Visible-light-induced acridinium-catalyzed selective N-dealkylation of N-heterocycles

We have developed an efficient and general strategy for N-chlorosuccinimide (NCS)-promoted N-dealkylation of aza-heterocycles via acridinium-photocatalyzed electron transfer and hydrogen atom transfer. This approach effectively obviates the need for transition metal catalysis and features wide substrate scope as well as exclusive chemo-selectivity. Remarkably, the method allowed the deprotection of the privileged but stable N-alkyl group, thus filling a gap in the practical N-dealkylation of N-heteroaromatics.

Proteolysis targeting chimeras (PROTACs) in oncology: a review of patents and regulatory considerations

INTRODUCTION

Proteolysis Targeting Chimeras (PROTACs) represents a groundbreaking advancement in drug discovery and targeted protein degradation. Unlike traditional small-molecule inhibitors, PROTACs leverage the cell's natural protein degradation machinery to selectively degrade pathogenic proteins, offering significant therapeutic potential for previously undruggable targets and complex diseases such as cancer and neurodegenerative disorders. Understanding the regulatory landscape governing their approval is crucial as their development accelerates.

AREAS COVERED

This review provides an overview of recent patents, regulatory considerations, emerging concerns, and future perspectives of PROTACs in cancer management.

EXPERT OPINION

From a regulatory perspective, PROTACs present unique challenges and opportunities. Their dual-functional nature requires a nuanced approach to classification and approval, blending small-molecule and biologic regulatory frameworks. Specific guidelines addressing pharmacokinetic and pharmacodynamic profiles are needed. Comprehensive preclinical evaluation and robust clinical trial designs are essential to manage off-target effects and immunogenic responses. The collaboration between regulatory bodies, academia, and industry is crucial for establishing a clear pathway for PROTAC approval. Future considerations must account for advancements in PROTAC technology to ensure safe and effective therapies reach patients. While PROTACs hold immense promise, their regulatory journey requires tailored guidelines and rigorous evaluation to realize their full potential.

Ortho-functionalization of a 211At-labeled aryl compound provides stabilization of the C-At bond against oxidative dehalogenation

Targeted alpha therapy appears to be a promising approach in nuclear medicine for the treatment of cancers. Thanks to its appropriate physical properties, 211At is an ideal candidate compared with other alpha emitters. Because of its enigmatic nature, the chemical element astatine is the subject of growing interest to better understand its radiochemistry. The application of 211At in the clinic, which has shown good therapeutic results, is however still hampered. Stability issues of 211At-radiolabeling were quickly encountered in early preclinical trials and later confirmed in the clinic that mainly studied 211At-radiopharmaceuticals labeled by formation of an astatobenzamide derivative. Recent studies have shed light on the deastatination mechanisms encountered in vivo, in particular potential oxidative mechanisms that may weaken the carbon-astatine bond formed during the radiolabeling. In this work, we show that ortho-functionalization of astatoaryl compounds with benzyl alcohols protects radiolabeling from deastatination in a strongly oxidizing and acidic medium, as well as in liver microsomal media reproducing in vivo deastatination via cytochrome P450 (CYP450) mediated mechanisms. Our results open the way to the rational design of new 211At-aryl-based compounds with improved stability.

Iron-based nanozymes induced ferroptosis for tumor therapy

Iron-based nanozymes are an emerging class of nanomaterials demonstrating significant potential in tumor therapy by inducing ferroptosis-a regulated form of cell death marked by iron-mediated lipid peroxidation (LPO). These nanozymes exhibit unique enzymatic activities, including peroxidase, oxidase, and glutathione oxidase-like functions, enabling them to generate reactive oxygen species (ROS) and disrupt tumor microenvironment homeostasis. Leveraging Fenton chemistry, iron-based nanozymes amplify oxidative stress within tumor cells, thereby overcoming therapeutic challenges such as drug resistance and nonspecific toxicity. Despite significant advancements, the precise mechanisms by which iron-based nanozymes influence ferroptosis and their therapeutic efficacy remain underexplored. This review systematically categorizes these iron-based nanozymes, including iron oxides, single-atom enzymes, and metal-organic frameworks. We further elucidate their mechanisms in enhancing ferroptosis, focusing on their structural attributes, ROS generation pathways, and their enzymatic activities. Additionally, we summarized their biochemical applications alongside challenges in biosafety, nanozyme specificity, and advanced design and analysis approaches essential for maximizing their therapeutic efficacy.

Development of multifunctional fluorescence-emitting potential theranostic agents for Alzheimer's disease

The cholinergic deficits and amyloid beta (Aβ) aggregation are the mainstream simultaneously observed pathologies during the progression of Alzheimer's disease (AD). Deposited Aβ plaques are considered to be the primary pathological hallmarks of AD and are contemplated as promising diagnostic biomarker. Herein, a series of novel theranostic agents were designed, synthesised and evaluated against cholinesterase (ChEs) enzymes and detection of Aβ species, which are major targets for development of therapeutics for AD. Among all the tested compounds against ChEs enzymes, compound/probe 39 & 43 exhibited potent inhibitory activities. Its excellent BBB permeability was anticipated in PAMPA assay. Measurement of fluorescent properties showed emission maxima (λemm) in between 530 and 550 nm in distinct organic solvent except in the most polar solvent i.e., PBS (10 % DMSO), where broad absorption (λabs of 440 nm) and emission spectrum (λemm of 640 nm) was observed. The relative fluorescence quantum yield of probe 39 in methanol was found to be 0.17. The increase in fluorescence intensity displayed by the probe 39 upon binding with Aβ aggregates in the in vitro assay, and produced high apparent binding constant. Further, it's binding affinity towards Aβ1-42 aggregates was validated on the basis of colocalization with thioflavin T (ThT). A significant enhancement in the fluorescence lifetime of probe 39 on binding with Aβ aggregates was observed in time-correlated single-photon counting (TCSPC) analysis (10.00 ± 1.12 ns) and fluorescence lifetime imaging microscopy (FLIM) imaging (11.53 ± 0.01 ns). Furthermore, acute oral toxicity studies signified the safety profile of lead probe 39. The in-vivo behavioural studies demonstrated a substantial improvement of cognitive and special memory impairment in the scopolamine-induced cognitive deficit in mice model on the administration of compound 39 at a dose of 20 mg/kg. The AChE inhibitory potential and antioxidant property of lead probe 39 were further accessed with ex vivo biochemical analysis. Together, our findings suggest Probe 39 as a promising theranostic agent for the AD.

Extraction, isolation, identification and bioactivity of anthraquinones from Aspergillus cristatus derived from Fuzhaun brick tea

Aspergillus cristatus, a probiotic fungus isolated from Fuzhuan brick tea (FBT), produces various valuable but uncharacterized secondary metabolites. We hypothesized that diverse anthraquinones metabolized by A. cristatus possess promising bioactivities and influence fermentation process of FBT. In this study, five benzaldehyde derivatives, three indolediketopiperazine alkaloids and twelve anthraquinones were profiled from A. cristatus, and the methods for extracting and purifying anthraquinones were established. Twelve anthraquinones were identified as (+)-variecolorquinone A, fallacinol, (+)1-O-demethylvariecolorquinone A, dermolutein, citreorosein, endocrocin, questin, rubrocristin, emodin, catenarin, physcion and erythroglaucin, providing clues for deducing their biosynthetic pathways. Functionally, these compounds demonstrated antioxidant, anti-inflammatory and antibacterial effects. Notably, emodin, catenarin, citreorosein and erythroglaucin exhibited remarkable anti-inflammatory activity. Furthermore, the antibacterial metabolites, especially emodin and catenarin, demonstrated potent antibacterial properties against Escherichia coli and Staphylococcus aureus, elucidating that A. cristatus antagonized pathogens during FBT production. Collectively, these anthraquinones hold promise as stable colorants and effective preservatives in food industry.

Advancing Biosensing Frontiers Through Gold Nanoparticle Engineering: Synthesis Strategies and Detection Paradigms

Gold Nanoparticles (GNPs) play a pivotal role in nanobiotechnology because of their distinct physicochemical traits, such as optical properties, compatibility with biological systems, and their ability to be easily functionalized. The top-down and bottom-up approaches are for the synthesis of GNPs. There are various chemical, physical, and green synthesis techniques, such as chemical reduction, seed-mediated growth, physical ablation method, pyrolysis, sputtering, etc. are some methods for the synthesis of GNPs. The use of plants, algae, fungi, and other microorganisms has recently arisen as a new approach for the eco-friendly synthesis with precise control over NP size, shape, and surface properties. The functionalization strategies involving biomolecules, polymers, and ligands enhance their stability and target specificity, facilitating their integration into biosensors. The detection of biomolecules, pathogens, and environmental toxins with high sensitivity and accuracy is facilitated by multiple signals such as localized surface plasmon resonance (LSPR), alterations in color, and electrochemical characteristics. Furthermore, their role in point-of-care diagnostics, drug delivery, and imaging underscores their versatility in biomedical applications. This review provides a comprehensive overview of recent advancements in the synthesis, functionalization, and GNPs-based biosensors. In addition, the review highlights recent advancements, challenges, and future prospects of GNPs in biosensing and nanomedicine, offering an understanding of diagnostics and therapeutic monitoring. The key challenges include stability, reproducibility, and scalability, and the future focuses on green synthesis with enhanced sensitivity and multiplexed biosensing applications.

Converting indoprofen to moderate selective COX-2 inhibitors: Design, synthesis and biological evaluation

Moderate COX-2 inhibitors with favorable safety profiles might benefit the treatment of ulcerative colitis. Herein, biochemical differences between COX-1 and COX-2 enzymes were exploited to identify a strategy for converting the nonsteroidal anti-inflammatory drug indoprofen into moderately selective COX-2 inhibitors through the installation of amides (7a-7y) and sulfonamides (8a-8g) at its C-7 position. The cyclooxygenase inhibition assays dementated that compounds 7m, 7x, 7y, and 8d, displayed moderate selectivity towards the COX-2 enzyme (selectivity indexes = 10.57-18.35) compared with indoprofen (selectivity index = 0.78) and celecoxib (selectivity index = 57.47). 7y was also more effective in anti-inflammatory than celecoxib, observed by inhibiting NO, TNF-α, and IL-6 towards lipopolysaccharide-induced murine macrophages. An absorption, distribution, metabolism, and excretion study revealed that the compounds were promising new oral anti-ulcerative colitis agents. More importantly, 7y exhibited better gastric safety profiles than indoprofen in vivo. 7y also strongly protects against DSS-induced ulcerative colitis, evidenced by significantly mitigating histological damage. The study suggested that the structural modification at the C-7 position of indoprofen can reduce its COX-1 inhibition while converting it into a moderately selective COX-2 inhibitor; compound 7y represents a promising lead for treating ulcerative colitis with minimal gastrointestinal side effects.

Intelligent hydrogel-based dressings for treatment of chronic diabetic wounds

Diabetic wounds represent a significant challenge in the medical field, significantly impacting patient quality of life and imposing a heavy burden on healthcare systems. Intelligent hydrogel dressings have attracted significant attention in diabetic wound treatment due to their unique properties. This review systematically explores the three main categories of intelligent hydrogels (natural, synthetic, and composite), dissecting their composition, structure, and the mechanisms that enable their intelligent responses. The crucial roles of these dressings in maintaining a moist wound environment, efficiently absorbing exudate, and precisely delivering drugs are expounded. Moreover, their application advantages in combating bacteria and infections, regulating inflammation and immunity, promoting angiogenesis and tissue regeneration, as well as enabling real-time monitoring and personalized treatment, are explored in depth. Additionally, we discuss future research directions and the prospects for personalized precision medicine in diabetic wound care, aiming to inspire innovation and provide a comprehensive theoretical basis for the development of next-generation intelligent dressings.

The first example of white-light emission based on pyrimido[4',5':4,5]thieno[2,3-d]pyrimidine moiety: Synthesis, photophysical, and antimicrobial studies

A series of new AIE systems based on the pyrimidothienopyrimidine skeleton were efficiently synthesized and fully characterized. These compounds exhibited weak emission in solution but strong solid-state fluorescence with a red shift. Notably, compound 16 displayed unique white-light emission from a single-component system and tunable emission colors in DMF/water mixtures. This dual emission behavior, arising from AIE and excimer formation, is unprecedented for pyrimidothienopyrimidine derivatives. Although compounds 9a and 9b exhibited AIEE behavior, compounds 15c and 18 demonstrated AIE behavior, with significantly enhanced fluorescence intensity upon water addition. Moreover, most synthesized compounds exhibited moderate to strong antimicrobial activity against various bacterial and fungal strains, suggesting their potential for biological applications.

Synthesis, antimicrobial evaluation, HPLC-based compound accumulation and docking studies of 2-methoxybenzoyl thioureas

INTRODUCTION

In this study, we presented the synthesis, antimicrobial activity, High Performance Liquid Chromatography (HPLC)-based compound accumulation and molecular docking of 2-methoxybenzoyl substituted thiourea derivatives.

MATERIALS AND METHODS

The antimicrobial activity of a total of eight synthesized compounds was evaluated against seven species of bacteria and fungi. HPLC-based compound accumulation assay, molecular docking, in silico toxicity and ADME analyses were performed for selected compounds for further evaluation of compound activity relationship.

RESULTS AND DISCUSSION

The compounds exhibited greater activity against fungi than bacteria, with compounds 1b, 1c, 1d, and 1g showing particularly strong activity against Candida species. Compounds 1a, 1b, 1d, and 1h that had varying biological activities were selected for further analyses. Compounds 1a, 1b, 1d, and 1h accumulated intracellularly reaching up to 36.77% within 1 hours. Molecular docking studies revealed compatible interactions among the compounds in comparison to their varying biological activities. Additionally, all compounds had low toxicity and showed no physicochemical violations when compared to Lipinski's rule of five.

CONCLUSION

The results suggest that optimizing the position of substituents on the phenyl rings of acyl thioureas could enhance the antimicrobial activity of our compounds.

Design, synthesis, docking, DFT, and MD simulation studies of new piperazine, 1,3,4-oxadiazole, and quinoline conjugates: A search for potent antiepileptic agents

In this study, novel substituted 2-(5-(2-phenylquinolin-4-lyl)-1,3,4-oxadiazol-2-ylthio)-1-(4-phenylpiperazine-1-yl) ethanones (11a-i) were synthesized and assessed for their anticonvulsant potential. The structures of the synthesized compounds were confirmed through FT-IR, 1H NMR, 13C NMR, and mass spectrometry. In vivo, anticonvulsant investigations were performed using the maximal electroshock seizure (MES) and subcutaneous pentylenetetrazol (scPTZ) induced epilepsy animal models. Compounds 11b, 11e, and 11 h demonstrated the most promising action against the induced seizures. To prove that the synthetic derivatives' ability to prevent seizures is not caused by any depression brought on by the use of synthesized derivatives, antidepressant activity has been conducted via a forced swim test (FST). In addition, in silico evaluations comprising ADME predictions, molecular docking, and molecular dynamics simulations on GABAA receptors were also performed to determine the pharmacokinetic profiles, binding mode, orientation, and stability of synthesized compounds at the active sites of the targets. The electronic structure of synthesized compounds was also described by density functional theory (DFT) through various reactivity descriptors such as HOMO, LUMO, electron affinity, ionization potential, chemical potential, and global softness. The results of computational studies reinforced the findings of in vivo screening. In summary, this study introduces a promising class of piperazine-1,3,4-oxadiazole-quinoline hybrids with significant antiepileptic properties, warranting further pharmacological exploration for their potential clinical applications.

PAF1C-mediated activation of CDK12/13 kinase activity is critical for CTD phosphorylation and transcript elongation

The transcription cycle is regulated by dynamic changes in RNA polymerase II (RNAPII) C-terminal domain (CTD) phosphorylation, which are crucial for gene expression. However, the mechanisms regulating the transcription-specific cyclin-dependent kinases (CDKs) during the transcription cycle remain poorly understood. Here, we show that human CDK12 co-phosphorylates CTD Serine2 and Serine5. This di-phosphorylated Serine2-Serine5 CTD mark may then act as a precursor for Serine2 mono-phosphorylated CTD through Serine5 de-phosphorylation. Notably, CDK12 is specifically regulated by association with the elongation-specific factor PAF1 complex (PAF1C), in which the CDC73 subunit contains a metazoan-specific peptide motif, capable of allosteric CDK12/cyclin K activation. This motif is essential for cell proliferation and required for normal levels of CTD phosphorylation in chromatin, and for transcript elongation, particularly across long human genes. Together, these findings provide insight into the mechanisms governing RNAPII phospho-CTD dynamics that ensure progression through the human transcription cycle.

Accurate Diagnosis of Pseudomonas aeruginosa Is Critical to Mitigating Development of Antibiotic Resistance

Background: The accurate and rapid diagnosis of infections is critical for effective and timely treatment. Misdiagnosis often leads to the prescription of antibiotics not targeting the causing agent of infection and thus be the possible development of multidrug resistance. This collectively worsens the condition and might lead to unnecessary intervention or death. The abundance of Pseudomonas spp. in healthcare-settings and the environment may lead to the inaccurate diagnosis of P. aeruginosa, making the treatment of its infections challenging. P. aeruginosa is a Gram-negative, opportunistic pathogen commonly linked to healthcare-associated infections. Its pathogenicity is attributed to several virulence factors correlated to enhanced survivability and colonization, invasion of the host tissues, and the development of multidrug resistance. When advanced diagnostic facilities are limited or unaffordable, the prescription of antibiotics solely relies on identifying the bacteria by culture-based methods. Objectives: This study aims to validate the accuracy of diagnosis of fifty clinical isolates preidentified as P. aeruginosa in three healthcare facilities in Jordan. Methods: The isolates were from infected areas of patients, including skin, wounds, ears, urine, and peritoneal cavities. Morphological and biochemical tests were performed, and the validation relied on the polymerase chain reaction (PCR) amplification of the 16S ribosomal ribonucleic acid (rRNA) gene. This molecular method is affordable for medical facilities with limited finances in contrast to advanced high-cost techniques. Results: The PCR confirmed that only 60% of the isolates were P. aeruginosa. All the confirmed isolates could produce different pigments and form biofilms. Conclusions: The high percentage of isolates mistakenly identified as P. aeruginosa raises concern about the suitability of prescribed antibiotics. The present study strongly recommends using advanced molecular methods to identify the pathogens. If conventional methods remain the only diagnostic option, this study recommends frequent external validation for tests in addition to performing an antibiotic susceptibility test to pinpoint the effective antibiotics against biofilm-producing P. aeruginosa.

Solvatochromic fluorophores based on 6-fluoro-2-(aryl)quinoline-4-carboxylic acids: Synthesis, optical studies and evaluation of their antimicrobial and larvicidal properties

6-Fluoro-2-(aryl)quinoline-4-carboxylic acids 1-11 were synthesized via Pfitzinger reactions between 5-fluoroisatin and methyl aryl ketones. The molecules were studied regarding the impact of their substituent patterns (a-e) on their optical and bioactivity properties. All compounds were fluorescent in solution and had significant solvatochromic behavior, measured in tetrahydrofuran, dichloromethane, dimethylsulfoxide, acetonitrile, methanol, and water at different pHs. Compounds emitted in a broad spectral range from ultraviolet to green, with quantum efficiencies, varying from very weak (ex.: <0.5 % for 1a in DMSO and MeOH) to moderate-strong (∼35 % for 11e in dichloromethane). A biomonitoring of the synthetized compounds reveals antimicrobial and larvicidal (Aedes aegypti mosquitoes) profile. Gram-positive bacterial and fungal species showed greater sensitivity to the 11e, that presented both bactericidal and fungicidal nature. This compound with a methylenedioxy substituent showed favourable interactions with Dehydrosqualene synthase (DQS) and Squalene synthase (SQS), well-validated antimicrobial targets, considering key residues in the complex formation. The molecule also presented a good larvicidal profile, ranking second in terms of significant LC50 values. Thus, 11e has demonstrated an advantage scaffold for future biological tests in other organisms or at the cellular level.

A transition metal-free [3 + 2] cycloaddition approach for the efficient synthesis of trisubstituted pyrrole derivatives from β-chlorovinyl aldehydes

A transition metal-free, Cs2CO3-promoted approach has been devised for the efficient synthesis of nitrile-substituted novel pyrrole derivatives from β-chlorovinyl aldehydes. Interestingly, the strategy was also found to be applicable to the synthesis of chromenone-fused pyrrole derivatives. The reaction proceeded through [3 + 2] cycloaddition between diversely substituted aryl propiolonitriles and toluenesulphonylmethyl isocyanide in DMF at ambient temperature. This approach offers several advantages including the use of inexpensive and readily available starting materials, wide substrate scope, operational simplicity, short reaction times (15 min-1.5 h), high atom economy, sustainable reaction conditions and high product yields. The strategy has been found to be amenable for gram-scale synthesis, and the scope of the strategy has been demonstrated for the synthesis of a diverse library of novel pyrrole derivatives with yields of up to 91%. The generated pyrrole derivatives are amenable for late-stage functionalisation and functional group interconversion.

Bioinspired Methionine-Selective Desulfurization Editing of Peptides via the Photocatalysis Strategy

S-Adenosylmethionine (SAM) frequently functions as a cofactor or precursor for enzymes, initiating an array of radical reactions in biological systems. In contrast with the conventional 5'-deoxyadenosyl (dAdo) radical pathway, which proceeds via homolytic cleavage of the S-C(5') bond of SAM, the Dph2 enzyme provides an alternative 3-amino-3-carboxypropyl (ACP) radical pathway through breaking the S-C(γ) bond. Inspired by this distinctive bond cleavage mode, we have developed a chemically induced pathway to generate an ACP-type radical intermediate on methionine-based sulfonium. This strategy presents a novel desulfurization conjugation mode for methionine modification, diverging from previous approaches that conjugate onto the sulfur atom or the adjacent methyl group of methionine. The versatility of this strategy is demonstrated by the efficient functionalization of various peptides and peptide macrocyclizations. Density Functional Theory (DFT) calculations provide further insights into the mechanism of this desulfurization reaction, explaining the exceptional selectivity of homolytic cleavage of the S-C(γ) bond of methionine-based sulfonium. The successful implementation of this novel desulfurization strategy represents a substantial advancement in the understanding of sulfonium-based intramolecular radical substitution reactions and provides new opportunities for the functionalization of biomolecules, thereby fostering progress in interdisciplinary research.

Terminal complement complexes with or without C9 potentiate antimicrobial activity against Neisseria gonorrhoeae

The complement cascade is a front-line defense against pathogens. Complement activation generates the membrane attack complex (MAC), a 10-11 nm diameter pore formed by complement proteins C5b through C8 and polymerized C9. The MAC embeds within the outer membrane of Gram-negative bacteria and displays bactericidal activity. In the absence of C9, C5b-C8 complexes can form 2-4 nm pores on membranes, but their relevance to microbial control is poorly understood. Deficiencies in terminal complement components uniquely predispose individuals to infections by pathogenic Neisseria, including N. gonorrhoeae (Gc). Increasing antibiotic resistance in Gc makes new therapeutic strategies a priority. Here, we demonstrate that MAC formed by complement activity in human serum disrupts the Gc outer and inner membranes, potentiating the activity of antimicrobials against Gc and re-sensitizing multidrug-resistant Gc to antibiotics. C9-depleted serum also exerts bactericidal activity against Gc and, unlike other Gram-negative bacteria, disrupts both the outer and inner membranes. C5b-C8 complex formation potentiates Gc sensitivity to azithromycin and ceftriaxone, but not lysozyme or nisin. These findings expand our mechanistic understanding of complement lytic activity, suggest a size limitation for terminal complement-mediated enhancement of antimicrobials against Gc, and suggest that complement manipulation can be used to combat drug-resistant gonorrhea.

IMPORTANCE

The complement cascade is a front-line arm of the innate immune system against pathogens. Complement activation results in membrane attack complex (MAC) pores forming on the outer membrane of Gram-negative bacteria, resulting in bacterial death. Individuals who cannot generate MAC are specifically susceptible to infection by pathogenic Neisseria species including N. gonorrhoeae (Gc). High rates of gonorrhea, its complications like infertility, and high-frequency resistance to multiple antibiotics make it important to identify new approaches to combat Gc. Beyond direct anti-Gc activity, we found that the MAC increases the ability of antibiotics and antimicrobial proteins to kill Gc and re-sensitizes multidrug-resistant bacteria to antibiotics. The most terminal component, C9, is needed to potentiate the anti-Gc activity of lysozyme and nisin, but azithromycin and ceftriaxone activity is potentiated regardless of C9. These findings highlight the unique effects of MAC on Gc and suggest novel translational avenues to combat drug-resistant gonorrhea.

Asymmetric aza-Friedel-Crafts reaction of newly developed ketimines: access to chiral indeno[1,2-b]quinoxaline architectures

The functionalized 11-amino-indeno[1,2-b]quinoxaline scaffold is a pivotal structural motif in diverse bioactive compounds. In this study, we developed a chiral phosphoric acid catalysed enantioselective aza-Friedel-Crafts reaction between indeno[1,2-b]quinoxalin-11-imines and indoles. This methodology enables the synthesis of chiral hybrid architectures incorporating both 11-aminoindeno[1,2-b]quinoxaline and indole moieties, achieving exceptional synthetic efficiency (up to 99% yield) with outstanding stereocontrol (up to 99% ee).

P-Glycoprotein as a Therapeutic Target in Hematological Malignancies: A Challenge to Overcome

P-glycoprotein (P-gp), a transmembrane efflux pump encoded by the ABCB1/MDR1 gene, is a major contributor to multidrug resistance in hematological malignancies. These malignancies, arising from hematopoietic precursors at various differentiation stages, can manifest in the bone marrow, circulate in the bloodstream, or infiltrate tissues. P-gp overexpression in malignant cells reduces the efficacy of chemotherapeutic agents by actively expelling them, decreasing intracellular drug concentrations, and promoting multidrug resistance, a significant obstacle to successful treatment. This review examines recent advances in combating P-gp-mediated resistance, including the development of novel P-gp inhibitors, innovative drug delivery systems (e.g., nanoparticle-based delivery), and strategies to modulate P-gp expression or activity. These modulation strategies encompass targeting relevant signaling pathways (e.g., NF-κB, PI3K/Akt) and exploring drug repurposing. While progress has been made, overcoming P-gp-mediated resistance remains crucial for improving patient outcomes. Future research directions should prioritize the development of potent, selective, and safe P-gp inhibitors with minimal off-target effects, alongside exploring synergistic combination therapies with existing chemotherapeutics or novel agents to effectively circumvent multidrug resistance in hematological malignancies.

Nicotinamide N-Methyltransferase (NNMT) and Liver Cancer: From Metabolic Networks to Therapeutic Targets

Hepatocellular carcinoma (HCC), the predominant form of primary liver cancer, remains a global health challenge with limited therapeutic options and high mortality rates. Despite advances in understanding its molecular pathogenesis, the role of metabolic reprogramming in HCC progression and therapy resistance demands further exploration. Nicotinamide N-methyltransferase (NNMT), a metabolic enzyme central to NAD+ and methionine cycles, has emerged as a critical regulator of tumorigenesis across cancers. However, its tissue-specific mechanisms in HCC-particularly in the context of viral hepatitis and methionine cycle dependency-remain understudied. This review systematically synthesizes current evidence on NNMT's dual role in HCC: (1) driving NAD+ depletion and homocysteine (Hcy) accumulation via metabolic dysregulation, (2) promoting malignant phenotypes (proliferation, invasion, metastasis, and drug resistance), and (3) serving as a prognostic biomarker and therapeutic target. We highlight how NNMT intersects with epigenetic modifications, immune evasion, and metabolic vulnerabilities unique to HCC. Additionally, we critically evaluate NNMT inhibitors, RNA-based therapies, and non-pharmacological strategies (e.g., exercise) as novel interventions. By bridging gaps between NNMT's molecular mechanisms and clinical relevance, this review provides a roadmap for advancing NNMT-targeted therapies and underscores the urgency of addressing challenges in biomarker validation, inhibitor specificity, and translational efficacy. Our work positions NNMT not only as a metabolic linchpin in HCC but also as a promising candidate for precision oncology.

The potential of targeting autophagy-related non-coding RNAs in the treatment of lung cancer

Lung cancer is the most prevalent malignant tumor worldwide and remains the leading cause of cancer-related mortality. Despite advances in treatment development, lung cancer patients often face poor quality of life and low survival rates. Increasing evidence highlights the significant roles of autophagy and non-coding RNAs (ncRNAs) in the initiation, progression, and therapeutic response of lung cancer. Autophagy and ncRNAs can function as both tumor-promoting and tumor-suppressing factors in lung cancer. Therefore, investigating the roles of autophagy and ncRNAs in lung cancer provides valuable insights into its pathophysiology. At the same time, non-coding RNA also plays an important role in regulating autophagy. This study reveals that autophagy affects the occurrence and development of lung cancer through multiple pathways. Then, we also studied that in lung cancer, ncRNAs (e.g., lncRNAs, miRNAs, circRNAs and piRNAs) can regulate autophagy to promote or inhibit tumorigenesis, metastasis and drug resistance in lung cancer. Finally, the problems and solutions of autophagy and ncRNAs in the treatment of lung cancer were explored. These findings suggest that autophagy and ncRNAs can be potential targets for the treatment of lung cancer.

Easy access to 5-cyanotriazoles via Pd-catalyzed cyanation of 5-iodotriazoles

A straightforward approach for the attachment of a nitrile moiety to the 1,2,3-triazole core has been developed. The protocol is based on the cyanation of 5-iodo-1,2,3-triazoles which are readily accessible by Cu-catalyzed azide-iodoalkyne cycloaddition. Halogen substitution occurs smoothly with KCN as a cyanide source using a Pd(0)-Dpephos catalytic system. The reaction tolerates a variety of functional groups as well as some sensitive heterocyclic scaffolds and affords the target 5-cyano-1,2,3-triazoles in yields of up to 99%. Further transformations of the nitrile group enable an easy preparation of 1,2,3-triazoles bearing diverse moieties, including amides, amines, and some azaheterocycles.

The recent advances in vaccine adjuvants

Vaccine adjuvants, as key components in enhancing vaccine immunogenicity, play a vital role in modern vaccinology. This review systematically examines the historical evolution and mechanisms of vaccine adjuvants, with particular emphasis on innovative advancements in aluminum-based adjuvants, emulsion-based adjuvants, and nucleic acid adjuvants (e.g., CpG oligonucleotides). Specifically, aluminum adjuvants enhance immune responses through particle formation/antigen adsorption, inflammatory cascade activation, and T-cell stimulation. Emulsion adjuvants amplify immunogenicity via antigen depot effects and localized inflammation, while nucleic acid adjuvants like CpG oligonucleotides directly activate B cells and dendritic cells to promote Th1-type immune responses and memory T-cell generation. The article further explores the prospective applications of these novel adjuvants in combating emerging pathogens (including influenza and SARS-CoV-2), particularly highlighting their significance in improving vaccine potency and durability. Moreover, this review underscores the critical importance of adjuvant development in next-generation vaccine design and provides theoretical foundations for creating safer, effective adjuvant.

Green Synthesis, Characterization, and Potential Antibacterial and Anticancer Applications of Gold Nanoparticles: Current Status and Future Prospects

Drug resistance is a serious problem for human health worldwide. Day by day this drug resistance is increasing and creating an anxious situation for the treatment of both cancer and infectious diseases caused by pathogenic microorganisms. Researchers are trying to solve this terrible situation to overcome drug resistance. Biosynthesized gold nanoparticles (AuNPs) could be a promising agent for controlling drug-resistant pathogenic microorganisms and cancer cells. AuNPs can be synthesized via chemical and physical approaches, carrying many threats to the ecosystem. Green synthesis of AuNPs using biological agents such as plants and microbes is the most fascinating and attractive alternative to physicochemical synthesis as it offers many advantages, such as simplicity, non-toxicity, cost-effectiveness, and eco-friendliness. Plant extracts contain numerous biomolecules, and microorganisms produce various metabolites that act as reducing, capping, and stabilizing agents during the synthesis of AuNPs. The characterization of green-synthesized AuNPs has been conducted using multiple instruments including UV-Vis spectrophotometry (UV-Vis), transmission electron microscopy (TEM), scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), DLS, and Fourier transform infrared spectroscopy (FT-IR). AuNPs have detrimental effects on bacterial and cancer cells via the disruption of cell membranes, fragmentation of DNA, production of reactive oxygen species, and impairment of metabolism. The biocompatibility and biosafety of synthesized AuNPs must be investigated using a proper in vitro and in vivo screening model system. In this review, we have emphasized the green, facile, and eco-friendly synthesis of AuNPs using plants and microorganisms and their potential antimicrobial and anticancer applications and highlighted their antibacterial and anticancer mechanisms. This study demonstrates that green-synthesized AuNPs may potentially be used to control pathogenic bacteria as well as cancer cells.

Gold-NHC complexes: from synthetic aspects to anti-cancer activity

Recent advancements in Au(I)-N-heterocyclic carbene (NHC) complexes have demonstrated significant potential for developing novel anticancer agents. These complexes exhibit unique properties, such as a strong affinity for thiol and selenol-containing biomolecules, which enable the selective targeting of cancer cells while minimising effects on healthy tissues. Recent studies have explored various structural modifications to enhance the anticancer efficacy of Au(I)-NHC complexes, including ligand substitution, incorporation of bioactive moieties, and hybridisation with other metal complexes. Mechanistic investigations have revealed that these complexes induce apoptosis through multiple pathways, such as inhibition of thioredoxin reductase (TrxR), disruption of mitochondrial function, and generation of reactive oxygen species (ROS). The introduction of NHC ligands is particularly advantageous, as they provide stability and tunability to the Au(I) centre, allowing for the optimisation of pharmacokinetic and pharmacodynamic properties. Moreover, the emergence of Au(I)-NHC complexes with dual-action mechanisms, combining anticancer activity with antiangiogenic or anti-inflammatory properties, has further broadened their therapeutic potential. This review article highlights the most recent breakthroughs in the design, synthesis, and biological evaluation of Au(I)-NHC complexes, emphasizing their promise as a new class of targeted anticancer therapeutics. While primarily focused on Au(I) complexes, it also includes a brief discussion of selected Au(III) complexes for comparison.

Antimicrobial Activity of a Synthetic Brevibacillin Analog Against Multidrug-Resistant Campylobacter spp

Campylobacter spp. is one of the most prevalent causes of zoonotic foodborne infections associated with diarrhea in humans. The growing threat of antibiotic resistance calls for innovative approaches. The antimicrobial lipopeptide brevibacillin produced by Brevibacillus laterosporus and its synthetic analog brevibacillin Thr1 showed promising activity against Salmonella and E. coli. The latter is a 1602.13 Da positively charged (+3) synthetic peptide of 13 residues that showed reduced cytotoxicity (IC50 of 32.2 µg/mL against Caco-2 cells) and hemolytic activity (1.2% hemolysis at 128 µg/mL) compared to the native peptide. It contains an N-terminal L-isoleucic fatty acid chain and four non-proteinogenic amino acids and ends with valinol at its C-terminus. One key structural modification is the substitution of α,β-dehydrobutyric acid with threonine. We investigated the antimicrobial potential of the synthetic brevibacillin Thr1 analog against a collection of 44 clinical Campylobacter spp. that were obtained from two reference laboratories. Susceptibility testing revealed marked resistance to ciprofloxacin, tetracycline, and ampicillin among the strains, with more than half expressing a multidrug-resistant phenotype. The genomes of the 44 strains were sequenced to study the genes responsible for their antimicrobial resistance. Tetracycline resistance was associated with tet(O), ciprofloxacin resistance with mutations in gyrA and regulatory sequences modulating the expression of an efflux system, and aminoglycoside resistance with genes of the aph family. The brevibacillin Thr1 analog was produced by chemical synthesis, and evaluation of its activity against a subset of clinical strains by microdilution revealed minimum inhibitory concentration and minimum bactericidal concentration ranging from 8 µg/mL to 64 µg/mL. The peptide was active against multidrug-resistant isolates with a bactericidal effect. Of note, despite numerous attempts, it proved impossible to select Campylobacter spp. for resistance to the brevibacillin Thr1 analog. These results underline the potential of lipopeptides, notably brevibacillin, as antimicrobial alternatives against antibiotic-resistant Campylobacter bacterial infections.

Recent Advances in the Development of Antifungal Agents: Beyond Azoles, Polyenes, and Echinocandins

The escalating incidence of antimicrobial resistance to antifungal agents, alongside the emergence of drug-resistant fungal strains, constitutes a significant threat to a potential global fungal pandemic. In response, researchers are intensifying efforts to identify novel antifungal compounds through diverse methodologies. Emerging strategies focus on innovative therapeutic targets that may reduce the risk of resistance development while offering broad-spectrum efficacy against fungal infections. Additionally, these approaches present potential cost-effectiveness and accelerated development timelines. This review systematically categorizes a range of novel antifungal compounds, including antifungal peptides, cationic amphiphiles, small molecules, polymers, and repurposed drugs, based on their efficacy in inhibiting fungal growth and associated virulence factors. These compounds exhibit notable antimicrobial activity across in silico, in vitro, and in vivo systems against various pathogenic fungal strains, with several showing substantial promise for clinical application. Furthermore, the review highlights the limitations of standard antifungals and elucidates the mechanisms by which fungal strains develop resistance. This work aims to engage researchers in the distinctive field of fungal biology and foster the exploration of new antifungal strategies.

High-Throughput Ligand Dissociation Kinetics Predictions Using Site Identification by Ligand Competitive Saturation

The dissociation or off rate, koff, of a drug molecule has been shown to be more relevant to efficacy than affinity for selected systems, motivating the development of predictive computational methodologies. These are largely based on enhanced-sampling molecular dynamics (MD) simulations that come at a high computational cost limiting their utility for drug design where a large number of ligands need to be evaluated. To overcome this, presented is a combined physics- and machine learning (ML)-based approach that uses the physics-based site identification by ligand competitive saturation (SILCS) method to enumerate potential ligand dissociation pathways and calculate ligand dissociation free-energy profiles along those pathways. The calculated free-energy profiles along with molecular properties are used as features to train ML models, including tree and neural network approaches, to predict koff values. The protocol is developed and validated using 329 ligands for 13 proteins showing robustness of the ML workflow built upon the SILCS physics-based free-energy profiles. The resulting SILCS-Kinetics workflow offers a highly efficient method to study ligand dissociation kinetics, providing a powerful tool to facilitate drug design including the ability to generate quantitative estimates of atomic and functional groups contributions to ligand dissociation.

Synthesis and structure-activity relationship of β-carboline derivatives with antifungal activity

To search for and screen out effective antifungal lead compounds applicable to agriculture, a total of 21 tetrahydro-β-carboline derivatives were designed, synthesised, and evaluated for their antifungal activity. Based on biological studies, numerous compounds demonstrate notable antifungal properties in vitro. Specifically, compounds a6 and a20 showed higher efficacy against Sclerotinia sclerotiorum compared to carbendazim, with EC50 values of 16.43 mg/L and 12.72 mg/L, respectively. Additionally, compound a16 exhibited exceptional antifungal activity against both S. sclerotiorum and Botrytis cinerea, achieving identical EC50 values of 12.71 mg/L for both pathogens. The results of this study will give reference for the additional design and structural optimisation of β-carboalkaloids as possible agrochemical lead compounds for plant disease control.

Visible Light-Mediated Preparation of a Key Intermediate Employed in the Synthesis of Zolpidem and Several Analogs

This work describes a protocol being only promoted by visible light for the C3-alkylation of imidazo[1,2-a] pyrimidines and imidazo[1,2-a]pyridines with aryldiazoacetates. Several known and new analogs of a key intermediate employed in previous syntheses of zolpidem have been accessed in good yields. The formal synthesis of this key intermediate was also achieved using this method, but an adjustment of the nature of the alkylating agent was required.

Exploring the synthesis of Ru(II)/Ir(III)/Re(I)/Rh(III)-based complexes as anticancer metallopharmaceuticals: significance, challenges and future perspective

Metal complexes exhibit significant potential in the field of anticancer metallotherapeutics due to their high selectivity toward cancer cells and their effectiveness in targeted drug delivery. This frontier article summarizes recent advances in the synthesis of mono-, bi-, and mixed-metallic Ru(II)/Ir(III)/Re(I)/Rh(III) complexes for anticancer applications. Additionally, various therapeutic approaches and their mechanisms of action in Ru(II)/Ir(III)/Re(I)/Rh(III)-based complexes are discussed. In this study, we provide insights into the contributions of various research groups toward the development of transition metal complexes with promising therapeutic potential. This study also addresses the challenges encountered throughout the designing and application process as well as the future perspectives of these metallopharmaceuticals.

Stachydrine from Natural Foods Alleviates Hyperuricemia by Modulating Renal Urate Transporters and Suppressing Mitochondrial Oxidative Stress

Hyperuricemia (HUA) is a metabolic disease caused by disrupted purine metabolism, characterized by abnormally elevated uric acid (UA) levels. Stachydrine, an alkaloid in natural foods, exhibits multiple biological activities. This study aimed to evaluate the effects of stachydrine on alleviating HUA. An HUA mouse model was established through high-nucleoside diet induction, and stachydrine's effects on UA levels and renal injury were investigated. Our findings revealed that stachydrine enhanced uric acid excretion by upregulating ATP-binding cassette subfamily G member 2 (ABCG2). Furthermore, stachydrine mitigated HUA-induced renal inflammation, mitochondrial oxidative stress and apoptosis. Mechanistically, stachydrine facilitated the nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) by downregulating Kelch-like ECH-associated protein 1 (Keap1), subsequently activating the Keap1/Nrf2 signaling pathway and alleviating local oxidative stress. This study demonstrated the UA-lowering and renoprotective effects of stachydrine, suggesting its potential as a functional food ingredient for mitigating HUA.

Lipoprotein-inspired in situ activatable photo-theranostic nitrobenzoselenadiazole-cholesterol for overcoming glioblastoma

Photo-theranostic materials are designed for both diagnostic imaging and therapeutic applications under specific light sources, particularly in translational medicine. While various photo-theranostic materials have been developed for disease treatment, their cooperative effects on biologically abundant species, such as proteins, have rarely been studied in terms of biological activity. In this work, we disclose a photo-theranostic agent (named NBSD-Chol) based on nitrobenzoselenadiazole (NBSD) and cholesterol (Chol), which is activatable in situ through lipoprotein hybridization. NBSD-Chol demonstrates outstanding potential for cancer imaging and photodynamic therapy (PDT) due to its unique properties, including (i) tumor targeting after oral uptake, (ii) tumor visualization under light irradiation for image-guided surgery, (iii) superior PDT effects, and (iv) downgrading hazard ratios (HR) related to clinically critical proteins. Overall, this work contributes to advancing translational medicine by developing innovative treatments for cancer using visible light, ushering in a new era of intraoperative technology and photodynamic fluorescence-guided surgical agents.

Aptamer-ODN Chimeras: Enabling Cell-Specific ODN Targeting Therapy

Oligonucleotides (ODNs) such as siRNA, saRNA, and miRNA regulate gene expression through a variety of molecular mechanisms and show unique potential in the treatment of genetic diseases and rare diseases, but their clinical application is still limited by the efficiency of the delivery system, especially the problem of the insufficient targeting of extrahepatic tissues. As homologous nucleic acid molecules, aptamers have become a key tool to improve the targeted delivery of ODNs. Aptamer-ODN chimeras can not only bind to multiple proteins on the cell surface with high specificity and selectivity, but they can also internalize into cells. Furthermore, they outperform traditional delivery systems in terms of cost-effectiveness and chemical modification flexibility. This review systematically summarizes the origin and progress of aptamer-ODN chimera therapy, discusses some innovative design strategies, and proposes views on the future direction of aptamer-ODN chimeras.

Redox-Responsive PEO-b-PCL-Based Block Copolymers for Synergistic Drug Delivery and Bioimaging in Cancer Cells

Stimuli-responsive polymer-based nanocarriers enhance the drug delivery efficiency by enabling targeted release at tumor sites. However, integrating therapeutic and diagnostic functions into a single nanoplatform while maintaining control over both remains a significant challenge. This study presents a stimuli-responsive, multifunctional poly(ethylene oxide)-b-poly(ε-caprolactone) (PEO-b-PCL) nanocarrier for combination cancer therapy and bioimaging. The system codelivers chlorambucil (CHL) and methotrexate (MTX) to enhance therapeutic efficacy and overcome multidrug resistance. A redox-responsive disulfide linker enables CHL release in the tumor's glutathione-rich environment, ensuring selective drug activation. Additionally, an aggregation-induced emission (AIE) fluorophore, tetraphenylethylene (TPE), facilitates the monitoring of cellular uptake and drug release. The resulting TPE-(PEO-b-PCL)-S-S-CHL (P3) micelles encapsulated with MTX (P3-MTX) exhibited favorable size, morphology, and enhanced cytotoxicity, demonstrating a synergistic effect in combination therapy. Confocal laser scanning microscopy (CLSM) confirmed intracellular uptake by using TPE-based fluorescence. Thus, these nanocarriers offer a promising theranostic platform for simultaneous cancer treatment and monitoring.

Design and Production of Geranylated Cyclic Peptides by the RiPP Enzymes SyncM and PirF

The growing threat of antibiotic resistance highlights the urgent need for new antimicrobial agents. Nonribosomal peptides (NRPs) are potent antibiotics with complex structures, but generating novel NRP analogues is costly and inefficient. An emerging alternative is using ribosomally synthesized and post-translationally modified peptides (RiPPs), which are gene-encoded, allowing for easier mutagenesis and modification. This study aimed to produce peptides with two key structural elements of many NRP antibiotics: a macrocycle and an N-terminal lipid moiety. The RiPP enzymes SyncM and PirF were employed-SyncM introduced lanthionine or methyllanthionine macrocycles, while PirF incorporated isoprenyl chains to emulate the lipid moieties in NRPs. Both enzymes successfully modified the templates, and their combined use generated lipidated macrocyclic peptides, resembling lipopeptide antibiotics. These findings demonstrate the potential of SyncM and PirF as versatile tools for designing novel gene-encoded NRP mimics, enabling high-throughput screening for new bioactive peptides.

Discovery and optimisation of a covalent ligand for TRIM25 and its application to targeted protein ubiquitination

The tripartite motif (TRIM) family of RING-type E3 ligases catalyses the formation of many different types of ubiquitin chains, and as such, plays important roles in diverse cellular functions, ranging from immune regulation to cancer signalling pathways. Few ligands have been discovered for TRIM E3 ligases, and these E3s are under-represented in the rapidly expanding field of induced proximity. Here we present the identification of a novel covalent ligand for the PRYSPRY substrate binding domain of TRIM25. We employ covalent fragment screening coupled with high-throughput chemistry direct-to-biology optimisation to efficiently elaborate covalent fragment hits. We demonstrate that our optimised ligand enhances the in vitro auto-ubiquitination activity of TRIM25 and engages TRIM25 in live cells. We also present the X-ray crystal structure of TRIM25 PRYSPRY in complex with this covalent ligand. Finally, we incorporate our optimised ligand into heterobifunctional proximity-inducing compounds and demonstrate the in vitro targeted ubiquitination of a neosubstrate by TRIM25.

Oxidovanadium(IV) Porphyrin-Imidazole Complex-Catalyzed One-Pot, Three-Component Green Synthesis of Biologically Active Pyrano[2,3-d]pyrimidine and 4H-Chromene Heterocycles

A β-functionalized porphyrin ligand {H2TPP(Phen)}, has been synthesized and subsequently employed as a dibasic tetradentate ligand in synthesizing its vanadyl complex 2-(1H-imidazo[4,5-f][1,10]phenanthroline-2-yl)-5,10,15,20-tetraphenylporphyrinatooxido-vanadium(IV)[VIVOTPP(Phen)] (1). Comprehensive characterization of the ligand {H2TPP(Phen)} and its vanadyl(IV) complex (1) was achieved through various analytical and spectroscopic techniques, including NMR, ultraviolet-visible (UV-vis), EPR, and MALDI-TOF mass spectrometry and elemental analysis. Electrochemical studies indicated that the free base porphyrin {H2TPP(Phen)} tends to four successive reduction peaks and two oxidation peaks observed in cyclic voltammetry. In contrast, the metalated complex [VIVOTPP(Phen)] displayed two successive reversible reductions and two oxidation peaks. The synthesized vanadyl(IV)-porphyrin complex (1) was further employed as an efficient and reusable catalyst in an environmentally friendly, one-pot, three-component synthesis of biologically and clinically relevant pyrano[2,3-d]pyrimidine (Ca-Ch, Da-Dg) and 4H-chromene (Ga-Gj, Ha-Hj) heterocycles. Based on the current literature regarding one-pot, multicomponent reactions, two distinct and plausible mechanistic pathways are postulated for these transformations. A detailed mechanistic investigation, including the isolation of intermediates and stepwise reaction analysis, revealed that the type of 1,3-dicarbonyl compound used is pivotal in determining the operative mechanistic pathway in these reactions. The current catalytic protocol developed for the synthesis of pyrano[2,3-d]pyrimidine and 4H-chromene heterocycles presents several advantages over existing methodologies, including the use of an eco-friendly solvent (ethanol), high product yields (up to 97%), shorter reaction time scale (30 min), high turnover frequency (TOF) values (up to 14.7 min-1), and excellent catalyst reusability over five catalytic cycles.

Trehalose-Releasing Nanogels: Study on Trehalose Release and Insights into Selected Biologically Relevant Aspects

Trehalose has sparked considerable interest in a variety of pharmaceutical applications as well as in cryopreservation. Recently, there have been growing efforts in the development of trehalose delivery nanocarriers to address the issue of the poor bioavailability of trehalose. The majority of the strategies comprise physical entrapment of trehalose, since its covalent, yet biolabile, conjugation is challenging. Here, we present research on trehalose-releasing nanogels, in which covalent, yet biolabile, conjugation of trehalose was achieved through the co-incorporation of trehalose (meth)acrylate(s) together with hydrophilic primary/secondary acrylamides in one polymeric network. In this case, the primary and secondary amide groups participated in ester hydrolysis in the (meth)acrylate units, making the hydrolysis feasible under physiologically relevant conditions. A set of nanogels with precisely selected compositions were synthesized, characterized, and then studied to evaluate the influence of various structural and environmental factors on the release rate of trehalose. The study also provides insights into some other aspects that are important in view of potential biomedical applications, including specific interactions of nanogels through their terminal α-d-glucopyranosyl moieties from pendant trehalose, protein corona formation, and cellular uptake.

Safety assessment of the ethanolic extract of Siparuna guianensis: Cell viability, molecular risk predictions and toxicity risk for acute and sub-chronic oral ingestion

ETHNOPHARMACOLOGICAL RELEVANCE

The species Siparuna guianensis Aublet (family Siparunaceae) is traditionally used by indigenous peoples and riverine communities in Central and South America to treat migraines, flu, respiratory diseases, fever, pain, edema and inflammatory and infectious diseases. Scientific studies on the species have proven its antiparasitic, insecticidal, antimicrobial, neuroprotective, anti-inflammatory, antioxidant and antinociceptive action. However, the safety profile of the species has not yet been established.

AIM OF THE STUDY

To verify the levels of cytotoxicity, evaluate the molecular toxicological prediction in silico, determine the median lethal dose and verify the possible acute and sub-chronic toxicological effects of S. guianensis in rats.

MATERIALS AND METHODS

After obtaining the aqueous and ethanolic extracts of S. guianensis leaves, the total phenolic content, ABTS radical scavenging activity and cytotoxicity in fibroblasts were evaluated. The ethanolic extract was used in chromatography and in the in silico and in vivo studies. The in silico test evaluated carcinogenicity, mutagenicity and skin irritation. Acute oral toxicity and LD50 were evaluated after the single dose of 2000 mg/kg, with monitoring for 14 days. Sub-chronic toxicity was evaluated at doses of 200, 400 and 800 mg/kg for 30 days. Murinometric parameters, water and food consumption and feed efficiency were evaluated. At the end of the experiments, hematological, biochemical, macroscopic organ and histopathological analyses were performed.

RESULTS

Cell viability was greater than 90 %, without cytotoxicity up to 25 μg/mL. In the in silico predictions, the molecules 2-undecanone, decanoic acid, decanoic acid ethyl ester and 2-tetradecanone showed no risk of carcinogenicity, mutagenicity, skin sensitization or eye irritation. The estimated LD50 was greater than 2000 mg/kg and daily oral use for 30 days was safe up to a limit of 800 mg/kg. The SG2000 group showed weight loss (p<0.01). In the hematological parameters, there was no difference between the groups (p>0.05), but in the biochemical findings, the urea rate was higher in the SG800 group (p<0.05), total proteins were higher in the SG400 group (p<0.05), while alkaline phosphatase was higher in the control group compared to the SG200, SG800 (p<0.01) and SG400 (p<0.05) groups. Triglycerides and VLDL-C were higher in the SG400 group, while non-HDL-C was higher in the SG800 group (p<0.05). The SG2000 group showed the lowest relative weights of the liver, spleen (p<0.05) and lungs (p<0.01), and the SG800 group showed increased weights for the liver (p<0.05) and lungs (p<0.01). Only the animals treated with a single dose of 2000 mg/kg showed histopathological changes in the liver, with slight cytoplasmic and tubular vacuolization in the kidneys.

CONCLUSIONS

The concentration of 25 μg/mL showed no cytotoxicity. Four molecules were detected in silico did not present a risk of carcinogenicity in female mice, nor mutagenicity, skin sensitization or ocular irritation. In rats, the LD50 is greater than 2000 mg/kg. Daily oral use for 30 days at up to 800 mg/kg was considered safe, with no significant hematological or histological alterations. These results may support further studies and pre-clinical trials.

Self-Assembled Cannabigerol-Based Nanoparticles: Design, Synthesis, and Antiproliferative Activity

Background/Objectives: Cannabigerol (CBG) is a non-psychoactive phytocannabinoid with significant therapeutic potential, showing emerging applications in drug delivery. This study aimed to develop and evaluate CBG-conjugated nanoparticles (NPs) incorporating tubulin-targeting drugs to enhance anticancer activity. Methods: CBG was conjugated with N-desacetylthiocolchicine, paclitaxel, and camptothecin using sebacic acid and 4,4'-dithiodibutyric acid as linkers, and nanoparticles were obtained. The NPs were characterized by their stability and size (hydrodynamic diameters < 90 nm). Their antiproliferative activity was assessed in three human tumor cell lines and non-tumorigenic cells. Their cellular uptake and mechanisms of action were investigated via confocal microscopy and cell cycle analysis. Results: The chemical composition of the linkers significantly influenced the antiproliferative effect, with the NPs containing 4,4'-dithiodibutyric acid demonstrating higher activity. Notably, NP3b, formulated with this linker, exhibited up to an 80-fold increase in antiproliferative potency compared to its sebacic acid counterpart (NP3a). In mesothelioma cells (MSTO-211H), NP3b displayed significantly higher cytotoxicity than in non-tumorigenic mesothelial cells (MeT-5A), indicating selectivity for cancer cells. Further analysis in glioblastoma cells confirmed that the NPs retained the microtubule-disrupting effects of their parent drugs. Conclusions: These findings highlight the potential of CBG-based NPs as versatile nanomedicine platforms for targeted cancer therapy. This study underscores the importance of linker chemistry in modulating therapeutic efficacy and supports the development of multifunctional drug delivery systems.

PROTAC Technology as a New Tool for Modern Pharmacotherapy

The publication focuses on the innovative applications of PROTAC (proteolysis-targeting chimera) technology in modern pharmacotherapy, with particular emphasis on cancer treatment. PROTACs represent an advanced therapeutic strategy that enables selective protein degradation, opening new possibilities in drug design. This technology shows potential in the treatment of cancers, viral infections (such as HIV and COVID-19), and chronic diseases including atherosclerosis, Alzheimer's disease, atopic dermatitis, and Huntington's disease. Promising results from clinical studies on the compound ARV-471 confirm the effectiveness of this approach. New types of PROTACs, like TF-PROTAC and PhosphoTAC, are designed to enhance the effectiveness, stability, and absorption of treatment drugs. The conclusions of the review highlight the broad therapeutic potential of PROTACs in various diseases and their relevance for the future of therapies, particularly in oncology.

Antimicrobial resistance and biofilm formation of penile prosthesis isolates: insights from in-vitro analysis

BACKGROUND

Inflatable penile prostheses (IPPs) have been shown to harbor biofilms in the presence and absence of infection despite exposure to various antimicrobials. Microbes persisting on IPPs following antibiotic exposure have not been adequately studied to assess biofilm formation capacity and antibiotic resistance.

AIM

In this study, we aimed to assess these properties of microbes obtained from explanted infected and non-infected IPPS using an in vitro model.

METHODS

35 bacterial isolates were grown and tested against various single-agent or multiple agent antibiotic regimens including: bacitracin, cefaclor, cefazolin, gentamicin, levofloxacin, trimethoprim-sulfamethoxazole, tobramycin, vancomycin, piperacillin/tazobactam, gentamicin + piperacillin/tazobactam, gentamicin + cefazolin, and gentamicin + vancomycin. Zones of inhibition were averaged for each sample site and species. Statistics were analyzed with Holm's corrected, one-sample t-tests against a null hypothesis of 0. Isolates were also allowed to form biofilms in a 96-well polyvinyl plate and absorbance was tested at 570 nm using a microplate reader.

OUTCOMES

Resistance was determined via clinical guidelines or previously established literature, and the mean and standard deviation of biofilm absorbance values were calculated and normalized to the optical density600 of the bacterial inoculum.

RESULTS

Every species tested was able to form robust biofilms with the exception of Staphylococcus warneri. As expected, most bacteria were resistant to common perioperative antimicrobial prophylaxis. Gentamicin dual therapy demonstrated somewhat greater efficacy.

STRENGTHS AND LIMITATIONS

This study examines a broad range of antimicrobials against clinically obtained bacterial isolates. However, not all species and antibiotics tested had standardized breakpoints, requiring the use of surrogate values from the literature. The microbes included in this study and their resistance genes are expectedly biased towards those that survived antibiotic exposure, and thus reflect the types of microbes which might "survive" in vivo exposure following revisional surgery.

CLINICAL TRANSLATION

Despite exposure to antimicrobials, bacteria isolated during penile prosthesis revision for both infected and non-infected cases exhibit biofilm forming capacity and extensive antibiotic resistance patterns in vitro. These microbes merit further investigation to understand when simple colonization vs re-infection might occur.

CONCLUSIONS

Although increasing evidence supports the concept that all IPPs harbor biofilms, even in the absence of infection, a deeper understanding of the characteristics of bacteria that survive revisional surgery is warranted. This study demonstrated extensive biofilm forming capabilities, and resistance patterns among bacteria isolated from both non-infected and infected IPP revision surgeries. Further investigation is warranted to determine why some devices become infected while others remain colonized but non-infected.

Comprehensive synthesis and anticoagulant evaluation of a diverse fucoidan library

Fucoidan, a sulfated glycan derived from brown algae, has garnered significant attention for its anticoagulant properties. However, the structural complexity and heterogeneity of naturally extracted fucoidan have hindered a comprehensive understanding of its structure-activity relationship, limiting the development of fucoidan-based anticoagulant drugs. To address this challenge, we synthesize a diverse library of 58 distinct fucoidans with multiple contiguous 1,2-cis glycosidic bonds, ranging from disaccharides to dodecasaccharides, using a highly efficient preactivation-based one-pot glycosylation strategy. This library includes compounds with various sulfation patterns (2,3-O-di-, 3,4-O-di-, and 2,3,4-O-tri-sulfation) encompassing nearly all possible fucoidan structures. In vitro anticoagulant assays demonstrate that both molecular size and degree of sulfation play crucial roles in anticoagulant potency. Notably, compounds 29, 30, 37, and 58 significantly prolong human plasma activated partial thromboplastin time (APTT), comparable to the effect of enoxaparin, without affecting prothrombin time (PT) or thrombin time (TT). This selective inhibition of the intrinsic coagulation pathway suggests a reduced risk of bleeding, highlighting the therapeutic potential of these fucoidans as safer anticoagulant agents.

Antimicrobial resistance in Campylobacter spp. focussing on C. jejuni and C. coli - A narrative review

OBJECTIVES

Campylobacter species represent one of the leading causes of human foodborne infections, including gastroenteritis and bloody diarrhoea. Overuse of antibiotics in veterinary, agriculture, and humans has led to an increase in multidrug antimicrobial resistance (AMR). Fluoroquinolones and macrolides resistant Campylobacters are WHO and CDC priority pathogens, with fluoroquinolone resistance doubling in the past 20 years, complicating treatment.

METHODS

Published studies relating to AMR and associated molecular mechanisms in both Campylobacter jejuni (C. jejuni) and C. coli from animals, humans and environment (1981-2024), were retrieved from PubMed and Google Scholar using relevant keywords. In addition, genomic analyses of publicly available C. jejuni and C. coli genomes along with multilocus sequence typing results from the PubMLST database were used to analyse these AMR determinants and their phylogenomic relationships. Review articles were excluded from the analyses.

RESULTS

A total of 429 research papers were reviewed to get insights into multidrug resistance in C. jejuni and C. coli. Fluroquinolone resistance has been predominantly associated with international travel. The gyrA subunits were associated with ecological niches and overall, it is suggestive that C. coli might be the donor. A positive synergism was observed between cmeA gene expression and quinolone resistance. Additionally, the results speculated the possibility of horizontal gene transfers in chromosomal resistance clusters between C. coli and C. jejuni.

CONCLUSIONS

This review indicated significant concern of multidrug resistance in C. jejuni and C. coli. This requires continent-wide surveillance and research for standard practices to achieve effective antimicrobial stewardship.

Applying Computational Protein Design to Engineer Affibodies for Affinity-controlled Delivery of Vascular Endothelial Growth Factor and Platelet-Derived Growth Factor

Vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) play coordinated roles in angiogenesis. However, current biomaterial delivery vehicles for these proteins have a limited ability to precisely control the kinetics of protein release, preventing systematic exploration of their temporal effects. Here, we combined yeast surface display and computational protein design to engineer eight VEGF-specific and PDGF-specific protein binders called affibodies with a broad range of affinities for controlled protein release. Soluble affibodies modulated protein bioactivity as evidenced by changes in VEGF-induced endothelial cell proliferation and luminescent output of a PDGF-responsive cell line. Affibody-conjugated hydrogels enabled tunable protein release over 7 days. VEGF and PDGF released from affibody-conjugated hydrogels exhibited higher bioactivity than proteins released from hydrogels without affibodies, suggesting that these engineered affinity interactions could prolong protein bioactivity. This work underscores the power of computational protein design to enhance biomaterial functionality, creating a platform for tunable protein delivery.

Discovery of SARS-CoV-2 Nsp14-Methyltransferase (MTase) Inhibitors by Harnessing Scaffold-Centric Exploration of the Ultra Large Chemical Space

The global impact of SARS-CoV-2 underscores the need for antiviral treatments beyond vaccines. This study targets Nsp14-MTase, a viral protein essential for replication. Initial quantitative high-throughput screening (qHTS) of ∼15,000 compounds from the selected NCATS in-house libraries identified 135 active hit molecules, reflecting a hit-rate of 1.04%. To enhance the search for promising antiviral agents, we expanded this screening campaign with two rounds of machine learning (ML)-based virtual screening of ∼130,000 compounds. The first iteration yielded 72 active compounds encompassing 27 chemotypes with an IC50 ranging from 1.45 μM to 33.27 μM, increasing the hit-rate 28-fold over the initial qHTS screen. Scaffold clustering of those hits revealed 27 chemotypes. The second iteration added 30 more hits (IC50: 2.18 μM-30.79 μM) across 12 new chemotypes. Initial structure-activity relationship (SAR) exploration around selected chemotypes identified NCGC00606183 (IC50: 0.41 μM) as the most potent hit. Hit-to-lead optimization using scaffold-centric exploration against the ultra large Enamine REAL Space (∼5.6 billion compounds) in HPC clusters identified 78 analogs, with 56 showing potent biochemical activity (IC50: 0.12 μM-18.23 μM) and cellular activity (0.27 μM-23.07 μM) in fully infectious SARS-CoV-2 live virus assays.

CuF2/DTBP-Catalyzed Chan-Lam Coupling of Oxazolidinones with Arylboronic Acid Pinacol Ester: Scope and Application

A new combination of CuF2/DTBP-catalyzed N-arylation of oxazolidinones, amides, amines, and azoles has been explored with arylboronic acid pinacol esters (arylBpin). This methodology has also been applied to the synthesis of oxazolidinone-based marketed drugs, including Rivaroxaban, Linezolid, Sutezolid, and Toloxatone. Mechanistic investigations using various spectroscopic techniques and DFT studies revealed the role of DTBP/MeOH in the catalytic process.

Reductive Breakage of the S-N Bond in S-Amidino Sulfenamides

In this study, reductive breakage of the S-N bond on S-amidino sulfenamides was examined to explore prodrug or covalent drug chemistry for thiourea compounds. Upon thiol treatment, efficient release of varying thioureas could be reached, with Pd catalysis further accelerating this process. Preliminary application to antithyroid drug methylthiouracil confirmed cysteine-triggered release of the parent drug, although further development was hampered by stability issues. These findings highlight the potential of tunable sulfenamide prodrugs to balance release kinetics and stability for thiourea therapeutics.