Search Results (1,359)

Advanced glycation end products (AGEs) are compounds that accumulate in hyperglycemic states, contributing significantly to the development of diabetes and its complications, including the exacerbation of periodontal disease. We hypothesized that AGEs affect the expression of inflammatory mediators in gingival cells, thus contributing to the increased severity of periodontitis observed in diabetic patients. Thus, we stimulated the gingival epithelial carcinoma-derived cell line, Ca9-22, with AGEs and examined their effect on the expression of prostaglandin E₂ (PGE₂) and its primary synthesizing enzyme, cyclooxygenase 2 (COX2), key inflammatory mediators in periodontitis. AGEs significantly increased the expression levels of COX2 (n = 6, p < 0.001) and the production of PGE₂ (n = 5, p < 0.05) compared to untreated control and bovine serum albumin (BSA) groups. The receptor for AGEs (RAGE) inhibitor FPS-ZM1 blocked the AGEs-stimulatory effects on COX2 (n = 7, p < 0.01), PGE₂ (n = 6, p < 0.001), and Toll-like receptor 4 (TLR4) expression (n = 7, p < 0.001). Furthermore, AGEs induced the phosphorylation of protein kinase C (p-PKC) via the TLR4 pathway (n = 7, p < 0.01). Crucially, AGEs enhanced NF-κB nuclear accumulation, which was inhibited by blocking either RAGE (n = 5, p < 0.0001) or TLR4 (n = 5, p < 0.0001). In conclusion, these findings demonstrate that AGEs increase PGE₂ production in Ca9-22 cells primarily through a signaling cascade involving RAGE and the TLR4-PKC-NF-κB pathway. Our results suggest TLR4 as a critical mediator that contributes to AGEs-induced inflammation. Full article

This paper proposes a method for E. coli detection in a microplate format using low-molecular-weight compounds that specifically interact with the lipopolysaccharides (LPSs) of E. coli cell walls. These compounds can amplify analytical signals by binding to multiple repeating cell surface structures, while the selectivity for E. coli is ensured by preliminary cultivation on selective media, such as Endo or MacConkey agar. 3-Aminophenylboronic acid (APBA) was selected as the binding reagent for detecting E. coli LPSs. Conjugates of streptavidin (STP) and bovine serum albumin (BSA) with APBA and conjugates of biotin and soybean trypsin inhibitor (STI) and BSA were synthesized. The conditions for the sequential formation of “sandwich” type complexes (BSA-APBA conjugate/E. coli/STP-APBA/STI–biotin/STP–peroxidase) and their colorimetric detection using chromogenic peroxidase substrate were determined. The detection limit was 3 × 10² cells/mL, and the range of quantitative determination covered five orders of magnitude—from 10³ to 10⁸ cells/mL. The developed assay was successfully tested using inactivated cells of pathogenic E. coli strains, confirming its potential for application. The assay was demonstrated to have universality, with the ability to detect E. coli, other bacterial pathogens, and LPS alone. This method could be adopted for the quantitative determination of different specific bacterial species using different selective media. Full article

A series of azide- and cyclooctyne-functionalized N-hydroxysuccinimidyl esters (NHS esters) and benzotriazolides were prepared and used as N-acylation reagents to obtain azide-(BSA-1) and cyclooctyne-functionalized bovine serum albumin proteins (BSA-2), fluorescein derivatives 5 and 6, and homobifunctional linkers 3 and 4. Strain-promoted azide-alkyne cycloaddition (SPAAC) and copper-catalyzed azide-alkyne cycloaddition (CuAAC) of azide-functionalized fluorescent probe 5 and alkyne-functionalized fluorescent probe 6 with complementary functionalized proteins BSA-2 and BSA-1 yielded fluorescent cycloadducts BSA-2-5 and BSA-1-6. These cycloadducts were used to determine the loading of BSA-1 and BSA-2 with the respective azido and cyclooctyne groups based on their molar absorbances and fluorescence intensities. Dimerization through covalent cross-linking of BSA was then performed by SPAAC between azide-functionalized BSA-1 and cyclooctyne-functionalized BSA-2, and by treating BSA-1 and BSA-2 with 0.5 equiv. of complementary bis-cyclooctyne linker 4 and bis-azide linker 3. Although the formation of covalent dimers BSA-1-2-BSA, BSA-1-6-1-BSA, and BSA-2-5-2-BSA was detected by SDS-PAGE analysis, this was a minor process, and most of the functionalized BSA did not form covalent dimers. Full article

Due to industrialization and globalization, water sources are increasingly contaminated with drugs. Among the various methods available, adsorption remains one of the most widely used techniques for drug removal. This work was to develop polysulfone (PSF) membranes integrated with montmorillonite (MMT) clay. The fabricated membranes were subsequently evaluated for their performance in removing diclofenac (DCF) from aqueous solutions. The membranes were characterized using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), contact angle measurements, as well as chemical and mechanical tests. Adding MMT at 1.5 and 2 wt% improved both hydrophilicity and mechanical strength. The natural hydrophilicity of MMT also accelerates the non-solvent/solvent exchange during phase inversion, resulting in higher porosity. These structural and surface modifications increased water permeability (16.36 L·m⁻²·h⁻¹·bar⁻¹), achieved 79% DCF removal, and enhanced antifouling properties. However, increasing the MMT clay content to 2.5 wt% caused particle aggregation, which reduced membrane performance. Fouling resistance tests with bovine serum albumin (BSA) as a model foulant showed a rejection rate of 89% and a flux recovery ratio (FRR) above 82% using an optimized membrane. These findings demonstrate that PSF/MMT membranes can serve as promising candidates for sustainable pharmaceutical wastewater treatment. Full article

Introduction. Over the past two decades, the αGal (Galα1–3Galβ1–4GlcNAc–R) epitope, a carbohydrate found in many non-primate mammals, has gained significant relevance in medicine due to its association with an increasing number of allergic reactions to animal-derived foods, drugs, and medical devices. Due to a mutated gene coding for α1,3-galactosyltransferase (α1–3GT), humans lack αGal and, therefore, naturally produce anti-α-Gal antibodies (IgM, IgA, and IgG), especially in the context of a xenotransplantation, which can lead to extreme immunological reactivity, including hyperacute rejection of the transplant. Recently, these uncontrollable immune reactions have driven demand for more accurate procedures to better detect αGal in animal-derived foods or bioprosthetics. The currently most widely used α-Gal-specific monoclonal antibody is an IgM antibody (clone M86), developed in Ggta1 KO mice and isolated from hybridoma tissue culture. As the IgM isotype has limited purification properties, specificity, and sensitivity, we aimed to produce a novel IgG antibody with high affinity and extensive applicability. Methods. An experimental murine IgG1 anti-αGal antibody (IgG-αGalomab) was developed by immunization of Ggta1 knockout (KO) mice, and its affinity was evaluated using ELISA, Western blot, flow cytometry, and immunohistochemistry/immunofluorescence. Results. Compared to IgM-M86, IgG-αGalomab demonstrated ~1200-fold higher binding potency and lower cross-reactivity with competitive molecules, i.e., bovine serum albumin, galactobiose, and lactose. Unlike IgM-M86, IgG-αGalomab showed an increasing affinity over time in the binding tests performed on xenogeneic tissues. Notably, high-affinity for αGal was detected by Western blot at high dilution [1:200,000] of IgG-αGalomab compared to IgM-M86 [1:1000]. By flow cytometry, specificity and dose-dependent response were confirmed using in vitro cultures of porcine and human fibroblasts. Finally, in immunofluorescence and immunohistochemistry analysis, αGal was demonstrated to be detectable by IgG-αGalomab at a dilution of [1:1000], while IgM-M86 was demonstrated to be detectable at [1:100]. Conclusions. Altogether, our newly developed antibody showed high sensitivity and specificity for α-Gal in various applications. Based on its potential binding capacity, IgG-αGalomab could have important applications in precision medicine for predicting, treating, and preventing immune-mediated phenomena of patients in different medical areas. Full article

Enzymatically crosslinked hydrogels are important in biomedical applications. However, conventional horseradish peroxidase (HRP)-based systems are expensive, unstable, and potentially immunogenic. Herein, we introduce hemin/albumin complexes as cost-effective and biocompatible catalysts for phenol-mediated hydrogel formation. Phenolated bovine serum albumins (BSA-LPh, -MPh, and-HPh) with different degrees of substitution were synthesized and complexed with hemin. Spectroscopic analysis demonstrated that phenol modification altered the hemin microenvironment, resulting in distinct shifts in the Soret band. Functional assays revealed that albumin complexation enhanced catalytic activity compared to hemin alone. Moderate phenol modification provided an optimal balance between catalytic efficiency and hydrogel integration, whereas excessive modification reduced the performance of the enzyme. Hydrogels containing hemin/BSA-Ph complexes exhibited controllable protein retention and high cytocompatibility (>90%) with mouse fibroblast 10T1/2 cells. These findings demonstrate that hemin/albumin complexes are promising, cost-effective, and cytocompatible alternatives to HRP systems for hydrogel-based biomedical and nonclinical applications. Full article

The non-antibacterial effects of the tetracycline antibiotic minocycline on human erythrocytes are currently under investigation. Our data indicate alterations in the surface structure of erythrocytes; the antibiotic promotes the redistribution of cellular transformational forms during preliminary in vitro incubation (1 h and 24 h) with the modifier. The degree of surface relief changes increases over time, leading to the formation of erythrocytes displaying outgrowths and ridges, spherulation, and “deflated ball”-shaped cells (after 1 day). These alterations are largely reversible, as washing the erythrocyte suspensions with a 1% bovine serum albumin solution reduces the number of echinocytes and irreversibly transformed spherocytes with spikes. Spectrophotometric analysis has shown that minocycline stabilizes the spatial organization of hemoprotein molecules, as it does not lead to increased methemoglobin formation in the samples over time. The antibiotic appears to bind primarily to amino acid residues within heme pockets, as confirmed by molecular docking. Our findings suggest a potential risk of reduced oxygen transport function in red blood cells when taking this antibiotic, highlighting the need to consider potential erythrocyte-related side effects during long-term minocycline therapy. Full article

We here present a novel and sensitive methodology for determining the melting point (MP) of Bovine Serum Albumin (BSA) from micromolar to picomolar concentration levels under label-free conditions. At 1 pM we could model the melting with a sharp Gaussian. However, from the transient state observed during the melting process by using a simple exponential decay model, we determined a time constant of 67 s. We applied this methodology by studying a 3.3 pM sample of a botulinum toxin A (BoNT-A) (stabilized with 2.8 nanomolar denatured Human Serum Albumin (HSA)). We were able to determine the Tm of BoNT-A in the presence of approximately 1000-fold more concentrated HSA. This method enables the detection of protein melting transitions at picomolar concentrations without the use of a fluorescence dye. Its sensitivity and simplicity make it a valuable analytical tool for studying protein stability in diluted pharmaceutical formulations. This method is useful for correlating thermal conformational changes with catalytic function. Full article

This study investigated the functionality and antifouling capabilities of the chitosan–silver nanoparticle–graphene oxide (CS/AgNPs/GO) composite membrane. An increase in the molecular interaction between the membrane surface and bovine serum albumin solution enhanced the flow recovery rate (FRR) due to the presence of amide -NH₂ and -OH groups. The modified CS composite showed a strong ability to prevent fouling, achieving over 77.5% due to greater interfacial intermolecular bonding. In addition, the tensile strength of the membrane composite improved from 42.7 to 49.6 MPa with an increase in the concentration of dimethylacetamide employed as a plasticizer. Therefore, efficient molecular interactions within the polymer matrix would significantly influence the membrane’s flux recovery rate, tensile strength, and ability to prevent fouling. Full article

Acute Myocardial Infarction (AMI) is a critical cardiac condition that poses a substantial threat to myocardial function. Expedient diagnosis of AMI is paramount and relies on serological assays for rapid and accurate quantification of relevant biomarkers. Electrochemical sensors have emerged as promising candidates for this application, owing to their accessibility, operational simplicity, and high specificity. In this study, we developed a paper-based electrochemical immunosensor to detect cardiac troponin I in serum and saliva specimens. The electrode was fabricated using screen-printing technology with photographic paper as the substrate, employing graphite-based ink, nail polish, and acetone as the solvent. A quasi-reference electrode was constructed using silver powder-based ink, nail polish, and acetone. The immunosensor was prepared by modifying the working electrode with gold nanoparticles (AuNP) functionalized with cardiac troponin I antibodies (anti-cTnI) and bovine serum albumin (BSA). This modified electrode was subsequently used to detect the troponin I antigen. The analyses were performed in 0.1 mol L⁻¹ phosphate buffer medium, pH 7.00, in the presence of 5.0 mmol L⁻¹ of the potassium ferrocyanide probe. The immunosensor exhibited a sensitivity of 0.006 µA/fg mL⁻¹, a limit of detection of 9.83 fg mL⁻¹, and a limit of quantification of 32.79 fg mL⁻¹. Specificity studies conducted in the presence of other macromolecules demonstrated minimal interference, with relative standard deviations (RSD) below 5.00%, indicating a specific interaction with troponin I. Furthermore, the immunosensor demonstrated excellent reproducibility and stability. Upon application to serum and saliva samples, the immunosensor presented recoveries of approximately 99–105%, suggesting its potential applicability in clinical analyses. Full article

As a favorable hydrophilic additive for antifouling modification of polyvinylidene fluoride (PVDF) membrane, titanium dioxide (TiO₂) nanoparticles have been applied for years. Sodium dodecyl sulfonate (SDS), a representative anionic surfactant, has been proven to benefit the dispersion of nano-TiO₂ via an electro-spatial stabilizing mechanism. In this study, various proportionally SDS-functionalized TiO₂ nanoparticles were adopted to modify PVDF membrane. Dispersion and stability of SDS-functionalized TiO₂ nanoparticles in casting solutions were evaluated by multiple light scattering technology. The properties and antifouling performance of PVDF/SDS-TiO₂ composite membranes were assessed. The uniformity of surface pores as well as structures on cross-section morphologies was modified. The finger-like structure of PVDF/SDS-TiO₂ composite membrane was adequately developed at the SDS/TiO₂ mass ratio of 1:1. The improved antifouling performance was corroborated by the increasing free energy of cohesion and adhesion as well as the interaction energy barrier between membrane surfaces and approaching foulants assessed by classic extended Derjaguin–Landau–Verwey–Overbeek (XDLVO) theory, the low flux decline during bovine serum albumin (BSA) solution filtration process, and the high critical flux (38 L/(m²·h·kPa)) in membrane bioreactor. This study exploits a promising way to modify PVDF membrane applicable to the wastewater treatment field. Full article

This study presents a novel ratiometric fluorescent sensor based on Förster resonance energy transfer (FRET) between glutathione (GSH)-coated CdTe quantum dots (CdTe/GSH QDs) and bovine serum albumin (BSA)-coated Au nanoclusters (AuNCs/BSA) for dopamine (DA) detection. The nanoparticles were characterized using transmission electron microscopy (TEM), zeta potential measurements, Fourier transform infrared (FTIR) spectroscopy, UV-Vis absorption and fluorescence spectroscopy. Key FRET parameters, including energy transfer efficiency (E), donor–acceptor distance (r), Förster distance (R₀), and the overlap integral (J), were determined. The interactions between the CdTe/GSH-AuNCs/BSA conjugate and DA were investigated, revealing a dual mechanism of QDs fluorescence quenching that involves both energy and electron transfer. The average lifetime values and spectral profiles of CdTe/GSH QDs, both in the absence and presence of DA, suggest a dynamic fluorescence quenching process. The variation in the ratiometric signal with increasing DA concentration demonstrated a linear response within the range of 0–250 µM, with a correlation coefficient of 0.9963 and a detection limit of 6.9 nM. This proposed nanosensor exhibited selectivity against potential interfering substances, including urea, glucose, BSA, GSH, citric acid, and metal ions such as Na⁺ and Ca²⁺. The conjugate also demonstrates excellent cytocompatibility and enhances cell proliferation in HeLa epithelial cells, making it suitable for biological applications. It was successfully employed for DA detection in urine samples, achieving recoveries ranging from 99.1% to 104.2%. The sensor is highly sensitive, selective, rapid, and cost-effective, representing a promising alternative for DA detection across various sample types. Full article

Silver sulfide quantum dots (Ag₂S QDs) are promising nanomaterials for biomedical applications due to their near-infrared emission and biocompatibility. In this study, Ag₂S QDs were synthesized using bovine serum albumin (BSA) as a stabilizing and reducing agent to assess their potential in targeted photothermal therapy. The QDs showed an average size of 1.06 ± 0.38 nm by DLS and 4.42 nm by TEM. Conjugation to an anti-PSG1 monoclonal antibody was performed via EDC/Sulfo-NHS chemistry and confirmed by FTIR spectroscopy, a decrease in zeta potential, and a redshift in emission. The conjugate exhibited an average size of 22.82 ± 9.7 nm and a zeta potential of +85.7 mV, indicating high colloidal stability. Fluorescence studies showed that the conjugate emits at 590 nm when excited at 560 nm, whereas the BSA-Ag₂S QDs (non-conjugated) emit at 480 nm upon excitation at 400 nm, reflecting changes in optical properties due to conjugation. Thermal imaging under 808 nm laser irradiation revealed efficient photothermal conversion, with temperature increases up to 13.6 °C at 200 μg/mL and a conversion efficiency of 11.41 ± 0.04%. The conjugate was non-cytotoxic to fibroblasts but induced selective cytotoxicity in HeLa cells after laser exposure, with a selectivity index of 3.0. These findings suggest that Ag₂S-BSA QDs conjugated with anti-PSG1 represent promising candidates for further investigation in cancer nanotheranostics. Full article

Determination of the multifaceted activity of selected flavone C-monoglucosides, namely orientin (OR), homoorientin (hOR), vitexin (VT), and isovitexin (iVT) in comparison to quercetin (Q) was addressed. Their antioxidant activity was characterized by the peak oxidation potentials (${\mathrm{E}}_{\mathrm{p}\mathrm{a}}$) provided by the differential pulse voltammetry (DPV) method, whereas their inhibitory activity towards angiotensin converting enzyme (ACE), acetylcholinesterase (AChE), and advanced glycation end-products (AGEs) formation was measured in a model system. The relationship between the multifaceted activity of flavone C-monoglucosides and their ${\mathrm{E}}_{\mathrm{p}\mathrm{a}}$ was evaluated. The rank of the antioxidant activity in comparison to quercetin was Q > hOR ≈ OR > iVT ≈ VT, whereas the order of the ACE inhibitory activity was Q > hOR > OR > VT > iVT. The correlation between IC₅₀ for ACE inhibition and E_pa values was r = 0.787. This finding was confirmed by the negative correlation between ACE inhibitory activity and antioxidant activity of these compounds (r = −0.838). The order of the AChE enzyme inhibitory activity was hOR > OR > iVT > VT > Q, whereas the rank of anti-AGEs activity was hOR > OR > iVT > Q > VT > AG (aminoquanidine), and the weak positive correlation between IC₅₀ and E_pa was noted (r = 0.546 for BSA (bovine serum albumin)/glucose system and r = 0.580 for BSA/methylglyoxal system). In contrast, the anti-AGEs activity was negatively correlated with IC₅₀ values for ACE inhibition (r = −0.669), whereas no correlation was found between the ACE and AChE inhibitory activities. The results expand our knowledge of the multifaceted activity of flavone C-monoglucosides. Full article

Herein, we propose an ultrasensitive electrochemical immunosensor based on glucose oxidase labeling and enzyme-catalyzed Au staining. In brief, the primary antibody (Ab₁), bovine serum albumin, an antigen and then a bionanocomposite that contains a second antibody (Ab₂), poly(3-anilineboronic acid) (PABA), Au nanoparticles (AuNPs) and glucose oxidase (GOx) are modified on a glassy carbon electrode coated with multiwalled carbon nanotubes, yielding a corresponding sandwich-type immunoelectrode. In the presence of glucose, a chemical reduction of NaAuCl₄ by enzymatically generated H₂O₂ can precipitate a lot of gold on the Ab₂-PABA-AuNPs-GOx immobilized immunoelectrode. In situ anodic stripping voltammetry (ASV) detection of gold in 8 μL 1.0 M aqueous HBr-Br₂ is conducted for the antigen assay, and the ASV detection process takes approximately 6 min. This method is employed for the assay of human immunoglobulin G (IgG) and human carbohydrate antigen 125 (CA125), which demonstrates exceptional sensitivity, high selectivity and fewer required reagents/samples. The achieved limits of detection (S/N = 3) by the method are 0.25 fg mL⁻¹ for IgG (approximately equivalent to containing 1 IgG molecule in the 1 microlitre of the analytical solution) and 0.1 nU mL⁻¹ for CA125, which outperforms many previously reported results. Full article