of chemical agents. Yet, knowledge of this issue is still lacking. Since chemoprevention based on natural compounds such as cinnamic acid (CinA), p-coumaric acid (p-CoA) and ferulic (FA) is becoming a strong trend in modern oncopharmacology, determination of physicochemical properties of these anticancer compounds is highly important. Here, electrophoretic light scattering and impedance spectroscopy were applied to study the effects of these phenolic acids on electrical properties of bilayers formed from 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), 1,2-diacyl-sn-glycero-3-phospho-l-serine (PS) or DOPC-PS mixture. After phenolic acid treatment, the negative charge of membranes increased in alkaline pH solutions, but not in acidic ones. The impedance data showed elevated values of both the electrical capacitance and the electrical resistance. We concluded that at acidic pH all tested compounds were able to solubilize into the membrane and permeate it. At neutral and alkaline pH, the CinA could be partially inserted into the bilayers, whereas p-CoA and FA could be anchored at the bilayer surface. Our results indicate that the electrochemical methods might be crucial for predicting pharmacological activity and bioavailability of phenolic acids.