Search Results (19,735)

Ten substituted quinobenzothiazinium salts were tested for their ability to inhibit acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). All the compounds inhibited AChE in the IC₅₀ range of 0.03–0.658 µM, with 5,8,10-trimethyl-12H-quinolino[3,4-b][¹,⁴]benzothiazin-5-ium chloride (3d) being the most potent inhibitor, with an IC₅₀ value significantly better than that of the clinically used rivastigmine and galantamine and comparable to that of tacrine and donepezil. The IC₅₀ values for BChE inhibition ranged from 0.34 to 4.25 µM; 5,9-dimethyl-12H-quinolino[3,4-b][¹,⁴]benzothiazin-5-ium chloride (3b) exhibited the strongest BChE inhibitory activity and in general, all the investigated compounds were more potent inhibitors than rivastigmine and galantamine. Based on the calculated selectivity index values, they are rather preferential inhibitors of AChE. Cytotoxicity tests performed on normal human dermal fibroblasts (HFF-1) did not demonstrate any significant cytotoxicity under the tested conditions. The distance-oriented structure distribution for the studied molecules was related with the activity data using principal component analysis and hierarchical clustering analysis. (SAR)-based evaluation is reported to predict activity cliffs using a similarity–activity landscape index for the AChE inhibitory response values. Moreover, direct protein-mediated in silico methods were utilized to identify factors that may be relevant for quantitative (Q)SAR modeling. In practice, target-oriented molecular docking was used to organize the spatial distribution of the ligand property space for the anti-AChE system. In general, this series of alkylated quinobenzothiazinium salts with potent inhibitory activity against cholinesterases fulfills Lipinski’s rule of five based on in silico predictions and is also expected to have high absorption in the human gastrointestinal tract. All active derivatives are also expected to penetrate the blood–brain barrier, making them promising compounds for further research and possible use in Alzheimer’s disease therapy. Full article

Background: The immunologically cold nature and immunosuppressive tumor microenvironment (TME) of intrahepatic cholangiocarcinoma (ICC) contribute to its poor prognosis. This study aims to identify novel biomarkers related to prognosis and TME in ICC. Methods: We first identified the high expression of m6A reader insulin-like growth factor 2 mRNA binding protein 2 (IGF2BP2) in ICC through bioinformatics screening. Subsequently, a retrospective study was conducted on 224 ICC patients who had undergone radical resection. The expression levels of IGF2BP2 and programmed death ligand 1 (PD-L1) were detected in a tissue microarray (TMA) using immunohistochemistry (IHC). The co-localization of IGF2BP2, PD-L1, programmed cell death protein 1 (PD-1), and CD8⁺T cells was evaluated by multiple immunofluorescence techniques. Results: IHC confirmed a significant upregulation of IGF2BP2 in tumor tissues compared with normal bile duct epithelia (p < 0.05). IGF2BP2 expression was positively correlated with PD-L1 expression (TPS R = 0.215, p = 0.016; CPS R = 0.295, p = 0.008). High IGF2BP2 expression was associated with increased PD-L1/PD-1 positivity and reduced CD8⁺T cell infiltration. Kaplan–Meier analysis revealed significantly worse 3-year overall survival (OS: 20.56% vs. 29.91%, p = 0.0291) and recurrence-free survival (RFS: 9.72% vs. 18.56%, p = 0.0372) in the IGF2BP2-high group. Multivariate analysis identified IGF2BP2 as an independent risk factor for both OS (HR = 1.683, p = 0.044) and RFS (HR = 1.946, p = 0.042). Conclusions: IGF2BP2, as a potential biomarker and independent prognostic factor for ICC, is associated with increased PD-L1 expression. Full article

In recent years, yeast glucan particles (YGPs) have garnered significant attention as novel oral drug delivery carriers, owing to their superior biocompatibility, specific targeting capabilities, and intrinsic immunomodulatory properties. The yeast cell wall is primarily composed of β-glucan and mannan, with minor amounts of proteins and lipids. Among these, β-1,3-glucan serves as the pivotal functional component. It not only provides a physical barrier protecting payloads from gastric acidity and enzymatic degradation but also functions as a targeting ligand. By specifically binding to M cells in Peyer’s patches and Dectin-1 receptors on macrophages and dendritic cells, β-1,3-glucan facilitates precise drug delivery to gut-associated lymphoid tissue (GALT) or macrophage-rich inflammatory sites. Consequently, β-1,3-glucan-based YGPs demonstrate immense potential in oral targeted delivery systems for macrophage-associated pathologies. However, native YGPs, constrained by their inherent porous architecture and relatively simple physicochemical properties, often fall short of meeting the complex requirements for precise encapsulation, controlled release, and multifunctionality. To address these limitations, current research is actively exploring the functionalization of YGPs with various composite materials to engineer advanced delivery platforms. This review introduces the composition, structural characteristics, and fabrication methodologies of YGPs, alongside their specific merits and limitations in oral drug delivery. Furthermore, it critically analyzes strategies for modifying YGPs with composite materials to overcome delivery barriers. Finally, the review discusses their therapeutic applications across various diseases and outlines future developmental trends. Full article

Neurodegenerative disorders (NDs), such as Alzheimer’s and Parkinson’s diseases (AD and PD), despite having different main neuropathological hallmarks, share several interconnected aetiologic mechanisms and lack effective disease-modifying treatments. The multifactorial nature of these diseases has encouraged the development of new drugs such as multi-target-directed ligands (MTDLs). In this work, an anti-AD drug (rivastigmine, RIV) was fused and conjugated with a series of antioxidant scaffolds to obtain a small library of RIV–antiox hybrids. In addition to inhibitory activity towards both cholinesterases, these hybrids exhibited radical scavenging activity, inhibition of Aβ aggregation, and neuroprotection against cell death induced in AD models. The relevant anti-AD properties already found for these hybrids challenged us to also assess their capacity to modulate and interfere with ROS-associated harmful dysfunctions, namely in the dysregulation of biometal ions (Fe³⁺, Cu²⁺, and Zn²⁺) and upregulation of monoamine oxidases (MAOs). In particular, the capacity of the hybrids for metal chelation and inhibition of Cu-induced Aβ aggregation and MAO isoforms was evaluated, as well as their neuroprotection capacity in cell models of PD. Overall, some of these RIV hybrids appear as lead compounds for the development of novel multifunctional agents against NDs. Full article

Metal–organic frameworks (MOFs) are a versatile class of hybrid crystalline materials that have emerged as promising candidates for a broad range of applications. γ-cyclodextrin MOFs (γ-CD-MOFs) represent an innovative subgroup of MOFs constructed from “edible” γ-CD ligands coordinated with biocompatible metal ions to form an extended porous structure. Owing to their unique characteristics such as their “green” origin, biodegradability, and biocompatibility they became a promising platform for drug delivery applications. Structurally, γ-CD-MOF possess a body-centered cubic structure with dual-mode porosity, enabling the simultaneous encapsulation of hydrophilic and hydrophobic drugs. Such structural features contribute to high loading capacity, tunable release behavior, and enhanced stability of incorporated drugs. In this review, we comprehensively discuss the structural features of γ-CD-MOF, synthesis strategies, crystals size and morphology control, activation and drying techniques, and drug encapsulation approaches. We further address computational and simulation approaches used to predict and optimize drug-framework interactions, as well as post- synthetic modifications aimed at enhancing stability and functionality. The diverse pharmaceutical applications of γ-CD-MOFs are examined, including the delivery of small molecules, macromolecules, multi-drug systems, and emerging pulmonary formulations. Additionally, we examine biocompatibility and safety considerations and current limitations related to aqueous stability, industrial-scale production, and reproducibility. Finally, this review highlights recent progress and underlines future perspectives, emphasizing innovations such as fast drug-loaded MOF formation via spray-drying, co-delivery strategies, and vaccine-oriented formulations. Together, these insights highlight the potential of γ-CD-MOFs to shape the next generation of multifunctional drug delivery systems across interdisciplinary fields. Full article

Chagas disease affects millions of people worldwide, including those in Latin America. The only drugs available for its treatment are benznidazole and nifurtimox. However, these drugs present high toxicity and limited efficacy. Therefore, the search for new treatments continues. In this regard, computer-assisted drug design has been implemented in scientific research for drug repurposing, allowing for reduced costs and time. Therefore, the objective of this work was to search for analogs of FDA-approved drugs with activity against Trypanosoma cruzi through ligand-based virtual screening and their biological evaluation against blood trypomastigotes. The compound TD-095 (LC₅₀ = 48.60 and 13.75 µM), a ketanserin analogue, TS-936 (LC₅₀ = 71.55 and 37.54 µM), a terfenadine analogue, and TD-831 (LC₅₀ = 75.94 and 26.17 µM), a sulfasalazine analogue, were considered as potential trans-sialidase inhibitors; TIM-967 (LC₅₀ = 69.70 and 39.69 µM) and LK-284 (LC₅₀ = 116.7 and 82.29 µM), two sulfonylurea analogues, were considered as potential triosephosphate isomerase inhibitors, showing better trypanocidal activity against NINOA and INC-5 strains, respectively, than the reference drugs. Molecular dynamics simulations predicted the stability of the compounds in complex with their respective proteins. Finally, the ADMET predictive analysis showed favorable properties for the compounds. These results support continued research into new agents against Trypanosoma cruzi, using structures of drugs already approved by the FDA. Full article

Understanding the intrinsic Li–H₂ interaction, decoupled from substrate effects, is essential to rationalize the performance of lithium-decorated hydrogen storage materials. To address the current lack of a clean theoretical baseline, we characterized the sequential H₂ adsorption on the gas-phase Li₆ superatomic cluster using high-level density functional theory (DFT), complemented by Energy Decomposition Analysis (EDA), QTAIM, and NICS(0) calculations. Li₆ acts as a structurally rigid platform (RMSD < 0.032 Å) where ligand-induced polarization progressively strengthens its σ-aromaticity (NICS(0) from −2.917 to −13.98 ppm) and increases the HOMO–LUMO gap up to 5.05 eV. EDA identifies the binding as field-activated physisorption, electrostatically dominated (65–67%) and mechanistically distinct from Kubas coordination, as confirmed by QTAIM closed-shell interaction parameters. Negative cooperativity governs an effective loading capacity of n = 2 molecules under cryogenic conditions (T_eq = 143.76 and 114.64 K), while an entropic bottleneck renders higher loading non-spontaneous at all temperatures. These results establish Li₆(H₂)_n as a foundational gas-phase reference, providing a systematic, contamination-free descriptor set for the intrinsic Li–H₂ interaction. This framework is essential for isolating the electronic role of the lithium superatom and unambiguously identifying substrate-induced modulations in supported hydrogen storage materials. Full article

White tea infusion micro-nanoparticles (WTMPs) are important for colloidal stability, but the optimal strategy for their isolation and the mechanisms underlying their stability remain unclear. Here, a multi-indicator TOPSIS strategy was used to optimize ultrafiltration–centrifugation, and the best condition was identified as a 100 kDa membrane, 3000×g, and 20 min. The isolated WTMPs were not merely a concentrated form of white tea colloids (WTCs), but a selectively enriched fraction with remodeled composition, more regular morphology, more ordered intermolecular organization, and improved environmental stability. In particular, gallic acid (GA) was enriched, whereas caffeine (CAF) decreased markedly after isolation. Spectroscopy and molecular dynamics simulations further suggested that GA and CAF played different roles in the protein–polysaccharide network: GA was more favorable for cooperative interfacial stabilization, whereas CAF behaved more like a locally associated ligand. Overall, these results support a composition–structure–stability relationship for WTMPs and provide mechanistic insight into the selective enrichment of GA and the enhanced stability of the isolated micro-nanoparticle fraction. Full article

Background/Objectives: Precise intracellular delivery of chemotherapeutics remains a major challenge in HER2-positive breast cancer, where intratumoral heterogeneity and limited tissue penetration constrain efficacy. A key contributor is the tumor-restricted epidermal growth factor receptor variant III (EGFRvIII), a constitutively active, ligand-independent mutant generated by deletion of exons 2–7. Although classically associated with glioblastoma, lung (NSCLC), head/neck, and prostate cancers, EGFRvIII is also present in subsets of HER2-positive breast cancers, where low-abundance subclones drive aggressive phenotypes and attenuate therapeutic responses. HER2–EGFRvIII co-expression amplifies oncogenic signaling, supported by frequent co-expression in ErbB2-positive primary tumors and metastases, and by sustained receptor phosphorylation in the absence of EGFR gene amplification, depicting EGFRvIII as a compelling therapeutic target. Methods: We evaluated the shark-derived single-domain antibody vNAR R426 as a modular theranostic platform for receptor-mediated cisplatin delivery. Conjugation to cisplatin and fluorescein enabled simultaneous intracellular drug transport and immunofluorescence-based detection in EGFRvIII-positive SKBR3 cells and 3D spheroids. The compact vNAR-based immunoconjugates support efficient receptor recognition, internalization, and intracellular trafficking, features rarely achieved by conventional IgG antibodies. Results: vNAR_CDDP elicited robust, receptor-mediated cytotoxicity, achieving an IC₅₀ of 2.68 µM—approximately 50-fold lower than that of free cisplatin—while unconjugated vNAR maintained scaffold biocompatibility. In three-dimensional spheroid models, the theranostic vNAR (vNAR_CDDP+FITC) exhibited deep and uniform penetration throughout tumor-like architectures, with immunofluorescence intensity closely correlating with regions of intracellular drug delivery and the initiation of cytotoxic responses. Notably, cisplatin conjugation did not impair tissue diffusion or receptor engagement, facilitating effective payload delivery to both peripheral and central cell populations. Conclusions: By integrating tumor-restricted targeting and efficient intracellular drug delivery within a modular single-domain scaffold, vNAR R426 represents a next-generation theranostic platform capable of addressing intratumoral heterogeneity. This approach combines potent cytotoxic activity with immunofluorescence-based detection, thereby advancing the rational design of precision therapeutics for HER2-positive breast cancer. Full article

Climate change is modifying the physical structure and biogeochemical functioning of stratified marine systems, with important consequences for trace element (TE) transport, speciation, and exposure. The Black Sea provides a structurally amplified case because restricted exchange, persistent stratification, a basin-scale redoxcline, and extensive shelf-sediment reservoirs intensify climate–contaminant interactions. This review synthesizes mechanistic evidence to develop a climate-informed interpretive framework for TE redistribution under non-stationary environmental forcing. We examine how warming, deoxygenation, hydrological variability, sediment resuspension, acidification, and episodic events alter TE partitioning across dissolved, particulate, sedimentary, and biotic compartments. The synthesis identifies six major redistribution pathways involving surface-layer retention, river plume and suspended particulate transport, shelf-sediment remobilization, redoxcline dynamics, acidification–ligand effects, and event-driven exposure pulses. Together, these processes show that TE patterns increasingly reflect state-dependent internal redistribution rather than external loading alone. To address this shift, we propose a monitoring and risk-interpretation framework that links climate-sensitive state variables to redistribution pathways, integrates multiple matrices, and supports adaptive assessment through trigger-based monitoring escalation. The Black Sea is treated as a structurally amplified reference system for examining climate-sensitive redistribution pathways in stratified basins, although their expression and relative importance remain dependent on basin-specific structural controls. Full article

Di(hetero) aryl and alicyclic amine derivatives of thieno[2,3-b]pyridine were synthesized in good to high yields (45–76%) via palladium-catalyzed Buchwald–Hartwig amination. The reactions were performed using methyl 5-bromothieno[2,3-b]pyridine-2-carboxylate, prepared in this work, and a variety of substituted anilines bearing either electron-donating groups (EDGs) or electron-withdrawing groups (EWGs), as well as pyridinyl amines, and saturated heterocyclic amines such as morpholine and piperidine. For most substrates, the optimal conditions involved Pd(OAc)₂, rac-BINAP, and Cs₂CO₃ in toluene at 100 °C under argon. Substrate bearing EWGs and electron-deficient pyridinyl amines required Xantphos as the ligand, while reactions with piperidine were only successful using Pd₂(dba)₃ as a palladium (0) source. The antiparasitic activity of the synthesized compounds was evaluated against Trypanosoma brucei (T. brucei) and Leishmania infantum (L. infantum) in both promastigote and amastigote forms. Most compounds exhibited no significant cytotoxicity (CC₅₀ > 100 μM) in PMA-differentiated THP-1 derived macrophage cells. Analysis of substituent effects focusing on the nature of amino substitution at position C(5) revealed distinct trends in antiparasitic activity. Notably, one compound exhibited activity against Leishmania infantum promastigotes that was nearly four times higher than that of the reference drug miltefosine, and its selectivity index was also approximately fourfold higher. Full article

Background/Objectives: AP-2δ, encoded by TFAP2D, is one of the least characterized members of the AP-2 transcription factor family, although available evidence suggests biologically relevant roles in lung cancer that have not yet been thoroughly examined. The aim of the present study was to provide an integrated characterization of AP-2δ/TFAP2D in lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC). Methods: LUAD and LUSC data were obtained from The Cancer Genome Atlas. The analysis comprised the expression profiling of AP-2δ target genes, survival-guided TFAP2D stratification, clinical profiling, differential expression and intersection analyses, methylation-derived chromatin compartment profiling, TFAP2D-associated cofactor rewiring, and genome-wide enrichment of AP-2δ targets. In parallel, pocket prioritization was performed using an AlphaFold model of AP-2δ with cross-tool consensus mapping. Results: TFAP2D stratification delineated biologically-distinct states in both histological subtypes (LUAD and LUSC). AP-2δ target genes showed subtype-specific expression patterns and functional organization. The consistent survival association was observed for progression-free interval rather than uniformly across all endpoints. Clinical profiling was more closely associated with molecular subtype composition than broad clinicopathological differences. Differential expression analyses identified both shared and histology-dependent programs associated with TFAP2D. In the chromatin-compartment analysis, LUSC showed a broader and more coherent footprint, whereas LUAD displayed more selective cofactor rewiring. Structure-based analysis prioritized a small set of reproducible candidate pockets concentrated within ordered regions of the TF_AP-2 domain. Conclusions: AP-2δ marks biologically meaningful but histologically non-uniform regulatory states in lung cancer. These findings provide an integrated framework for understanding TFAP2D-dependent regulation in LUAD and LUSC, highlighting AP-2δ as a candidate for future mechanistic and translational investigation. Full article

Human cytomegalovirus (HCMV) remains a significant cause of morbidity in immunocompromised patients, necessitating the development of improved antivirals. Using an integrated in silico and in vitro approach, we identified a novel ligand (NL) as a letermovir analog with enhanced binding affinity and reduced cytotoxicity. A pUL56 terminase subunit model generated with AlphaFold 3 was used for the virtual screening of a 15,000-compound library. Among the 73 candidates with structural similarity to letermovir (Tanimoto ≥ 0.6), NL exhibited superior predicted binding affinity (ΔG_bind = −10.7 kcal/mol). In silico toxicity prediction (ProTox 3.0) classified NL as having low toxicity (class 4, LD50 ≈ 1000 mg/kg), which was confirmed in vitro, where NL demonstrated 158-fold less toxic (CC50 = 2.69 mg/mL) in MRC-5 cells than letermovir (0.017 mg/mL). Molecular dynamics simulations over 500 ns revealed that the pUL56-NL complex forms a more thermodynamically stable interaction, with a lower calculated free energy of binding (MMGBSA: −40.89 ± 7.40 kcal/mol vs. −32.76 ± 4.96 kcal/mol) and a narrower free energy landscape. These results establish NL as a promising, low-cytotoxicity candidate with enhanced target engagement, warranting further investigation as a potential anti-HCMV therapeutic. Full article

Osteoclast hyperactivity represents a central mechanism in pathological bone destruction, underscoring the importance of discovering novel anti-resorptive compounds. In this study, we present early-stage evidence that 8-Epixanthatin can inhibit osteoclast differentiation induced by receptor activator of nuclear factor kappa-B ligand (RANKL). 8-Epixanthatin exhibited no significant cytotoxicity at the concentrations used for osteoclast differentiation studies. The compound showed concentration-dependent reductions in TRAP-positive multinucleated osteoclasts, with an IC₅₀ value of 2.3 μM. Our mechanistic investigations revealed that 8-Epixanthatin interferes with RANKL-activated signaling networks, particularly nuclear factor kappa-B (NF-κB) and mitogen-activated protein kinase (MAPK) cascades. Collectively, these observations identify 8-Epixanthatin as a promising lead structure for anti-osteoclast drug discovery. Full article

Glycosylation is one of the most prevalent post-translational modifications of membrane proteins and plays a central role in regulating their structure and function. Unlike many existing reviews that address glycosylation in a system-wide context, this review focuses specifically on membrane proteins and examines how glycosylation shapes their functional behavior and clinical relevance. Because membrane proteins are exposed to the extracellular environment, glycans on their surface directly influence protein folding, receptor organization, and interactions with ligands and immune components. These diverse effects can be understood within a common mechanistic framework in which glycosylation modulates protein conformation, receptor clustering, and membrane organization, thereby altering signaling, adhesion, transport, and immune recognition. We discuss how N-linked and O-linked glycosylation regulate major classes of membrane proteins across these processes. Particular attention is given to disease-associated alterations in glycosylation, especially in cancer, immune and inflammatory disorders, and metabolic disease. For instance, glycosylation-dependent stabilization of PD-L1 and modulation of receptor signaling, such as EGFR, illustrate how glycan modifications contribute to immune evasion and therapeutic response. We further consider the clinical implications of membrane protein glycosylation, including its roles in biomarker development and as a potential target for therapeutic intervention. Advances in glycoproteomic technologies have enabled increasingly detailed characterization of site-specific glycosylation, although significant analytical challenges remain, particularly for membrane proteins. Overall, this review highlights membrane protein glycosylation as a dynamic regulatory layer that links molecular mechanisms to functional outcomes and clinical applications. Full article