Search Results (225)

Ruthenocene (Rc) and its derivatives form a structurally versatile class of metallocenes with unique and multifunctional applicability. This review presents a detailed analysis of Rc chemistry including the structural comparison with ferrocene, its redox behavior, and substituent effects. We also discuss its applications in sensing, energy storage, photochemistry, and biomedicine. Rc exhibits unique conformational and adaptive electronic properties based on one and two-electron oxidation processes. Electrochemical investigations of Rc to date indicate that its redox behavior is strongly dependent on the electrolyte system, exhibiting quasi-Nernstian characteristics, the formation of stabilized dimeric species [Rc₂]²⁺, and interconversion among Ru(II), Ru(III), and Ru(IV) oxidation states. Rc-based systems exhibit superior performance as redox mediators and labels in electrochemical sensing systems in terms of electron-transfer kinetics, signal amplification, and surface immobilization. In the field of energy storage, Rc decreases the charging overpotential and increases the cycle life of Li-O₂ batteries. Rc further acts as a photoinitiator via charge-transfer-to-solvent and efficient photoinduced electron transfer in metalloporphyrin and fullerene dyads. In biomedical research, Rc derivatives as well as bioconjugates possess promising anticancer activities, displaying reactive oxygen species generation, topoisomerase inhibition, thioredoxin reductase inhibition, receptor-mediated uptake, and target peptide conjugation. Given its flexible ligand design, electrolyte driven redox behaviors, and antiproliferative properties, Rc exhibits a very adaptive molecular scaffold for next generation electrochemical technologies as well as metallodrug design. Full article

Glucagon-like peptide-1 (GLP-1) is an incretin hormone secreted by intestinal endocrine L cells that activates the GLP-1 receptor (GLP-1R), leading to glucose-dependent insulin secretion and suppression of glucagon release. In recent years, GLP-1R agonists (GLP-1RAs) have become one of the leading therapeutic options for the treatment of type 2 diabetes mellitus; however, for a long time clinically approved GLP-1RAs were limited to peptide drugs unsuitable for oral administration. The discovery of the “first-in-class” small molecule agonist danuglipron in 2018 demonstrated the feasibility of orally available GLP-1RAs and stimulated the development of numerous danuglipron-like compounds, some of which showed increased efficacy over the prototype. In this study, we report the design and synthesis of novel GLP-1RAs based on a regioisomeric danuglipron scaffold, 1H-benzo[d]imidazole-5-carboxylic acid. A series of 35 compounds was synthesized and evaluated in vitro for cytotoxicity and GLP-1R agonistic activity using a cAMP accumulation assay. A potent lead compound 12r (pEC₅₀ = 7.72, pCC₅₀ < 3.60) was found which is a close structural analog of danuglipron with reduced cytotoxicity and excellent selectivity over two other class B GPCRs, including GCGR and GIPR. Despite decreased potency compared to danuglipron, the obtained results hold promise for further optimization and provide valuable structure–activity relationship insights. Full article

The optimization of membrane permeability is a pivotal approach for mitigating late-stage failures in peptide drug development. By leveraging linker chemical diversity, stapled peptides utilize linker engineering to precisely modulate key physicochemical parameters—such as lipophilicity and conformational constraints—to overcome the desolvation energy penalty. This review systematically evaluates linker-based strategies for enhancing the permeability of stapled peptides, categorized into two primary dimensions: (1) high-throughput screening (HTS) compatibility, focusing on the integration of functionalized linkers into mRNA display, phage display, and DNA-encoded libraries (DELs) to identify lead scaffolds with inherent permeability potential during early discovery; and (2) post-screening structural refinement, covering rational design strategies including intramolecular hydrogen-bond (IMHB) shielding, “chameleonic” adaptations, and stimuli-responsive reversible stapling. Furthermore, we analyze the paradigm shift in assessment methodologies from qualitative imaging to quantitative cytosolic delivery assays, which have deepened our understanding of mechanisms such as the charge/lipophilicity threshold balance and metabolism-driven trapping. Overall, linker engineering provides a robust technical roadmap for developing the next generation of cell-permeable stapled peptide therapeutics. Full article

Herpes simplex virus type 1 (HSV-1) is a neurotropic alphaherpesvirus that interacts dynamically with host cells within structured tissue environments. Conventional two-dimensional (2D) cultures do not fully recapitulate these spatial and microenvironmental features. In this study, we established a three-dimensional (3D) culture system using the self-assembling peptide RADA16-I to generate an extracellular matrix–mimetic hydrogel scaffold. This platform supported the formation of stable Vero cell spheroids that remained viable for more than 30 days. Following HSV-1 infection, viral spread initiated at the spheroid periphery and progressively extended toward the core. Sustained viral replication was detected for up to 22 days, indicating long-term maintenance of infection within the 3D structure. Ultrastructural examination identified viral particles and vesicular compartments consistent with autophagy-related organelles. Comparative analysis of autophagy-associated markers revealed distinct temporal patterns between 2D monolayer cultures and 3D spheroids. In the 3D system, LC3B-II levels progressively increased, accompanied by a reduction in p62, suggesting altered regulation of autophagic flux relative to conventional 2D conditions. These findings demonstrate that the RADA16-I-based 3D culture model supports prolonged HSV-1 infection and reproduces key spatial features of viral dissemination. The differential autophagic responses observed between 2D and 3D systems highlight the influence of cellular architecture on host–virus interactions and support the application of 3D culture platforms for mechanistic studies of HSV-1 pathogenesis. Full article

Once-monthly injectable therapies targeting glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), and adjacent metabolic pathways are moving from a conceptual goal to a plausible next step for type 2 diabetes (T2D) and obesity. The most clinically advanced program is maridebart cafraglutide (MariTide), a long-acting GLP-1 receptor agonist conjugated to an Fc-containing scaffold that also mediates sustained GIP receptor antagonism. Across phase 2 trials, once-monthly maridebart has produced clinically meaningful weight loss (~12–16% in adults without diabetes; ~8–12% in those with T2D), together with HbA1c reductions of ~1.2–1.6 percentage points, with a safety profile broadly consistent with GLP-1-based therapy. An exploratory every-8-weeks regimen showed attenuated efficacy, suggesting that monthly dosing may represent a practical lower boundary for maintaining therapeutic exposure and metabolic effect in this format. Beyond maridebart, a rapidly expanding pipeline—including ultra-long-acting GLP-1 analogs, dual GLP-1/GIP agonists, long-acting GIPR antagonists, amylin receptor agonists, and emerging thyroid hormone receptor beta (THRβ) agonists—is actively testing monthly regimens or induction-to-monthly maintenance strategies; however, most readouts remain early and are frequently limited to conference presentations or sponsor communications. Accordingly, much of the pipeline evidence should be interpreted as early-phase and non-peer-reviewed, and therefore hypothesis-generating. Key uncertainties include long-term durability, cardiometabolic outcomes, immunogenicity, and interindividual variability in response, which will ultimately determine how once-monthly regimens integrate with established weekly standards in routine care. Full article

Head and neck squamous cell carcinomas (HNSCCs) are considered the most common histological type of head and neck cancer. This study aims to develop a drug delivery system based on zein protein nanoparticles (Zein NPs) to enhance the therapeutic effect of the anticancer peptide, Pistacia zardin1 (PZ1), for the treatment of maxillofacial cancers. PZ1-Zein NPs were synthesized by the desolvation method. These spherical nanoparticles (size: 162.8 nm, PDI: 0.27) showed high encapsulation efficiency (89%) and pH-responsive release (with higher drug release in the acidic tumor microenvironment). In vitro cytotoxicity assays showed that PZ1-Zein NPs significantly reduced IC50 values in HNSCC cell lines (e.g., SCC-25: 7.5 µM vs. 19.3 µM for free peptide, p < 0.001) while exhibiting improved selectivity for cancer cells over normal HaCaT cells. Mechanistic investigations confirmed that PZ1-Zein NPs significantly increased apoptosis, as shown by increased caspase-3/7 activity (5.8-fold vs. 2.6-fold). These findings highlight PZ1-Zein NPs as a promising nanomedicine strategy and a candidate functional component for future dual-functional scaffolds aimed at targeted hard tissue engineering and surgery in HNSCC management. Full article

Background/Objectives: Nature has evolved millions of venom-derived peptides with diverse biological functions, a substantial fraction of which target complex membrane proteins such as G-protein-coupled receptors and ion channels. Many of these peptides are stabilized by multiple disulfide bonds, endowing them with exceptional structural stability and favorable pharmacological properties. Methods: Leveraging this natural diversity, we developed a robust venom peptide therapeutics discovery system built on phage display technology and constructed a library using approximately 482 venom-derived scaffolds. The library design was guided by a machine learning (ML) model capable of predicting mutation-tolerant residues that preserve peptide foldability, maximizing structural integrity and sequence diversity. Results: The resulting VCX library was evaluated through screening against four diverse targets (CD47, DLL3, IL33, and P2X7R), yielding strong binders for all four, a success rate of 100%. Furthermore, by integrating high-throughput recombinant expression of thioredoxin–venom fusion proteins along with ML-assisted affinity maturation, we rapidly identified potential leads for DLL3 binders. Conclusions: This venom-based discovery platform offers significant advantages in both functionality and developability compared with conventional peptide discovery approaches. By combining natural structural diversity, ML-guided design, and recombinant expression, it enables efficient identification of “antibody-like” binders with molecular weights much smaller than those of antibodies. Consequently, it provides a powerful strategy for developing next-generation peptide therapeutics targeting challenging protein–protein interactions and complex membrane proteins. Full article

The scorpion family Buthidae, renowned for its neurotoxin-rich venoms, dominates toxinology, while non-buthid venoms remain largely unexplored. Here, we present a comprehensive proteomic and biochemical characterization of the Amazonian chactid scorpion Brotheas amazonicus venom (BamazV), with emphasis on molecular complexity, proteolytic processing, and peptide diversity. Using an integrative venomics approach that combines molecular mass-based fractionation, reversed-phase chromatography, high-resolution mass spectrometry, N-terminal sequencing, and functional and immunological analyses, we reveal an unexpectedly complex venom profile enriched in high-molecular-weight components and extensively processed peptides, with more than 40 venom peptides sequenced by MS/MS and Edman degradation. The data provide evidence for non-canonical proteolytic events, including the generation of peptides from precursor regions not classically associated with mature venom components. In contrast to the venom of Tityus serrulatus, BamazV displays a “hydrolase-rich, neurotoxin-poor” profile, featuring a catalytically active Group III phospholipase A₂ (BamazPLA₂), a highly active hyaluronidase, metalloproteases, low-mass peptides, and potassium channel toxins. Our results suggest a hydrolytic prey-subjugation strategy, and limited cross-reactivity with commercial antivenom highlighted its distinct structural landscape. Overall, this study advances the understanding of venom evolution and proteolytic diversification in underexplored scorpion lineages, positioning B. amazonicus as a valuable model for investigating alternative venom strategies and identifying novel biotechnological scaffolds. Full article

Bone tissue engineering offers a promising alternative to autografts and allografts for treating critical bone defects. Hydrogels, three-dimensional hydrophilic polymer networks, have emerged as leading scaffold materials due to their ability to mimic native extracellular matrix properties while providing tunable biocompatibility, biodegradability, mechanical characteristics, and high water content, enabling nutrient transport and cell viability. These scaffolds can be loaded with bioactive cues, including growth factors, peptides, and nanoparticles, and can deliver stem cells, supporting localised and sustained bone regeneration. Recent advances in hydrogel design have improved osteoinductivity and osteoconductivity through controlled physical, chemical, and mechanical properties, and sophisticated fabrication strategies such as 3D bioprinting and nanostructuring. This review provides a comprehensive overview of hydrogel-based scaffolds for bone tissue engineering, discussing material types, bioactive factor delivery, host tissue interactions, including immune modulation and osteogenic differentiation, and the latest preclinical and clinical applications. Finally, we highlight the remaining challenges and critical design requirements for developing next-generation hydrogels that integrate structural integrity with biological functionality. Full article

Background/Objectives. Antibiotic resistance is an escalating global health concern, highlighting the need for innovative antibacterial strategies beyond traditional drugs. GroEL, a highly conserved bacterial chaperonin essential for protein folding and stress tolerance, represents a promising but underexplored therapeutic target. This study aimed to identify short peptides capable of binding GroEL monomers and potentially altering their function, with the long-term goal of disrupting bacterial survival mechanisms. Methods. A phage display screening of a 12-mer peptide library was performed against purified GroEL monomers, yielding five candidate peptides (G1–G5). Their interactions with GroEL were analyzed through molecular docking and molecular dynamics simulations using three-dimensional GroEL structures (1MNF, 1XCK, 8S32). Stability of binding and interaction profiles were assessed through molecular dynamics-based analyses and MM/GBSA free energy calculations. Results. Peptides G4 and G5 displayed the most stable and energetically favorable interactions, with G4–8S32 showing the strongest binding (−116.68 kcal/mol). These peptides localized near inter-subunit interfaces, suggesting potential interference with GroEL oligomerization or allosteric transitions, which are critical for its biological function. Conclusions. Our findings demonstrate that short peptides can stably bind GroEL and potentially modulate its activity. Peptides G4 and G5 represent at our knowledge the first promising scaffolds for developing a novel class of peptide-based antibacterial agents targeting conserved chaperonin systems. This work introduces a new avenue that warrants further experimental validation. Full article

Most respiratory diseases are driven by excessive airway inflammation and oxidative stress, yet current therapies often lack durable efficacy or are unsafe. Host-defense peptides, commonly enriched in animal venoms, offer diverse, target-selective scaffolds for new therapeutics. In this study, we aimed to discover a novel bioactive peptide with therapeutic potential on respiratory tract damage by utilizing Nephila clavata venom gland transcriptome. Using in silico analysis and machine learning-based functional prediction, we designed a peptide, NC-CV, expected to have dual anti-inflammatory and antioxidant activities with low cytotoxicity. In experimental validation, NC-CV improved human bronchial epithelial BEAS-2B cell viability under lipopolysaccharide (LPS) exposure while reducing LPS-induced pro-inflammatory cytokine expression and intracellular reactive oxygen species (ROS) generation. Mechanistic studies and molecular docking simulations indicated that NC-CV prevents toll-like receptor 4 signaling activation, suppressing nuclear factor κB and mitogen-activated protein kinase pathways. Moreover, the antioxidant activity of NC-CV was primarily based on direct intracellular ROS scavenging rather than the induction of endogenous antioxidant enzymes. Collectively, these findings demonstrated that the venom-derived peptide NC-CV disrupts the self-reinforcing cycle involving inflammatory signaling and oxidative stress in airway epithelium, highlighting its promise as a therapeutic candidate for respiratory disease. Full article

Marine ecosystems represent an exceptional reservoir of structurally diverse metabolites with remarkable pharmacological potential. Over the past decades, the exploration of marine organisms has led to the discovery of an ever-expanding number of bioactive compounds. Many of these metabolites display highly original chemical scaffolds that are not typically found in terrestrial organisms, offering new opportunities for drug discovery. Among the most promising applications is their development as anticancer agents, given their ability to interfere with key cellular processes. This review highlights marine natural products currently under investigation in preclinical studies as potential anticancer lead compounds. The molecules are classified into major structural families: aromatic and heterocyclic alkaloids, terpenes and their derivatives, macrolide frameworks, and diverse peptide-based scaffolds, alongside other complex classes (polyketides, thiazole lipids, alkylamino alcohols, and pyrrolocarbazole derivatives). A particular emphasis has been placed on the role of total synthesis over the last decade. Advances in synthetic methodology have not only enabled the production of these complex metabolites in sufficient quantities but have also facilitated the development of novel chemotherapeutic agents. To overcome the challenges of limited natural availability, the advanced synthetic approaches are crucial for harnessing the full therapeutic potential of marine-derived compounds. Full article

Non-small cell lung cancer (NSCLC) remains a leading cause of cancer mortality, with therapeutic resistance posing the primary barrier to durable outcomes. Beyond genetic and epigenetic alterations, amino acid transporter-driven metabolic reprogramming—mediated by LAT1 (SLC7A5), ASCT2 (SLC1A5), and xCT (SLC7A11)—supports tumor proliferation, redox homeostasis, and immune escape. Their preferential expression in NSCLC highlights their potential as therapeutic targets and predictive biomarkers. In parallel, α-particle therapy has gained attention for its capacity to eradicate resistant clones through densely clustered, irreparable DNA double-strand breaks. Astatine-211 (²¹¹At) combines a clinically relevant half-life, high linear energy transfer, and predictable decay scheme, positioning it as a unique candidate among α-emitters. Preclinical studies of ²¹¹At-labeled transporter ligands, particularly LAT1-targeted conjugates, demonstrate potent tumor suppression and synergy with targeted therapy, chemotherapy, radiotherapy, immunotherapy, and ferroptosis inducers. Advances in radiochemistry, delivery systems (antibodies, peptides, and nanocarriers), and PET tracers such as [¹⁸F]FAMT and [¹⁸F]FSPG collectively support a theranostic framework for patient stratification and adaptive dosing. By linking transporter biology with α-particle delivery, ²¹¹At-based theranostics offer a mechanistically orthogonal strategy to overcome resistance and heterogeneity in NSCLC. Successful translation will depend on precise dosimetry, scaffold stabilization, and biomarker-guided trial design, enabling progression toward first-in-human studies and future integration into multimodal NSCLC therapy. Full article

Background/Objectives: The cell surface proteoglycan glypican-3 (GPC3) is reportedly overexpressed in hepatocellular carcinoma (HCC) tissues, but not in benign liver tissues, rendering this protein a potential target for radionuclide theranostic approaches. Peptides are generally a promising class of targeting molecules for the development of radioligands because they combine straightforward synthetic access with favorable pharmacokinetics. Among the published peptides with disclosed structures, one of the most promising radioligands is [¹⁸F]AlF-NOTA-TJ12P2, which has a reported comparably high binding affinity to GPC3 and a high hydrophilicity. In this study, we aimed to design novel GPC3-targeting radioligands based on the TJ12P2 peptidic scaffold. Methods: Peptides were synthesized on solid phase using an Fmoc protecting group strategy. For comparative investigations, the reference nanobody HN3 was expressed in E. coli, isolated and subsequently modified with NODA-GA or SulfoCy3. The binding of native peptides, scrambled variants and reference nanobodies to GPC3 was investigated by surface plasmon resonance (SPR) interaction analysis, and fluorescently labeled versions of peptides and nanobodies were used for fluorescence microscopy in HepG2 (GPC3+) or SK Hep1 (GPC3−) cells. The chelator-bearing peptides were radiolabeled with gallium-67 and their stability towards radiolysis and in human serum was investigated. The binding of radiolabeled peptides and nanobodies to HepG2 cells was assessed in real-time ligand binding experiments. Results: The synthesized native peptides did not exhibit binding towards GPC3 in SPR interaction analyses, and the observed response was comparable to that of the scrambled variants at equal concentrations. Additionally, no binding to or uptake of the fluorescent constructs into cells was observed with fluorescence microscopy regardless of cellular GPC3 expression level. In real-time radioligand binding experiments, very fast association and dissociation of the gallium-67 labeled peptides to GPC3 positive HepG2 cells was observed, suggesting either extremely fast binding kinetics or unspecific binding of the peptides. Conclusions: Taken together, these findings suggest that the peptide TJ12P2 lacks specific binding to GPC3 in vitro and might not serve as a basis for the development of radioligands targeting GPC3. Full article

As an economically important species endemic to the upper tributaries of Yangtze River in China, long-finned gudgeon fish (Rhinogobio ventralis) has been classified as endangered due to habitat destruction and population decline. In this study, we constructed a chromosome-level genome assembly of R. ventralis by integration of MGI, PacBio and Hi-C sequencing technologies. The final genome assembly was 1015.9 Mb in length (contig N50: 25.91 Mb; scaffold N50: 39.99 Mb), and 97.19% of the haplotypic genome sequences were anchored onto 25 chromosomes. Repetitive elements accounted for 51.00% of the entire genome assembly. A total of 23,220 protein-coding genes were predicted for the assembled genome, of which 99.79% were functionally annotated. Genome evaluation revealed 99.72% completeness for the genome assembly. Through genome-wide prediction of antimicrobial peptides (AMPs), we identified and localized 561 putative AMP-containing genes in the R. ventralis genome. These genes were further classified into 185 distinct functional categories based on public databases, with the top ten components of Penetratin (21.74%), Histone (5.70%), E6AP (4.09%), Scolopendin 1 (2.67%), D38 (2.31%), WBp-1 (2.13%), Defensin (2.13%), Claudin 1 (1.96%), Azurocidin (AZU1, 1.78%), and Ubiquitin (1.60%). Our data presented here provide a potential genetic resource for promoting fundamental research and wild population conservation of this endangered fish species. Full article