Search Results (666)

This study systematically explored the interaction mechanisms between two KRAS G12C inhibitors (Sotorasib and Adagrasib) and human serum albumin (HSA) via UV-vis spectroscopy, fluorescence spectroscopy, three-dimensional fluorescence spectroscopy, and molecular docking methods. The experimental findings demonstrated that both drugs caused static quenching of HSA fluorescence, with binding constants of 13.64 × 10³ M⁻¹ (Sotorasib) and 63.67 × 10³ M⁻¹ (Adagrasib), demonstrating significant selectivity differences in their binding affinities. UV spectral analysis demonstrated distinct microenvironmental perturbations: Sotorasib and Adagrasib induced a shift (∆λ = 7 nm and ∆λ = 8 nm, respectively) at 211 nm, consistent with altered polarity in HSA’s binding pockets. Fluorescence spectroscopy confirmed a 1:1 binding stoichiometry, with Stern-Volmer analysis validating static quenching as the dominant mechanism. Three-dimensional fluorescence spectra further highlighted Adagrasib’s stronger conformational impact, reducing tyrosine and tryptophan residue fluorescence intensities by 16% (Peak 1) and 10% (Peak 2), respectively, compared to Sotorasib. Molecular docking revealed divergent binding modes: Sotorasib occupied Sudlow Site I via three hydrogen bonds and hydrophobic interactions (∆G = −24.60 kJ·mol⁻¹), whereas Adagrasib bound through one hydrogen bond and hydrophobic forces (∆G = −30.92 kJ·mol⁻¹), with stability differences attributed to structural characteristics. This study uses multispectral technology and molecular docking to reveal the binding mechanism of Sotorasib and Adagrasib with HSA, providing a theoretical basis for designing highly targeted albumin nanocarriers. The strong binding properties of Adagrasib and HSA may reduce the toxicity of free drugs, providing direction for the development of long-acting formulations. Full article

Background: Anaplastic lymphoma kinase (ALK) is a key receptor tyrosine kinase involved in regulating signaling pathways critical for cell proliferation, differentiation, and survival. Mutations or rearrangements of the ALK gene lead to aberrant kinase activation, driving tumorigenesis in various cancers. Although ALK inhibitors have shown clinical benefits, drug resistance remains a significant barrier to long-term efficacy. Developing novel ALK inhibitors capable of overcoming resistance is therefore essential. Methods: A structure-based pharmacophore model was constructed using the 3D structures of five approved ALK inhibitors. Systematic virtual screening of the Topscience drug-like database was performed incorporating PAINS filtering, ADMET prediction, and molecular docking to identify promising candidates. In vitro antiproliferative assays, molecular docking, molecular dynamics simulations, and MM/GBSA binding free energy calculations were used to evaluate biological activity and elucidate binding mechanisms. Results: Two candidates, F1739-0081 and F2571-0016, were identified. F1739-0081 exhibited moderate antiproliferative activity against the A549 cell line, suggesting potential for further optimization. Computational analyses revealed its probable binding modes and interactions with ALK, supporting the observed activity. Conclusions: This study successfully identified novel ALK inhibitor candidates with promising biological activity. The integrated computational and experimental approach provides valuable insights for the rational design of optimized ALK inhibitors to address drug resistance in cancer therapy. Full article

Background: Hepatocellular carcinoma is one of the leading causes of cancer-related deaths worldwide. Its high recurrence rate and limited treatment options underscore the urgent need for the development of new and highly effective drugs. Methods: This study systematically explores the molecular mechanism of cinnamic acid against hepatocellular carcinoma through integrated machine learning prediction, network pharmacological analysis and in vitro experimental verification. Results: The prediction of anti-tumor activity based on the random forest model showed that cinnamic acid has significant anti-tumor potential (probability = 0.69). Network pharmacology screened 185 intersection targets of cinnamic acid and liver cancer, of which 39 core targets (such as PIK3R1, AKT1, MAPK1) were identified as key regulatory hubs through protein interaction network and topological analysis. Functional enrichment analysis showed that these targets were mainly enriched in the PI3K/AKT signaling pathway (p = 2.1 × 10⁻¹²), the cancer pathway (p = 3.8 × 10⁻¹⁰), and apoptosis-related biological processes. Molecular docking validation revealed that the binding energies of cinnamic acid with the 19 core targets were all below −5 kcal/mol, a threshold indicating strong binding affinity in molecular docking. The binding modes to PIK3R1 (−5.4 kcal/mol) and AKT1 (−5.1 kcal/mol) stabilized through hydrogen bonding. In vitro, cinnamic acid dose-dependently inhibited Hep3B proliferation/migration, induced apoptosis, downregulated PI3K, p-AKT, and Bcl-2, and upregulated Bax and Caspase-3/8. Conclusions: This study systematically reveals, for the first time, that the multi-target mechanism of cinnamic acid exerts anti-hepatic cancer effects by targeting the PI3K/AKT signaling pathway, supporting its potential as a natural anti-tumor drug. Full article

We present a dual biosensing strategy integrating Quartz Crystal Microbalance (QCM) and Surface-Enhanced Raman Spectroscopy (SERS) for the quantitative and molecular-specific detection of FKBP12. Silver nanodendritic arrays were electrodeposited onto QCM sensors, optimized for SERS enhancement using Rhodamine 6G, and functionalized with a custom-designed receptor to selectively capture FKBP12. QCM measurements revealed a two-step Langmuir adsorption behavior, enabling sensitive mass quantification with a low limit of detection. Concurrently, in situ SERS analysis on the same sensor provided vibrational fingerprints of FKBP12, resolved through comparative studies of the free protein, surface-bound receptor, and surface-bound receptor–protein complex. Ethanol-induced denaturation confirmed protein-specific peaks, while shifts in receptor vibrational modes—linked to FKBP12 binding—demonstrated dynamic molecular interactions. A ratiometric parameter, derived from key peak intensities, served as a robust, concentration-dependent signature of complex formation. This platform bridges quantitative (QCM) and structural (SERS) biosensing, offering real-time mass tracking and conformational insights. The nanodendritic substrate’s dual functionality, combined with the receptor’s selectivity, advances label-free protein detection for applications in drug diagnostics, with potential adaptability to other target analytes. Full article

Objective: The development of natural and new P-gp modulators to reverse tumor multidrug resistance (MDR). Methods: Test compounds were prepared from the plant Metaplexis japonica, and their ability to reverse P-glycoprotein (P-gp)-mediated MDR was investigated in HepG2/Dox cells. Their effects on P-gp expression and function and their interaction modes with P-gp were also investigated. Results: Natural product 3β,12β,14β, 17β,20(S)-pentahydroxy-5α-pregnan-12β-O-(E)-cinnamate (1) and its new semisynthetic derivative 3β12β,14β,17β,20(S)-pentahydroxy-5α-pregnan-3β-O-nicotinate-12β-O-(E)-cinnamate (1a) were obtained. At non-cytotoxic concentrations of 5 or 10 μM, they significantly reversed the resistance of HepG2/Dox cells to P-gp substrate drugs doxorubicin, paclitaxel, and vinblastine, with reversal folds of 7.1, 118.5, and 198.3 (1), and 18.8, 335.8, and 140.0 (1a), respectively, at 10 μM. Cell apoptosis and expression of caspase 9 were both triggered by the combination of 10 μM of compound 1 or 1a and 500 nM of paclitaxel (p < 0.001). Compound 1 or 1a did not affect P-gp expression, but it did significantly suppress the efflux of Rhodamine 123 out of HepG2/Dox cells (p < 0.001). On the Caco-2 cell monolayer, 1 and 1a were shown to be non-substrates of P-gp, with efflux ratios of 0.83 and 0.89. Molecular docking revealed their strong binding energies (−8.2 and −8.4 kcal/mol) with P-gp, and their direct binding to P-gp was confirmed by their dissociation constants (5.53 µM for 1 and 3.72 µM for 1a), determined using surface plasmon resonance. Conclusions: Compounds 1 and 1a are potential P-gp modulators; they may reverse P-gp-MDR through interacting with P-gp to interfere with substrate binding and transporting, and have the potential to improve the efficacy of paclitaxel or vinblastine drugs for combating P-gp-mediated MDR in tumor cells. Full article

Background: Antibacterial resistance (ABR) poses a major challenge to global health, with methicillin-resistant Staphylococcus aureus (MRSA) being one of the prominent multidrug-resistant strains. MRSA has developed resistance through the expression of Penicillin-Binding Protein 2a (PBP2a), a key transpeptidase enzyme involved in bacterial cell wall biosynthesis. Objectives: The objective was to design and characterize a novel small-molecule inhibitor targeting PBP2a as a strategy to combat MRSA. Methods: We synthesized a new indole triazole conjugate (ITC) using eco-friendly and click chemistry approaches. In vitro antibacterial tests were performed against a panel of strains to evaluate the ITC antibacterial potential. Further, a series of in silico evaluations like molecular docking, MD simulations, free energy landscape (FEL), and principal component analysis (PCA) using the crystal structure of PBP2a (PDB ID: 4CJN), in order to predict the mechanism of action, binding mode, structural stability, and energetic profile of the 4CJN-ITC complex. Results: The compound ITC exhibited noteworthy antibacterial activity, which effectively inhibited the selected strains. Binding score and energy calculations demonstrated high affinity of ITC for the allosteric site of PBP2a and significant interactions responsible for complex stability during MD simulations. Further, FEL and PCA provided insights into the conformational behavior of ITC. These results gave the structural clues for the inhibitory action of ITC on the PBP2a. Conclusions: The integrated in vitro and in silico studies corroborate the potential of ITC as a promising developmental lead targeting PBP2a in MRSA. This study demonstrates the potential usage of rational drug design approaches in addressing therapeutic needs related to ABR. Full article

Leishmaniasis is an infectious disease common in tropical and subtropical regions worldwide. This study aimed to develop a topical meglumine antimoniate gel (MA-gel) for the treatment of cutaneous leishmaniasis. The MA-gel was characterized in terms of morphology, pH, swelling, porosity, rheology, and thermal properties by differential scanning calorimetry (DSC). Biopharmaceutical evaluation included in vitro drug release and ex vivo skin permeation. Safety was evaluated through biomechanical skin property measurements and cytotoxicity in HaCaT and RAW 267 cells. Leishmanicidal activity was tested against promastigotes and amastigotes of Leishmania infantum, and in silico studies were conducted to explore possible mechanisms of action. The composition of the MA-gel included 30% MA, 20% Pluronic^® F127 (P407), and 50% water. Scanning electron microscopy revealed a sponge-like and porous internal structure of the MA-gel. This formula exhibited a pH of 5.45, swelling at approximately 12 min, and a porosity of 85.07%. The DSC showed that there was no incompatibility between MA and P407. Drug release followed a first-order kinetic profile, with 22.11 µg/g/cm² of the drug retained in the skin and no permeation into the receptor compartment. The MA-gel showed no microbial growth, no cytotoxicity in keratinocytes, and no skin damage. The IC₅₀ for promastigotes and amastigotes of L. infantum were 3.56 and 23.11 µg/mL, respectively. In silico studies suggested that MA could act on three potential therapeutic targets according to its binding mode. The MA-gel demonstrated promising physicochemical, safety, and antiparasitic properties, supporting its potential as a topical treatment for cutaneous leishmaniasis. Full article

The glucagon-like peptide-1 receptor (GLP-1R), which belongs to the class B1 G protein-coupled receptor (GPCR) family, is an important target for treatment of metabolic disorders, including type 2 diabetes and obesity. The growing interest in GLP-1R-based therapies is driven by the development of various functional agonists as well as the huge commercial market. Thus, understanding the structural details of ligand-induced signaling are important for developing improved GLP-1R drugs. Here, we investigated the conformational dynamics of the receptor in complex with a selection of prototypical functional agonists, including CHU-128 (small molecule-biased), danuglipron (small molecule balanced), and Peptide 19 (peptide balanced), which exhibit unique, distinct binding modes and induced helix packing. Furthermore, our all-atom molecular dynamics (MD) simulations revealed atomic feature how different those ligands led to signaling pathway preference. Our findings offer valuable insights into the mechanistic principle of GLP-1R activation, which are helpful for the rational design of next-generation GLP-1R drug molecules. Full article

Transthyretin amyloidosis (ATTR) is a disease caused by the deposition of transthyretin-derived fibrils in the body. Despite extensive research conducted over the years, there are currently only four drugs available in clinical use to treat this condition, two of which are repurposed drugs used off-label. However, these treatments present several limitations; therefore, there is an urgent need for new therapeutic options. In this context, dietary supplements containing natural compounds capable of stabilizing the transthyretin (TTR) protein could represent a promising approach to contrast the disease progression, potentially supporting the therapeutic effects of the aforementioned drugs. In light of this, the present review highlights and analyzes the natural compounds that have most recently been reported in the literature as TTR stabilizers. In particular, the studies elucidating the potential of these compounds in the treatment of ATTR, along with the available crystallographic data explaining their binding mode to TTR, are reported. Overall, although the use of natural compounds as supplements shows promise in managing ATTR, further research is still needed to explore its feasibility and confirm its effectiveness. Hopefully, this work will help shed light on these issues and serve as a useful starting point for the development of new strategies to treat this disease. Full article

Eukaryotic elongation factor 1A (eEF1A), the second most abundant intracellular protein, not only plays a key role in peptide elongation, but is also capable of numerous moonlighting functions. Within malignant cells, eEF1A is by no means a neutral bystander but instead actively participates in oncogenic transformations via a myriad of molecular pathways. Thus far, a broad range of small-molecule inhibitors have been identified, which, despite their structural diversity, suppress tumor growth by targeting eEF1A. Interestingly, just as eEF1A enables its oncogenic potential far beyond boosting protein translation, these targeted agents disrupt this oncoprotein via multiple axes distinct from mere protein synthesis inhibition. Whereas the oncogenic mechanisms of eEF1A has been well documented, there lacks a systemic survey of the eEF1A-targeting agents in terms of their mechanisms. Accordingly, the present work aims to examine their multifaceted modes of action more than just blocking protein synthesis. By unveiling these insights, our deepened knowledge of these eEF1A-binding inhibitors will inform the development of future eEF1A-targeted drugs for cancer treatment. Full article

Oximes have been reported to exhibit useful pharmaceutical properties, including compounds with anticancer, anti-arthritis, antibacterial, and neuroprotective activities. Many oximes are kinase inhibitors and have been shown to inhibit various kinases. Herein, a panel of oxime derivatives of tricyclic isatins was synthesized and evaluated for inhibition of cellular inflammatory responses and binding affinity to several kinases. Compounds 5a and 5d (a.k.a. NS-102), which have an unsubstituted oxime group, inhibited lipopolysaccharide (LPS)-induced nuclear factor-κB/activating protein 1 (NF-κB/AP-1) transcriptional activity in human THP-1Blue monocytic cells and interleukin-6 (IL-6) production in human MonoMac-6 monocytic cells, with IC₅₀ values in the micromolar range. These compounds also inhibited LPS-induced production of several other proinflammatory cytokines, including IL-1α, IL-1β, monocyte chemoattractant protein-1 (MCP-1), and tumor necrosis factor (TNF) in MonoMac-6 cells. Compounds 5a and 5d exhibited nanomolar/submicromolar binding affinity toward several kinase targets. The most potent inhibitor, 5d (3-(hydroxyimino)-5-nitro-1,3,6,7,8,9-hexahydro-2H-benzo[g]indol-2-one), demonstrated high binding affinity for 12 kinases, including DYRK1A, DYRK1B, PIM1, Haspin, HIPK1-3, IRAK1, NEK10, and DAPK1-3. Molecular modeling suggested modes of binding interaction of selected compounds in the DYRK1A and PIM1 catalytic sites that agreed with the experimental binding data. Our results demonstrate that tricyclic isatin oximes could be potential candidates for developing anti-inflammatory drugs with neuroprotective effects for treating neurodegenerative diseases. Full article

This study aimed to design dual-responsive chitosan–polylactic acid nanosystems (PLA@CS NPs) for controlled and targeted ledipasvir (LED) delivery to HepG2 liver cancer cells, thereby reducing the systemic toxicity and improving the therapeutic selectivity. Two formulations were developed utilizing ionotropic gelation and w/o/w emulsion techniques: LED@CS NPs with a size of 143 nm, a zeta potential of +43.5 mV, and a loading capacity of 44.1%, and LED-PLA@CS NPs measuring 394 nm, with a zeta potential of +33.3 mV and a loading capacity of 89.3%, with the latter demonstrating significant drug payload capacity. Since most drugs work through interaction with DNA, the in vitro affinity of DNA to LED and its encapsulated forms was assessed using stopped-flow and other approaches. They bind through multi-modal electrostatic and intercalative modes via two reversible processes: a fast complexation followed by a slow isomerization. The overall binding activation parameters for LED (cordination affinity, K_a = 128.4 M⁻¹, K_d = 7.8 × 10⁻³ M, ΔG = −12.02 kJ mol⁻¹), LED@CS NPs (K_a = 2131 M⁻¹, K_d = 0.47 × 10⁻³ M, ΔG = −18.98 kJ mol⁻¹) and LED-PLA@CS NPs (K_a = 22026 M⁻¹, K_d = 0.045 × 10⁻³ M, ΔG = −24.79 kJ mol⁻¹) were obtained with a reactivity ratio of 1/16/170 (LED/LED@CS NPs/LED-PLA@CS NPs). This indicates that encapsulation enhanced the interaction between the DNA and the LED-loaded nanoparticle systems, without changing the mechanism, and formed thermodynamically stable complexes. The drug release kinetics were assessed under tumor-mimetic conditions (pH 5.5, 10 mM GSH) and physiological settings (pH 7.4, 2 μM GSH). The LED@CS NPs and LED-PLA@CS NPs exhibited drug release rates of 88.0% and 73%, respectively, under dual stimuli over 50 h, exceeding the release rates observed under physiological conditions, which were 58% and 54%, thereby indicating that the LED@CS NPs and LED-PLA@CS NPs systems specifically target malignant tissue. Release regulated by Fickian diffusion facilitates tumor-specific payload delivery. Although encapsulation did not enhance the immediate cytotoxicity compared to free LED, as demonstrated by an in vitro cytotoxicity in HepG2 cancer cell lines, it significantly enhanced the therapeutic index (2.1-fold for LED-PLA@CS NPs) by protecting non-cancerous cells. Additionally, the nanoparticles demonstrated broad-spectrum antibacterial effects, suggesting efficacy in the prevention of chemotherapy-related infections. The dual-responsive LED-PLA@CS NPs allowed controlled tumor-targeted LED delivery with better selectivity and lower off-target toxicity, making LED-PLA@CS NPs interesting candidates for repurposing HCV treatments into safer cancer nanomedicines. Furthermore, this thorough analysis offers useful reference information for comprehending the interaction between drugs and DNA. Full article

This study presents a detailed Raman spectroscopic investigation of hydrogels composed of sodium hyaluronate and two N-terminally blocked dipeptides: N-acetyl-L-alanine-methyl-amide (NAcAlaNHMA) and N-acetyl-L-tyrosine-methyl-amide (NAcTyrNHMA). Vibrational spectra of the dipeptides in both crystalline and aqueous forms were analyzed and supported by density functional theory (DFT) calculations. Spectral features of the hyaluronan component were elucidated by simulating the vibrational modes of its two principal disaccharide building blocks. Gels were prepared with varying dipeptide-to-hyaluronan ratios, and their structural characteristics were examined using Raman spectroscopy and atomic force microscopy. The results showed that while NAcAlaNHMA exhibited no significant interaction with the HA matrix, NAcTyrNHMA demonstrated specific binding behavior, as evidenced by notable shifts in its N–H and C–O–H vibrational bands. These findings indicate that NAcTyrNHMA binds to hyaluronic acid via hydrogen bonding, likely involving carboxyl and hydroxyl functional groups. This study highlights the potential for selective tuning of HA-based hydrogels using dipeptides, with implications for biomedical applications such as drug delivery, antimicrobial gels and biomaterial design. Full article

Multidrug resistance (MDR) poses a significant challenge in cancer therapy, often leading to treatment failure and relapse. ATP-binding cassette (ABC) transporters, particularly ABCG2, play a pivotal role in MDR development by actively expelling chemotherapeutic agents from cancer cells. This study investigates the effects of two groups of primaquine derivatives—fumardiamides (1a–d) and bis-ureas (2a, b), both bearing halogenated benzene rings—on the activity of P-glycoprotein (P-gp) and ABCG2. Their potential to reverse MDR was evaluated through a series of functional assays aimed at comparing transporter–compound interactions. The results indicated that fumardiamide derivatives, specifically 1a, 1b, and 1d, exhibited potent inhibition of ABCG2 while having no effect on P-gp, demonstrating a selective mode of action. The tested derivatives displayed low to moderate cytotoxicity and did not affect ABCG2 expression or localization. Moreover, these compounds enhanced the sensitivity of drug-resistant cancer cell lines to mitoxantrone, underscoring their potential to overcome ABCG2-mediated MDR. These findings suggest that chemical modifications of primaquine, particularly the incorporation of fumardiamide moieties, confer novel biological properties, providing promising leads for the development of selective ABCG2 inhibitors. Full article

The growing demand for therapeutic monoclonal antibodies (mAbs) has heightened the need for efficient and scalable purification strategies. A major challenge in downstream processing is the removal of antibody aggregates, which can compromise drug safety, efficacy, and regulatory compliance. This review explores the use of multimodal chromatography for aggregate separation, providing an in-depth analysis of commercially available resins and emerging adsorbent prototypes. It also examines the mechanisms of aggregate formation during bioprocessing. A comparative evaluation of conventional single-mode chromatography techniques—affinity, ion exchange, and hydrophobic interaction—is presented alongside multimodal chromatography, which integrates ion-exchange, hydrophobic, and other non-covalent interactions for enhanced aggregate clearance and process flexibility. The review primarily assesses commercial multimodal resins in terms of aggregate removal efficiency, binding capacity, and scalability. Additionally, advancements in prototype resins and multimodal membranes are discussed. Finally, the advantages, limitations, and future directions of multimodal chromatography in mAb aggregate removal are outlined. As purification demands continue to evolve, multimodal chromatography is poised to play an increasingly critical role in achieving the high purity standards required for therapeutic antibodies. Full article