👤 Matos A

Drug-drug interactions (DDIs) are a significant source of morbidity and adverse drug events (ADEs), particularly in situations of polypharmacy and complex medication regimens. While rules-based software integrated in electronic health records (EHRs) has demonstrated proficiency in identifying DDIs present in medication regimens, large language model (LLM) based identification requires thorough benchmarking and performance evaluation using high-quality datasets for safe use. The purpose of this study was to develop a series of performance benchmarking experiments specifically for LLM performance in identification and management of DDIs using a specifically curated clinician-annotated dataset of clinically-relevant DDIs. Show less

Biomedical research benefits from the rapid growth and diversity of experimentally detected protein-protein interactions (PPIs) by gaining important biological insights. However, increasingly dense PPI networks can be challenging to interpret and apply. The 2025 update of the Integrated Interactions Database (IID) enhances accessibility and utility through several new features. We identify and incorporate network structural components from co-purified protein sets, as well as curated and predicted complexes, enabling users to explore network organization beyond binary interactions. Functional, pathway, and disease associations of these components can be analyzed, enabling interactions to be grouped into higher-order structures with known or provisional biological roles. Users can now filter interactions by five detection types: pairwise, co-purification, colocalization, proximity, and other evidence. To extend the value and information of predicted interactions, we include interaction interface predictions for 53 647 PPIs, generated using the MEGADOCK docking algorithm, adding molecular detail for structural biology and variant impact studies. Finally, we map PPIs to 15 immune cell types and 12 additional normal tissues, offering tissue-specific views of interaction networks increasingly relevant in disease and immunology research. IID 2025 now includes over 1 million experimentally detected human PPIs, representing an 83% increase from the previous release, alongside expanded non-human networks. The portal remains publicly available at https://ophid.utoronto.ca/iid. Show less

The ubiquitously distributed ammonia-oxidizing archaea generate energy from ammonia and build cell mass from inorganic carbon sources, thereby contributing to both the global nitrogen and carbon cycles. However, little is known about the regulation of their predicted core carbon metabolism. A thermodynamic model for Nitrososphaera viennensis was developed to estimate the consumption of inorganic carbon in relation to ammonia consumed for energy and was tested experimentally by growing cells in carbon-limited and excess conditions. A combined proteomic and metabolomic approach to the experimental conditions revealed distinct metabolic adaptation depending on the amount of carbon supplied, either in a catalase or pyruvate background as a reactive oxygen species scavenger. Integration of protein and metabolite dynamics revealed a cellular strategy under carbon limitation to maintain a pool of amino acids and an upregulation of proteins necessary for translation initiation to stay primed for protein synthesis. The combination of modeling and functional genomics fills gaps in the understanding of the central metabolism and its regulation in a chemolithoautotrophic, ammonia-oxidizing archaeon, even in the absence of available genetic tools.IMPORTANCELittle is known about the regulation of carbon metabolism within ammonia-oxidizing archaea (AOA), a widespread clade that plays a critical role in the global nitrogen cycle while also fixing inorganic carbon. To address this missing knowledge, the soil AOA Nitrososphaera viennensis was subjected to various levels of inorganic carbon and analyzed via a systems biology approach to better understand how its core metabolism is regulated. The results demonstrate a strong dependence on the carbon fixation cycle and highlight key connection points between the core metabolic pathways. The analysis additionally revealed tight control on translational processes and elucidated unique cellular responses when the organism was exposed to either exogenous catalase or pyruvate to relieve oxidative stress from reactive oxygen species. The presented data highlight metabolic responses of N. viennensis and provide a better understanding of how the organism, and likely other AOA, respond to various environmental conditions. Show less

Geological structures known as alkaline hydrothermal vents (AHVs) likely displayed dynamic energy characteristics analogous to cellular chemiosmosis and contained iron-oxyhydroxide green rusts in the early Earth. Under specific conditions, those minerals could have acted as non-enzymatic catalysts in the development of early bioenergetic chemiosmotic energy systems while being integrated into the membrane of AHV-produced organic vesicles. Here, we show that the simultaneous addition of two probable AHV components, namely nickel and amino acids, impacts green rust's physico-chemical properties, especially those required for its incorporation in lipid vesicle's membranes, such as decreasing the mineral size to the nanometer scale and increasing its hydrophobicity. These results suggest that such hydrophobic nano green rusts could fit into lipid vesicle membranes and could have functioned as a primitive, inorganic precursor to modern chemiosmotic metalloenzymes, facilitating both electron and proton transport in early life-like systems. Show less

The tumor suppressor protein, p53, which is mutated in half of human tumors, plays a critical role in cellular responses to DNA damage and maintenance of genome stability. Therefore, increasing our understanding of the p53 pathway is essential for improving cancer treatment and diagnosis. Show less

Ferroptosis is a distinct form of regulated cell death characterized by iron-dependent lipid peroxidation, which plays a critical role in the pathogenesis of various diseases, including ischemic tissue injury, infectious diseases, neurodegenerative disorders, and cancer. The regulatory mechanisms underlying ferroptosis involve a complex interplay of multiple subcellular organelles, orchestrating iron homeostasis, lipid metabolism, and the generation of reactive oxygen species (ROS) that drive peroxidation processes, ultimately leading to membrane damage and cell death. Numerous antioxidant systems play pivotal roles in regulating and preventing ferroptosis, among which the recently identified mitochondrial inner membrane enzyme dihydroorotate dehydrogenase (DHODH) represents a novel therapeutic target for ferroptosis intervention. This systematic review comprehensively elucidates several key cellular defense mechanisms against ferroptosis that counteract ROS-driven peroxidation and operate through distinct subcellular localizations. We particularly focus on delineating the molecular mechanisms by which DHODH regulates ferroptosis, with special emphasis on its role in suppressing mitochondrial lipid peroxidation. Furthermore, we systematically evaluate the therapeutic potential of DHODH inhibitors in oncology, virology, and immune-inflammatory disorders. By integrating ferroptosis biology with DHODH-mediated cytoprotective networks, this review aims to provide mechanistic insights and novel therapeutic strategies for cancer and oxidative stress-related disorders. Show less

Modern quantitative image analysis techniques have enabled high-throughput, high-content imaging experiments. Image-based profiling leverages the rich information in images to identify similarities or differences among biological samples, rather than measuring a few features, as in high-content screening. Here, we review a decade of advancements and applications of Cell Painting, a microscopy-based cell-labeling assay aiming to capture a cell's state, introduced in 2013 to optimize and standardize image-based profiling. Cell Painting's ability to capture cellular responses to various perturbations has expanded owing to improvements in the protocol, adaptations for different perturbations, and enhanced methodologies for feature extraction, quality control, and batch-effect correction. Cell Painting is a versatile tool that has been used in various applications, alone or with other -omics data, to decipher the mechanism of action of a compound, its toxicity profile, and other biological effects. Future advances will likely involve computational and experimental techniques, new publicly available datasets, and integration with other high-content data types. Show less

Colorectal cancer (CRC) remains a significant global health challenge, ranking third in incidence and second in mortality among cancers worldwide. This review addresses the complex landscape of CRC, focusing on incidence, mortality trends, preventive strategies, and the evolving therapeutic approaches, particularly highlighting the role of platinum-based drugs like oxaliplatin (OXP). It also underscores the increasing burden of CRC, with factors such as westernized diets, aging populations, and genetic predispositions contributing to its prevalence. Therapeutically, early detection greatly enhances survival rates, emphasizing the importance of regular colonoscopies and stool tests. For advanced CRC, chemotherapy remains pivotal, with OXP as a cornerstone treatment despite its associated chemotherapy-induced peripheral neurotoxicity (CIPN). The review explores innovative strategies to overcome challenges related to chemotherapy, such as drug resistance and side effects, highlighting recent developments in the field, such as Pt(IV) prodrugs and immunotherapeutic approaches to enhance efficacy while minimizing toxicity. Additionally, this manuscript examines experimental models for drug screening, emphasizing the role of murine models and advanced 3D in vitro systems in CRC research. Overall, the review advocates for a comprehensive approach, integrating prevention, early detection, and personalized treatments to alleviate the global burden of CRC. Show less

Mitochondria are essential organelles for many aspects of cellular homeostasis. They play an indispensable role in the development and progression of diseases, particularly cancer which is a major cause of death worldwide. We analyzed the scientific research output on mitochondria and cancer via PubMed and Web of Science over the period 1990-2023. Show less

Ewing sarcoma (EwS) cell line culture largely relies on standard techniques, which do not recapitulate physiological conditions. Here, we report on a feasible and cost-efficient EwS cell culture technique with increased physiological relevance employing an advanced medium composition, reduced fetal calf serum, and spheroidal growth. Improved reflection of the transcriptional activity related to proliferation, hypoxia, and differentiation in EwS patient tumors was detected in EwS cells grown in this refined in vitro condition. Moreover, transcriptional signatures associated with the oncogenic activity of the EwS-specific FET::ETS fusion transcription factors in the refined culture condition were shifted from proliferative toward metabolic gene signatures. The herein-presented EwS cell culture technique with increased physiological relevance provides a broadly applicable approach for enhanced in vitro modeling relevant to advancing EwS research and the validity of experimental results. Show less

The aim of the UniProt Knowledgebase (UniProtKB; https://www.uniprot.org/) is to provide users with a comprehensive, high-quality and freely accessible set of protein sequences annotated with functional information. In this publication, we describe ongoing changes to our production pipeline to limit the sequences available in UniProtKB to high-quality, non-redundant reference proteomes. We continue to manually curate the scientific literature to add the latest functional data and use machine learning techniques. We also encourage community curation to ensure key publications are not missed. We provide an update on the automatic annotation methods used by UniProtKB to predict information for unreviewed entries describing unstudied proteins. Finally, updates to the UniProt website are described, including a new tab linking protein to genomic information. In recognition of its value to the scientific community, the UniProt database has been awarded Global Core Biodata Resource status. Show less

One of the major challenges in precision oncology is the identification of pathogenic, actionable variants and the selection of personalized treatments. We present Onkopus, a variant interpretation framework based on a modular architecture, for interpreting and prioritizing genetic alterations in cancer patients. A multitude of tools and databases are integrated into Onkopus to provide a comprehensive overview about the consequences of a variant, each with its own semantic, including pathogenicity predictions, allele frequency, biochemical and protein features, and therapeutic options. We present the characteristics of variants and personalized therapies in a clear and concise form, supported by interactive plots. To support the interpretation of variants of unknown significance (VUS), we present a protein analysis based on protein structures, which allows variants to be analyzed within the context of the entire protein, thereby serving as a starting point for understanding the underlying causes of variant pathogenicity. Onkopus has the potential to significantly enhance variant interpretation and the selection of actionable variants for identifying new targets, drug screens, drug testing using organoids, or personalized treatments in molecular tumor boards. We provide a free public instance of Onkopus at https://mtb.bioinf.med.uni-goettingen.de/onkopus. Show less

Title: Small upconversion-ruthenium nanohybrids for cancer theranostics. Abstract: Photoresponsive drug delivery systems have great potential for improved cancer therapy. However, most of the currently available drug-delivery nanosystems are relatively large and require light excitation with low tissue penetration. Here, we designed a near infrared responsive drug delivery system by loading [Ru(terpyridine)(dipyridophenazine)(H2O)]2+ (Ru(tpy)DPPZ) in azobenzene-modified mesoporous silica coated NaGdF4:Nd0.01/Yb0.2/Tm0.01 upconversion nanoparticles (azo-mSiO2-UCNPs). Upon 808 nm excitation, the generated ultraviolet and blue upconversion luminescence induced a reversible cis-trans isomerization of azobenzene for on-demand release of Ru(tpy)DPPZ. Imaging of both the UCNPs and Ru(tpy)DPPZ revealed targeted drug delivery to the nucleus of MCF-7 breast cancer cells, inducing DNA damage and concomitant cell destruction. Considering that cell nuclei are the core of cellular transcription and the main site of action for multiple chemotherapeutic drugs, our NIR-excitable and small (10 nm diameter) nanohybrids can potentially become highly versatile tools for targeted cancer theranostics. Show less

To mimic the structural aspects of staurosporine, a potent but unspecific kinase inhibitor, several coordination compounds based on two readily available diimine ligands containing hydrogen bonding donor/acceptor sites (NH-CO fragment) have been designed and synthesized. These complexes are constructed around Ru(II) and Pt(II) metal centers. A total of 9 compounds, named Ru(1)-(5) and Pt(1)-(4), were obtained through straightforward synthetic approaches. The cytotoxicity of the compounds was evaluated on AGS gastric cancer cells (GC) through standard MTT assays. All ruthenium and platinum complexes with low toxicity, i.e.Ru(3), Ru(5), Pt(3) and Pt(4), were docked in the ATP binding pocket of two protein kinases (S6K1 and MST2). The docking scores highlighted a preferred affinity of Ru(5) for the MST2 binding pocket, whereas the platinum compounds are predicted to bind stronger to the S6K1 binding site. Inhibitory activity of the metal complexes on the MST2 and S6K1 signaling pathways was evaluated by analyzing via western blot experiments the phosphorylation state of YAP, a downstream component of the Hippo pathway and the protein expression of S6 and its phosphorylated analogue p-S6. A clear difference of behavior between the Pt(II) and the Ru(II) complexes depending on the type of kinase was observed. Show less

Hypoxia, a hallmark of many solid tumors, is linked to increased cancer aggressiveness, metastasis, and resistance to conventional therapies, leading to poor patient outcomes. This challenges the efficiency of photodynamic therapy (PDT), which relies on the generation of cytotoxic reactive oxygen species (ROS) through the irradiation of a photosensitizer (PS), a process partially dependent on oxygen levels. In this work, we introduce a novel family of potent PSs based on ruthenium(II) polypyridyl complexes with 2,2'-bipyridyl ligands derived from COUPY coumarins, termed COUBPYs. Ru-COUBPY complexes exhibit outstanding in vitro cytotoxicity against CT-26 cancer cells when irradiated with light within the phototherapeutic window, achieving nanomolar potency in both normoxic and hypoxic conditions while remaining nontoxic in the dark, leading to impressive phototoxic indices (>30,000). Their ability to generate both Type I and Type II ROS underpins their exceptional PDT efficiency. The lead compound of this study, SCV49, shows a favorable in vivo pharmacokinetic profile, excellent toxicological tolerability, and potent tumor growth inhibition in mice bearing subcutaneous CT-26 tumors at doses as low as 3 mg/kg upon irradiation with deep-red light (660 nm). These results allow us to propose SCV49 as a strong candidate for further preclinical development, particularly for treating large hypoxic solid tumors. Show less

Title: The role of ancillary ligands on benzodipyridophenazine-based Ru(II)/Ir(III) complexes in dark and light toxicity against TNBC cells. Abstract: In this study, we investigated the impact of ancillary ligands on the anticancer activity of benzodipyridophenazine-based Ru(II) and Ir(III) complexes (Ru1, Ru2, Ir1, and Ir2). These metal complexes displayed three significant absorption bands attributed to the ligand-centered (LC) transitions, ligand-to-ligand charge transfer (LLCT), and metal-to-ligand charge transfer (MLCT). Binding studies of biomolecules were performed with the complexes along with the ligand, and it was found that after binding with Ru(II)/Ir(III), the properties of the ligands were enhanced. In vitro screening revealed that complex [(η5-Cp*)IrIIICl(κ2-N,N-benzo[i]dipyrido[3,2-a:2',3'-c])phenazine] (Ir1) exhibited the highest potency and selectivity (IC50 ∼ 2.14 μM, PI > 13) under yellow light irradiation. The photo-toxicity trend was Ir1 > Ru1 > Ir2 ≫ Ru2, which was found to be directly correlated with the singlet oxygen quantum yield (1O2). Chloro-substituted complexes (Ir1 and Ru1) were effective for hypoxic tumor treatment, particularly Ir1, which could generate high amounts of reactive oxygen species (ROS, type I PDT) in cells under photo irradiation. The high value of fluorescence quantum yield (fφ = 0.26) and significant emission at λ = 571 nm of Ir1 were certainly useful for bio-imaging applications. Colocalisation and DCFDA studies of Ir1 revealed that it can accumulate in the mitochondria, leading to depolarization of the mitochondrial membrane. These studies confirm that the complex Ir1 is a promising candidate for TNBC treatment in hypoxic tumors, with efficacy comparable to the current PDT drug Photofrin. Show less

To overcome the undesirable side effects and acquired resistance associated with platinum-based chemotherapeutics, scientists are searching for alternative strategies involving novel metal-based compounds with improved pharmacological properties. Ruthenium complexes have emerged as prospective candidates to combat side effects and improve the selectivity of anticancer agents. In this work, a benzimidazole-based chelating ligand, HL (4-(1H-naphth[2,3-d]imidazol-2-yl)-1,3-benzenediol) with O and N donor atoms, was synthesized and used for complexation with ruthenium to obtain three Ru(II) arene complexes represented by [Ru(η⁶-p-cym)(L)Cl], [Ru(η⁶-p-cym)(L)(PPh₃)]⁺ and [Ru(η⁶-p-cym)(L)(PTA)]⁺ (where p-cym = p-cymene, PPh₃ = triphenylphosphine and PTA = 1,3,5-triaza-7-phosphaadamantane). The synthesized complexes were characterized using spectroscopic techniques. UV-Vis absorption spectroscopy and LC-MS were used to study the stability of the complexes in biological medium. Their lipophilicity was studied by calculating the partition coefficient in n-octanol and water. The complexes showed significant binding with biomolecules like albumin proteins and nucleic acids. All the complexes were found to be cytotoxic, with complex [Ru(η⁶-p-cym)(L)PPh₃]PF₆ exhibiting the highest anticancer activity. The mechanism of anticancer activity was attributed to the ability of the complexes to induce apoptosis and generate reactive oxygen species (ROS). The complexes also exhibited antimetastatic properties. Furthermore, complex [Ru(η⁶-p-cym)(L)PPh₃]PF₆ was loaded onto amine-functionalized mesoporous silica nanoparticles which led to an increase in its cytotoxic activity. Show less

In recent years, photodynamic therapy (PDT) has emerged as a promising alternative to classical chemotherapy for treating cancer. PDT is based on a nontoxic prodrug called photosensitizer (PS) activated by light at the desired location. Upon irradiation, the PS reacts with the oxygen present in the tumor, producing cytotoxic reactive oxygen species (ROS). Compounds with highly conjugated π-bond systems, such as porphyrins and chlorins, have proven to be excellent light scavengers, and introducing a metal atom in their structure improved the generation of ROS. In this work, a series of tetrapyrrole-ruthenium(II) complexes derived from protoporphyrin IX and the commercial drug verteporfin were designed as photosensitizers for PDT. The complexes were almost nontoxic on human gastric cancer cells under dark conditions, revealing remarkable cytotoxicity upon irradiation with light. The ruthenium atom in the central cavity of the chlorin ligand allowed combined mechanisms in photodynamic therapy, as both singlet oxygen and superoxide radicals were detected. Additionally, one complex produced large amounts of singlet oxygen under hypoxic conditions. Biological assays demonstrated that the ruthenium derivatives caused cell death through a caspase 3 mediated apoptotic pathway and via CHOP, an endoplasmic reticulum stress-inducible transcription factor involved in apoptosis and growth arrest. Show less

Background/objectives

Breast cancer (BC) remains one of the most prevalent and deadly cancers worldwide, with limited access to advanced treatments in developing regions. There is a critical need for novel therapies with unique mechanisms of action, especially to overcome resistance to conventional platinum-based drugs. This study investigates the anticancer potential of the ruthenium complex Bis(quinolin-8-olato)bis(triphenylphosphine)ruthenium(II) (Ru(quin)₂) in ER-positive (T47D) and triple-negative (MDA-MB-231) BC cell lines.

Results

Ru(quin)₂ demonstrated dose-dependent cytotoxicity, with IC50 values of 48.3 μM in T47D cells and 45.5 μM in MDA-MB-231 cells. Its cytotoxic effects are primarily driven by apoptosis, as shown by increased BAX expression, enhanced caspase-3 activity, reduced Aurora B kinase levels, and elevated histone release. Ru(quin)₂ also induced autophagy, evidenced by LC3-I to LC3-II conversion and reduced SQSTM1, partially mediated through MAPK signaling. Furthermore, Ru(quin)₂ induced G0/G1 cell cycle arrest by downregulating cyclin D1, CDK4, and CDK6, alongside upregulation of the CDK inhibitor p21.

Conclusions

Ru(quin)₂ emerges as a potent candidate for BC treatment, with multiple mechanisms of action involving apoptosis, autophagy, and cell cycle arrest. Further studies are warranted to elucidate its detailed molecular mechanisms and evaluate its therapeutic potential in vivo, moving toward clinical applications for both ER-positive and triple-negative BC management. Show less

The six mononuclear Schiff's base Ru(III) complexes viz., [Ru(BZP)(LA)₂].2NO₃ (MRA), [Ru(BZP)(LB)₂].2NO₃ (MRB), [Ru(BZP))(LC)₂].2NO₃ (MRC), [Ru(BZP))(LD)₂].2NO₃ (MRD), [Ru(BZP)(LE)₂].2NO₃ (MRE) and [Ru(BZP)(LF)₂].2NO₃ (MRF), were synthesized using of (BZP=2,6-bis(2-benzimidazolyl)pyridine and p-sub-benzylthiosemicarbazones (BTS) [(Sub=4-NO₂ (LA), 4-N(CH₃)₂ (LB), 4-Cl (LC), 4-OCH₃ (LD), 4-OCH₂Ph (LE), and 4-OH (LF)] as an ancillary ligands. The thiosemicarbazones ligands (LA-LF) were obtained by the condensation of p-substituted benzaldehyde and thiosemicarbazide. These complexes were characterized by elemental analysis, IR, ESR, ESI-MS, electronic absorption spectroscopy. The geometry was optimized by theoretical calculation using DFT and structure reveals that MRA-MRF adopt octahedral geometry. Further, the complexes were examined for anti-cancer against Leukemia cancer cell line K562 and shown significant responses to these cells. Moreover, DNA binding studies were conducted with all complexes MRA-MRF and the binding constant (K_b) were found i.e., 1.10×10⁴, 1.54×10⁴, 2.87×10⁴, 1.67×10⁴, 1.98×10⁴ and 1.59×10⁴, respectively. It was found that DNA binds in intercalation mode which is also validated by the docking studies. Show less

We developed a novel red light activable hetero-bimetallic [Fe(III)-Ru(II)] complex by combining hydroxyl radical-generating Fe(III)-catecholate as a type I PDT agent and the singlet oxygen generating Ru(II)-paracymene complex as a type II PDT agent and it potentially functions as a dual-modality PDT tool for enhanced phototherapeutic applications. 2-Amino-3-(3,4-dihydroxyphenyl)-N-(1,10-phenanthrolin-5-yl)propenamide (L2) acted as a bridging linker. The single-pot synthesis of the hetero-bimetallic [Fe(III)-Ru(II)] complex was carried out through acid-amine coupling. Various photophysical assays confirmed the photo-activated production of (˙OH) radicals and (¹O₂) oxygen generation upon activation of the [Fe(III)-Ru(II)] complex with red light (600-720 nm, 30 J cm^-2), which resulted in enhanced cytotoxicity with a photo-index of ∼45. The complex, [Fe(III)-Ru(II)], potentially bonded to the DNA through the ruthenium moiety was responsible for minimal dark toxicity. The cytotoxic potential of the complex under red light was a result of the photo-induced accumulation of reactive oxygen species through both type I and type II photodynamic therapy (PDT) mechanisms in A549 and HeLa cells, while non-cancerous HPL1D cells remained unaffected. We probed the caspase 3/7-dependent apoptosis of the complex, [Fe(III)-Ru(II)], in vitro. Overall, the hetero-bimetallic [Fe(III)-Ru(II)] complex is an ideal example of a red light activable dual-modality next-generation PDT tool for phototherapeutic anticancer therapy. Show less

Two new Ru(II) complexes, mononuclear [RuCl₂(η⁶-p-cymene)(3,4-dmph-κN)] (1) and the binuclear complex [{RuCl(η⁶-p-cymene)}₂(μ-Cl)(μ-3,4-dmph-κ²N,N')]Cl (2; 3,4-dmph = 3,4-dimethylphenylhydrazine), are synthesized and experimentally and theoretically structurally characterized utilizing ¹H and ¹³C NMR and FTIR spectroscopy, as well as DFT calculations. Degradation product of 2, thus ([{RuCl(η⁶-p-cymene)}₂(μ-Cl)(μ-3,4-dmph-κ²N,N')][RuCl₃(η⁶-p-cymene)] (2b) was characterized with SC-XRD. In the crystals of 2b, the cationic and anionic parts interact through N-H^...Cl hydrogen bridges. The spectrofluorimetric measurements proved the spontaneity of the binding processes of both complexes and HSA. Spin probing EPR measurements implied that 1 and 2 decreased the amount of bound 16-doxylstearate and implicated their potential to bind to HSA more strongly than the spin probe. The cytotoxicity assessment of both complexes against the MDA-MB-231 and MIA PaCa-2 cancer cell lines demonstrated a clear dose-dependent decrease in cell viability and no effect on healthy HS-5 cells. Determination of the malondialdehyde and protein carbonyl concentrations indicated that new complexes could offer protective antioxidant benefits in specific cancer contexts. Gel electrophoresis measurements showed the reduction in MMP9 activity and indicated the potential of 1 in limiting the cancer cells' invasion. The annexin V/PI apoptotic assay results showed that 1 and 2 exhibit different selectivity towards MIA PaCa-2 and MDA-MB-231 cancer cells. A comparative molecular docking analysis of protein binding, specifically targeting acetylcholinesterase (ACHE), matrix metalloproteinase-9 (MMP-9), and human serum albumin (HSA), demonstrated distinct binding interactions for each complex. Show less

Intracellular imaging of anticancer metallodrugs often relies on prelabeling with organic fluorophores, which significantly affects their physicochemical properties and intracellular distribution. On the other hand, the reported postlabeling strategies based on click-chemistry reactions require cell fixation and permeabilization. Here, this study presents a postlabeling approach based on the catalyst-free, inverse electron-demand Diels-Alder reaction (iEDDA) between a strained fluorescein-tagged bicyclononyne derivative (BCN-FAM) and half-sandwich Ir(III) complexes containing bidentate ligands comprising a tetrazine (Tz-R,R') entity. Five half-sandwich Ir(III) complexes with formula [Cp*Ir(Tz-R,R')Cl]^0/+ have been synthesized and fully characterized, including the X-ray crystal structures of three of the five derivatives. Investigations of their stability and their reactivity in aqueous solution and in a model iEDDA reaction reveal the strong influence of the tetrazine ligand structure on the chemical properties of the corresponding complexes. A highly cytotoxic metallodrug candidate (Ir-C,N_Ph,Me) is identified from biological studies, and chemical reactivity studies disclose an unusual preference for binding of methionine over cysteine. Postlabeling of Ir-C,N_Ph,Me in live HeLa cells highlights its preferential accumulation within the nucleus, suggesting its retention through covalent modifications of nuclear proteins in good agreement with other half-sandwich iridium(III) complexes. Show less

While molecular isomers exhibit nearly identical compositions, their spatial arrangement often dictates distinct physicochemical properties. We present a regioisomer engineering strategy to construct two iridium(III) complexes (Ir1 and Ir2) through precise positioning of triphenylamine electron donors relative to the metal chelation core. Compared to Ir1, Ir2 features strategically displaced donors that create a contracted bandgap, reduced oxidation potential, and amplified spin-orbit coupling (SOC). These electronic modifications synergistically enable Ir2 to achieve superior type I photodynamic activity and thus generate O₂^•- and •OH radicals after 633 nm irradiation even under hypoxic conditions. The sustained reactive oxygen species (ROS) production induces potent immunogenic cell death (ICD), ultimately stimulating dendritic cell maturation and antitumor immunity. This regioisomeric design paradigm establishes a molecular blueprint for oxygen-tolerant photosensitizers, addressing the critical challenge of hypoxia in photoimmunotherapy applications. Show less

A novel bioorganometallic PNA conjugate (Ir-PNA) was synthesized by covalently bonding a model PNA tetramer to a luminescent bis-cyclometalated Ir(III) complex that acted as a photosensitizer under light irradiation to generate singlet oxygen (¹O₂). The conjugate was prepared using an Ir complex bearing the 1,10-phenanthroline ligand functionalized with either a free primary amine (Ir-NH₂) or a carboxyl group (Ir-COOH) for the conjugation to PNA. The photophysical studies on the Ir-COOH and the Ir-PNA demonstrated that the luminescent properties were maintained after the conjugation of the Ir fragment to PNA. Furthermore, the abilities to produce ¹O₂ of Ir-COOH and Ir-PNA were confirmed in a cuvette under visible light irradiation employing 1,5-dihydroxynaphthalene as a reporter, and the measured singlet oxygen quantum yield (Φ_Δ) supported the Ir-PNA conjugate efficacy as a photosensitizer (Φ_Δ = 0.54). Two-photon absorption microscopy on HeLa cells revealed that Ir-PNA localized in both the cytosol and nucleus, suggesting its potential as an intracellular carrier for PNA. Cytotoxicity assays by MTT tests showed that Ir-PNA was nontoxic in the absence of light, but induced cell death (EC₅₀ = 18 μM) after UV irradiation. Overall, the Ir-PNA conjugate represents a promising system for the intracellular delivery of the PNA and its application in PDT. Show less

Three novel cyclometalated Ir(III) complexes, Ir1-Ir3, were synthesized and thoroughly characterized. These complexes exhibited absorption in the 350-480 nm range, making them suitable candidates for visible-light-mediated photocatalytic cancer therapy. Under visible-light exposure in a DMSO:PBS (1:99 v/v) solvent system, all three photocatalysts demonstrated high efficiency in facilitating NADH oxidation, attaining turnover frequencies (TOFs) in the range of 499-698 h⁻¹, exceeding the performance of most of the previously reported Ir(III)-based photocatalysts. Mechanistic studies verified the involvement of type I and type II pathways for ROS generation. Cytotoxicity studies highlighted significant photocytotoxic effects of Ir1-Ir3 in human lung adenocarcinoma cells (A549), with Ir3 emerging as the most potent under light exposure. Additionally, the negligible dark and light cytotoxicity of Ir3 against human embryonic kidney cells (HEK-293) demonstrated the safety profile of Ir3. Furthermore, the mechanistic studies in A549 cells revealed that Ir3 promoted mitochondrial membrane depolarization and activated caspase-3/7-dependent apoptotic pathways through light-triggered ROS generation and NADH oxidation. These findings highlight Ir3 as a potent dual-action cancer phototherapeutic, capable of synergistically inducing type-I and type-II anticancer activity, and efficient NADH photo-oxidation. This work presents a promising platform for developing multifunctional photocatalytic agents in cancer therapy. Show less

Title: Monomer Versus Dimer of Cationic Ir(III) Complexes for Photodynamic Therapy by Two-Photon Activation: A Comparative Study. Abstract: Iridium(III) complexes have been recognized as promising candidates for two-photon sensitized photodynamic therapy (PDT). In this context, we report on the study of two complexes: a monomer (IrL1) and a dimer (Ir2L2). Both complexes possess 2-phenylpyridine cyclometallating ligands and a pyridylbenzimidazole derivative as an ancillary ligand. In the dimer, the two Ir(III) centers are connected by a non-conjugated bridged bis(pyridylbenzimidazole). We compare the photophysical properties of these complexes. Both display phosphorescent emission in the orange-red part of the visible spectrum, with emissions centered at 610 nm for IrL1 and 625 nm for Ir2L2, both exhibiting quantum yields of ∼24%. However, Ir2L2 proves to be much brighter than the monomer, making the dimer four times brighter than IrL1. This trend is consistent under two-photon excitation (TPE), and the singlet oxygen generation quantum yields, with the dimer displaying a figure of merit (σTPA × ΦΔ) of 40, compared to only 5 for the monomer. Both complexes generate intracellular ROS and exhibit strong phototoxicity upon blue light activation (λ = 420 nm), achieving submicromolar IC50 values in HT29 and A549 cell lines after 24 h of incubation. Moreover, with TPE (λ = 800 nm), both complexes also generate intracellular ROS and induce cancer cell death. Show less

Drug-target interaction (DTI) prediction is a relevant but challenging task in the drug repurposing field. In-silico approaches have drawn particular attention as they can reduce associated costs and time commitment of traditional methodologies. Yet, current state-of-the-art methods present several limitations: existing DTI prediction approaches are computationally expensive, thereby hindering the ability to use large networks and exploit available datasets and, the generalization to unseen datasets of DTI prediction methods remains unexplored, which could potentially improve the development processes of DTI inferring approaches in terms of accuracy and robustness. Show less

The co-administration of drugs known to interact greatly impacts morbidity, mortality, and health economics. This study aims to examine the drug-drug interaction (DDI) phenomenon with a large-scale longitudinal analysis of age and gender differences found in drug administration data from three distinct healthcare systems. Show less

Brain cancer is regarded as one of the most life-threatening forms of cancer worldwide. Oxidative stress acts to derange normal brain homeostasis, thus is involved in carcinogenesis in brain. The Nrf2/Keap1/ARE pathway is an important signaling cascade responsible for the maintenance of redox homeostasis, and regulation of anti-inflammatory and anticancer activities by multiple downstream pathways. Interestingly, Nrf2 plays a somewhat, contradictory role in cancers, including brain cancer. Nrf2 has traditionally been regarded as a tumor suppressor since its cytoprotective functions are considered to be the principle cellular defense mechanism against exogenous and endogenous insults, such as xenobiotics and oxidative stress. However, hyperactivation of the Nrf2 pathway supports the survival of normal as well as malignant cells, protecting them against oxidative stress, and therapeutic agents. Plants possess a pool of secondary metabolites with potential chemotherapeutic/chemopreventive actions. Modulation of Nrf2/ARE and downstream activities in a Keap1-dependant manner, with the aid of plant-derived secondary metabolites exhibits promise in the management of brain tumors. Current article highlights the effects of Nrf2/Keap1/ARE cascade on brain tumors, and the potential role of secondary metabolites regarding the management of the same. Show less