Challenges In Drug Development Research Articles

Substance Delivery across the Blood-Brain Barrier or the Blood-Retinal Barrier Using Organic Cation Transporter Novel Type 2 (OCTN2)

The membrane impermeability of a drug poses a significant challenge in drug research and development, preventing effective drug delivery to the target site. Specifically, the blood-brain barrier (BBB) presents a formidable obstacle to the delivery of drugs targeting the central nervous system (CNS) into the brain, whereas the blood-retinal barrier (BRB) presents a tremendous obstacle to the delivery of drugs targeting the ocular diseases into the eyes. The development of drugs for Alzheimer’s or Parkinson’s disease targeting the CNS and for diabetic retinopathy and age-related macular degeneration targeting the eyes remains an unmet medical need for patients. Transporters play a crucial physiological role in maintaining homeostasis in metabolic organs. Various types of solute carrier (SLC) transporters are expressed in the capillary endothelial cells of the BBB, facilitating the delivery of nutrients from the blood flow to the brain. Therefore, carrier-mediated transport across the BBB can be achieved using SLC transporters present in capillary endothelial cells. It is well-known that CNS drugs typically incorporate N-containing groups, indicating that cation transporters facilitate their transport into the brain. In fact, carrier-mediated transport across the BBB can be accomplished using glucose transporter type 1 (Glut1) as a glucose transporter, L-type amino acid transporter 1 (LAT1) as a large neutral amino acid transporter, and H+/cation antiporter as a cation transporter. Surprisingly, although organic cation transporter novel type 2 (OCTN2) is expressed in the capillary endothelial cells, there has been limited investigation into OCTN2-mediated substance delivery into the brain across the BBB. Furthermore, it is suggested that OCTN2 is expressed at the BRB. In this prospective review, I present the advantages and possibilities of substance delivery into the brain across the BBB or into the eyes across the BRB, mediated by OCTN2 via carrier-mediated transport or receptor-mediated transcytosis.

Mapping the Single-Cell Differentiation Landscape of Osteosarcoma.

The genetic intratumoral heterogeneity observed in human osteosarcomas poses challenges for drug development and the study of cell fate, plasticity, and differentiation, which are processes linked to tumor grade, cell metastasis, and survival. To pinpoint errors in osteosarcoma differentiation, we transcriptionally profiled 31,527 cells from a tissue-engineered model that directs mesenchymal stem cells toward adipogenic and osteoblastic fates. Incorporating preexisting chondrocyte data, we applied trajectory analysis and non-negative matrix factorization to generate the first human mesenchymal differentiation atlas. This "roadmap" served as a reference to delineate the cellular composition of morphologically complex osteosarcoma tumors and quantify each cell's lineage commitment. Projecting a bulk RNA-sequencing osteosarcoma dataset onto this roadmap unveiled a correlation between a stem-like transcriptomic phenotype and poorer survival outcomes. Our study quantifies osteosarcoma differentiation and lineage, a prerequisite to better understanding lineage-specific differentiation bottlenecks that might someday be targeted therapeutically.

A hybrid quantum computing pipeline for real world drug discovery

Quantum computing, with its superior computational capabilities compared to classical approaches, holds the potential to revolutionize numerous scientific domains, including pharmaceuticals. However, the application of quantum computing for drug discovery has primarily been limited to proof-of-concept studies, which often fail to capture the intricacies of real-world drug development challenges. In this study, we diverge from conventional investigations by developing a hybrid quantum computing pipeline tailored to address genuine drug design problems. Our approach underscores the application of quantum computation in drug discovery and propels it towards more scalable system. We specifically construct our versatile quantum computing pipeline to address two critical tasks in drug discovery: the precise determination of Gibbs free energy profiles for prodrug activation involving covalent bond cleavage, and the accurate simulation of covalent bond interactions. This work serves as a pioneering effort in benchmarking quantum computing against veritable scenarios encountered in drug design, especially the covalent bonding issue present in both of the case studies, thereby transitioning from theoretical models to tangible applications. Our results demonstrate the potential of a quantum computing pipeline for integration into real world drug design workflows.

From Plan to Pivot: How Model-Informed Drug Development Shaped the Dose Strategy of the Zibotentan/Dapagliflozin ZENITH Trials.

Getting the dose right is a key challenge in drug development; model-informed drug development (MIDD) provides powerful tools to shape dose strategies and inform decision making. In this tutorial, the case study of the ZENITH trials showcases how a set of clinical pharmacology and MIDD approaches informed an impactful dose strategy. The endothelin A receptor antagonist zibotentan, combined with the sodium-glucose co-transporter-2 inhibitor dapagliflozin, has yielded a robust and significant albuminuria reduction in the Phase IIb trial ZENITH-CKD and is being investigated for reduction of kidney function decline in a high-risk chronic kidney disease population in the Phase III trial ZENITH High Proteinuria. Endothelin antagonist treatment has, until now, been limited by the class effect fluid retention. ZENITH-CKD investigated a wide range of zibotentan doses based on pharmacokinetics in renal impairment, competitor-data exposure-response modeling, and clinical trial simulations. Recruitment delays reduced interim analysis data availability; here, supportive dose-response modeling recovered decision-making confidence. At trial completion, the low-dose arm enabled Phase III dose selection between Phase IIb doses. Dose-response modeling of efficacy and Kaplan-Meier analyses of tolerability identified a kidney-function-based low-dose strategy of 0.25 or 0.75 mg zibotentan (with 10 mg dapagliflozin) to balance benefit/risk in ZENITH High Proteinuria. The applied clinical pharmacology and MIDD principles enabled successful Phase IIb dose finding, rationalized and built confidence in the innovative Phase III dosing strategy and identified a potential therapeutic window for zibotentan/dapagliflozin, providing the opportunity for a significant improvement in the treatment of chronic kidney disease with high proteinuria.

Membrane Fusion-Mediated Loading of Therapeutic siRNA into Exosome for Tissue-Specific Application.

Tissue-specific delivery of oligonucleotide therapeutics beyond the liver remains a key challenge in nucleic acid drug development. To address this issue, exploiting exosomes as a novel carrier has emerged as a promising approach for efficient nucleic acid drug delivery. However, current exosome-based delivery systems still face multiple hurdles in their clinical applications. Herein, we present a strategy for constructing a hybrid exosome vehicle (HEV) through a DNA zipper-mediated membrane fusion approach for tissue-specific siRNA delivery. As a proof-of-concept, we successfully fused a liposome encapsulating anti-NFKBIZ siRNAs with corneal epithelium cell (CEC)-derived exosomes to form a HEV construct for the treatment of dry eye disease (DED). With homing characteristics inherited from exosomes, our siRNA-bearing HEV can target its parent cells and efficiently deliver the siRNA payloads to the cornea. Subsequently, the NFKBIZ gene silencing significantly reduces pro-inflammatory cytokine secretions from the ocular surface, reshapes its inflammatory microenvironment, and ultimately achieves an excellent therapeutic outcome in a DED mouse model. As a versatile platform, our hybrid exosome with targeting capability and designed therapeutic siRNAs may hold great potential in various disease treatments. This article is protected by copyright. All rights reserved.

Critical Appraisal and Future Challenges of Artificial Intelligence and Anticancer Drug Development.

The conventional rules for anti-cancer drug development are no longer sufficient given the relatively limited number of patients available for therapeutic trials. It is thus a real challenge to better design trials in the context of new drug approval for anti-cancer treatment. Artificial intelligence (AI)-based in silico trials can incorporate far fewer but more informative patients and could be conducted faster and at a lower cost. AI can be integrated into in silico clinical trials to improve data analysis, modeling and simulation, personalized medicine approaches, trial design optimization, and virtual patient generation. Health authorities are encouraged to thoroughly review the rules for setting up clinical trials, incorporating AI and in silico methodology once they have been appropriately validated. This article also aims to highlight the limits and challenges related to AI and machine learning.

Targeting of nanoparticles to the cerebral vasculature after traumatic brain injury.

Traumatic brain injury has faced numerous challenges in drug development, primarily due to the difficulty of effectively delivering drugs to the brain. However, there is a potential solution in targeted drug delivery methods involving antibody-drug conjugates or nanocarriers conjugated with targeting antibodies. Following a TBI, the blood-brain barrier (BBB) becomes permeable, which can last for years and allow the leakage of harmful plasma proteins. Consequently, an appealing approach for TBI treatment involves using drug delivery systems that utilize targeting antibodies and nanocarriers to help restore BBB integrity. In our investigation of this strategy, we examined the efficacy of free antibodies and nanocarriers targeting a specific endothelial surface marker called vascular cell adhesion molecule-1 (VCAM-1), which is known to be upregulated during inflammation. In a mouse model of TBI utilizing central fluid percussion injury, free VCAM-1 antibody did not demonstrate superior targeting when comparing sham vs. TBI brain. However, the administration of VCAM-1-targeted nanocarriers (liposomes) exhibited a 10-fold higher targeting specificity in TBI brain than in sham control. Flow cytometry and confocal microscopy analysis confirmed that VCAM-1 liposomes were primarily taken up by brain endothelial cells post-TBI. Consequently, VCAM-1 liposomes represent a promising platform for the targeted delivery of therapeutics to the brain following traumatic brain injury.

Oropouche virus – The “Newest” invisible public enemy?

This perspective underscores the rising challenge posed by emerging diseases against the backdrop of modern advancements in global public health understanding. It particularly highlights the emergence of the Oropouche virus (OROV) as a significant global threat, detailing its transmission dynamics, symptoms, and epidemiological impact, with a focus on its historical and current manifestations. It further delves into the molecular aspects of OROV, elucidating its unique characteristics, lack of structural similarity with other arboviruses, and the limited progress in medicinal chemistry research. Still, it highlights notable studies on potential antiviral agents and the challenges in drug development, emphasizing the need for innovative approaches such as structure-based drug design (SBDD) and drug repurposing. Finally, it concludes with a call to action, urging increased attention and research focus on OROV to prevent potential future pandemics fueled by viral mutations.

Tuning Peptide-Based Nanofibers for Achieving Selective Doxorubicin Delivery in Triple-Negative Breast Cancer.

The design of delivery tools that efficiently transport drugs into cells remains a major challenge in drug development for most pathological conditions. Triple-negative breast cancer (TNBC) is a very aggressive subtype of breast cancer with poor prognosis and limited effective therapeutic options. In TNBC treatment, chemotherapy remains the milestone, and doxorubicin (Dox) represents the first-line systemic treatment; however, its non-selective distribution causes a cascade of side effects. To address these problems, we developed a delivery platform based on the self-assembly of amphiphilic peptides carrying several moieties on their surfaces, aimed at targeting, enhancing penetration, and therapy. Through a single-step self-assembly process, we used amphiphilic peptides to obtain nanofibers decorated on their surfaces with the selected moieties. The surface of the nanofiber was decorated with a cell-penetrating peptide (gH625), an EGFR-targeting peptide (P22), and Dox bound to the cleavage sequence selectively recognized and cleaved by MMP-9 to obtain on-demand drug release. Detailed physicochemical and cellular analyses were performed. The obtained nanofiber (NF-Dox) had a length of 250 nm and a diameter of 10 nm, and it was stable under dilution, ionic strength, and different pH environments. The biological results showed that the presence of gH625 favored the complete internalization of NF-Dox after 1h in MDA-MB 231 cells, mainly through a translocation mechanism. Interestingly, we observed the absence of toxicity of the carrier (NF) on both healthy cells such as HaCaT and TNBC cancer lines, while a similar antiproliferative effect was observed on TNBC cells after the treatment with the free-Dox at 50 µM and NF-Dox carrying 7.5 µM of Dox. We envision that this platform is extremely versatile and can be used to efficiently carry and deliver diverse moieties. The knowledge acquired from this study will provide important guidelines for applications in basic research and biomedicine.

A modular, open-label, phase I/IIa study to evaluate the safety, tolerability, pharmacokinetics (PKs) and anti-tumour activity of a first-in-class (FIC) specific dUTPase inhibitor CV6-168 combined with anti-cancer treatments in patients (pts) with advanced malignancies.

TPS3170 Background: CV6-168 is a FIC DNA uracilation agent targeting the enzyme dUTPase with high specificity. CV6-168 induces misincorporation of uracil into DNA when combined with thymidylate synthase (TS) inhibitors resulting in significantly increased DNA damage and lethality in cancer cells and activation of immune stimulatory mechanisms. CV6-168 does not inhibit dihydropyrimidine dehydrogenase, the rate-limiting enzyme responsible for 5-FU catabolism avoiding fluoropyrimidine drug-drug interactions and complex dose modifications. This is a first-in-human, modular study initially investigating PK and safety of CV6-168 with bolus/infusional 5-fluorouracil (5-FU) and folinic acid (FA). Methods: Primary objective: characterise safety and tolerability of CV6-168 with 5-FU and FA. Secondary objectives: establish PK profile of CV6-168 and 5-FU alone and in combination and evaluate anti-tumour activity of the combination. Exploratory objectives: investigate multiple surrogate, tumour and circulating pharmacodynamic assays related to mechanism of action and predictive biomarkers for CV6-168 and 5-FU. Each module of this study investigates a different hypothesis, driven by emerging data. Module 1, investigating CV6-168/5-FU/FA, consists of Part A (dose escalation in up to 51 pts) where the maximum tolerated/feasible dose will be identified to guide dose optimisation; Part B, proof of concept [PoC] expansions and identification of the recommended Phase 2 dose/schedule; and optional Parts C (dose optimisation cohorts) and D (basket cohort expansions). Part A is a “3 + 3” dose escalation design in pts with incurable advanced solid tumours and Part B expansions, powered to compare response rates to historical data, will include 3 cohorts of different tumour types. Part C is a randomised comparison of 2 doses/schedules to be selected based on Part A and B data, with pt populations selected based on emerging data. Further Modules may explore: Combination of CV6-168/5-FU/FA with a PD-(L)1 inhibitor; Combinations with other standard of care treatments; Food effects on CV6-168 bioavailability; and Different CV6-168 formulations. This trial design 1) Allows one protocol responsive to emerging data for a compound with multiple hypotheses, supporting studies in multiple combinations, reducing time from emerging data to ‘first subject in study" compared with multiple individual studies; 2) Has the potential to reduce the number of pts unnecessarily exposed to a novel agent; and 3) Allows investigators to pre-empt emerging data and changes to the treatment landscape. These challenges in oncology drug development emphasize the need for flexible designs as the landscape of drug development continually evolves. Clinical trial information: ISRCTN12434145.

Modeling doxorubicin-induced cardiotoxicity with human myocardial tissue slices: insights on genetic susceptibility and cardioprotection

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): PSIDER and HARVEY (ZonMW) Introduction Cardiotoxicity poses a significant challenge in drug development, often leading to the withdrawal of approved drugs. To address this issue, there is a critical need for improved models to predict cardiac adverse effects. In line with the imperative for animal-free preclinical testing, this study aimed to develop a novel model using human myocardial tissue slices to get a deeper understanding and potential prevention of doxorubicin-Induced cardiotoxicity. Methods Human myocardial tissue slices of 300 μm thick were derived from end-stage heart failure patients explanted hearts, including those harbouring likely or pathogenic cardiovascular mutations (class 4 and 5) (N=3) and non-genetic cardiovascular etiology (N=3). Myocardial tissue slices were cultured under physiological mechanical and electrical conditions. Slices were exposed to doxorubicin (1 µM) over a 10-day culture period, and their responses were compared to DMSO-vehicle controls, by recording contractile force and Ca2+ transients. Additionally, a subset of slices was treated with a cardioprotective agent, dexrazoxane (100 µM), 1 day prior to and during doxorubicin exposure to assess potential cardioprotection. Results Doxorubicin-exposed slices with a pathogenic mutation exhibited reduced mechanical force, increased threshold potential, and impaired ability to follow pacing at higher frequencies. Additionally, aberrations in calcium handling, manifested as arrhythmia-like disconnection of muscle fibers, were notably observed in these slices. Instead, slices from patients without pathogenic mutations showed minimal cardiotoxicity when exposed to doxorubicin. Encouragingly, pretreatment with dexrazoxane demonstrated a protective effect against doxorubicin-induced cardiotoxicity in the genetically susceptible group. Our functional findings corroborated our structural data, highlighting the breakdown of sarcomere structure and cell-cell connections and increased DNA damage, particularly in patients harbouring a genetic cardiovascular mutation. Conclusion In summary, human myocardial tissue slices faithfully recapitulate doxorubicin-induced cardiotoxicity. Importantly, our data suggests the utility of employing genetic testing for known cardiovascular mutations as a valuable step before initiating doxorubicin treatment. Additionally, we demonstrate for the first time the in vitro cardioprotective potential of dexrazoxane in a human tissue model. These findings pave the way for using ex vivo myocardial tissue slices to evaluate cardiotoxicity and their value as a powerful tool for evaluating the efficacy and delivery approaches.

Site Identification and Next Choice Protocol for Hit-to-Lead Optimization.

Time efficiency and cost savings are major challenges in drug discovery and development. In this process, the hit-to-lead stage is expected to improve efficiency because it primarily exploits the trial-and-error approach of medicinal chemists. This study proposes a site identification and next choice (SINCHO) protocol to improve the hit-to-lead efficiency. This protocol selects an anchor atom and growth site pair, which is desirable for a hit-to-lead strategy starting from a 3D complex structure. We developed and fine-tuned the protocol using a training data set and assessed it using a test data set of the preceding hit-to-lead strategy. The protocol was tested for experimentally determined structures and molecular dynamics (MD) ensembles. The protocol had a high prediction accuracy for applying MD ensembles, owing to the consideration of protein flexibility. The SINCHO protocol enables medicinal chemists to visualize and modify functional groups in a hit-to-lead manner.

Investigation of Hydrocolloid Plant Polysaccharides as Potential Candidates to Mimic the Functions of MUC5B in Saliva

The successful substitution of complex physiological fluids, such as human saliva, remains a major challenge in drug development. Although there are a large number of saliva substitutes on the market, their efficacy is often inadequate due to short residence time in the mouth, unpleasant mouthfeel, or insufficient protection of the teeth. Therefore, systems need to be identified that mimic the functions of saliva, in particular the salivary mucin MUC5B and the unique physiological properties of saliva. To this end, plant extracts known to contain hydrocolloid polysaccharides and to have mucus-forming properties were studied to evaluate their suitability as saliva substitutes. The aqueous plant extracts of Calendula officinalis, Fucus sp. thalli, and lichenan from Lichen islandicus were examined for composition using a range of techniques, including GC-MS, NMR, SEC, assessment of pH, osmolality, buffering capacity, viscoelasticity, viscoelastic interactions with human saliva, hydrocolloid network formation, and in vitro cell adhesion. For this purpose, a physiologically adapted adhesive test was developed using human buccal epithelial cells. The results show that lichenan is the most promising candidate to mimic the properties of MUC5B. By adjusting the pH, osmolality, and buffering capacity with K2HPO4, it was shown that lichenan exhibited high cell adhesion, with a maximum detachment force that was comparable to that of unstimulated whole mouth saliva.

Identification of a membrane-associated element (MAE) in the C-terminal region of SARS-CoV-2 nsp6 that is essential for viral replication.

The coronavirus disease 2019 (COVID-19) pandemic, caused by the novel coronavirus severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2), has rapidly spread worldwide since its emergence in late 2019. Its ongoing evolution poses challenges for antiviral drug development. Coronavirus nsp6, a multiple-spanning transmembrane protein, participates in the biogenesis of the viral replication complex, which accommodates the viral replication-transcription complex. The roles of its structural domains in viral replication are not well studied. Herein, we predicted the structure of the SARS-CoV-2 nsp6 protein using AlphaFold2 and identified a highly folded C-terminal region (nsp6C) downstream of the transmembrane helices. The enhanced green fluorescent protein (EGFP)-fused nsp6C was found to cluster in the cytoplasm and associate with membranes. Functional mapping identified a minimal membrane-associated element (MAE) as the region from amino acids 237 to 276 (LGV-KLL), which is mainly composed of the α-helix H1 and the α-helix H2; the latter exhibits characteristics of an amphipathic helix (AH). Mutagenesis studies and membrane flotation experiments demonstrate that AH-like H2 is required for MAE-mediated membrane association. This MAE was functionally conserved across MERS-CoV, HCoV-OC43, HCoV-229E, HCoV-HKU1, and HCoV-NL63, all capable of mediating membrane association. In a SARS-CoV-2 replicon system, mutagenesis studies of H2 and replacements of H1 and H2 with their homologous counterparts demonstrated requirements of residues on both sides of the H2 and properly paired H1-H2 for MAE-mediated membrane association and viral replication. Notably, mutations I266A and K274A significantly attenuated viral replication without dramatically affecting membrane association, suggesting a dual role of the MAE in viral replication: mediating membrane association as well as participating in protein-protein interactions.IMPORTANCESevere acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) assembles a double-membrane vesicle (DMV) by the viral non-structural proteins for viral replication. Understanding the mechanisms of the DMV assembly is of paramount importance for antiviral development. Nsp6, a multiple-spanning transmembrane protein, plays an important role in the DMV biogenesis. Herein, we predicted the nsp6 structure of SARS-CoV-2 and other human coronaviruses using AlphaFold2 and identified a putative membrane-associated element (MAE) in the highly conserved C-terminal regions of nsp6. Experimentally, we verified a functionally conserved minimal MAE composed of two α-helices, the H1, and the amphipathic helix-like H2. Mutagenesis studies confirmed the requirement of H2 for MAE-mediated membrane association and viral replication and demonstrated a dual role of the MAE in viral replication, by mediating membrane association and participating in residue-specific interactions. This functionally conserved MAE may serve as a novel anti-viral target.

Deuteration-Driven Photopharmacology: Deuterium-Labeled AzoCholine for Controlling Alpha 7 Nicotinic Acetylcholine Receptors.

Photopharmacology is a powerful approach to investigate biological processes and overcomes the common therapeutic challenges in drug development. Enhancing the photopharmacology properties of photoswitches contributes to extend their applications. Deuteration, a tiny structural modification, makes it possible to improve the photopharmacology and photophysical properties of prototype compounds, avoiding extra complex chemical changes or constructing multicomponent systems. In this work, we developed a series of D-labeled azobenzenes to expand the azobenzene photoswitchable library and introduced the D-labeled azobenzene unit into the photoagonist of α7 nicotinic acetylcholine receptors (α7 nAChRs) to investigate the effects of deuteration in photopharmacology. Spectral data indicated that deuteration maintained most of the photophysical properties of azobenzenes. The D-labeled photoagonist exhibited good control of the activity of α7 nAChRs than the prototype photoagonist. These results confirmed that deuteration is a promising strategy to improve the photopharmacological properties.

Aptameric hirudins as selective and reversible EXosite-ACTive site (EXACT) inhibitors

Potent and selective inhibition of the structurally homologous proteases of coagulation poses challenges for drug development. Hematophagous organisms frequently accomplish this by fashioning peptide inhibitors combining exosite and active site binding motifs. Inspired by this biological strategy, we create several EXACT inhibitors targeting thrombin and factor Xa de novo by linking EXosite-binding aptamers with small molecule ACTive site inhibitors. The aptamer component within the EXACT inhibitor (1) synergizes with and enhances the potency of small-molecule active site inhibitors by many hundred-fold (2) can redirect an active site inhibitor’s selectivity towards a different protease, and (3) enable efficient reversal of inhibition by an antidote that disrupts bivalent binding. One EXACT inhibitor, HD22-7A-DAB, demonstrates extraordinary anticoagulation activity, exhibiting great potential as a potent, rapid onset anticoagulant to support cardiovascular surgeries. Using this generalizable molecular engineering strategy, selective, potent, and rapidly reversible EXACT inhibitors can be created against many enzymes through simple oligonucleotide conjugation for numerous research and therapeutic applications.

Enhancing effect of natural adjuvant, panduratin A, on antibacterial activity of colistin against multidrug-resistant Acinetobacter baumannii

Colistin- and carbapenem-resistant Acinetobacter baumannii is a serious multidrug resistant (MDR) bacterium in clinical settings. Discovery of new antibacterial drugs against MDR is facing multiple challenges in drug development. Combination of known antibiotics with a robust adjuvant might be an alternative effective strategy for MDR treatment. In the study herein, we report an antibiotic adjuvant activity of a natural compound panduratin A from fingerroot (Boesenbergia rotunda) as a potent adjuvant to colistin. The present study investigated the antibiotic adjuvant effect of panduratin A against 10 colistin- and carbapenem-resistant A. baumannii. Antibacterial activities were tested by broth microdilution method. Biofilm assay was used to determine the efficacy of panduratin A in biofilm formation inhibition on two representative strains Aci46 and Aci44. Genomic and transcriptomic analyses of colistin- and carbapenem-resistant A. baumannii strains were used to identify potential resistance and tolerance mechanism in the bacteria. Panduratin A-colistin combination showed an increased effect on antibacterial in the A. baumannii. However, panduratin A did not improve the antibacterial activity of imipenem. In addition, panduratin A improves anti-biofilm activity of colistin against Aci44 and Aci46, the colistin- and carbapenem-resistant A. baumannii. Panduratin A markedly enhances bactericidal and anti-biofilm activity of colistin against colistin- resistant A. baumannii. Based on genome comparisons, single nucleotide polymorphism (SNP) patterns in six genes encoding biofilm and lipid A biosynthesis were shared in Aci44 and Aci46. In Aci44, we identified a partial sequence of pmrB encoding a polymyxin resistant component PmrB, whereas a full length of pmrB was observed in Aci46. RNA-seq analyses of Aci44 revealed that panduratin A-colistin combination induced expression of ribosomal proteins and oxidative stress response proteins, whereas iron transporter and MFS-type transporter systems were suppressed. Panduratin A-colistin combination could promote intracellular reactive oxygen species (ROS) accumulation could lead to the cidal effect on colistin-resistant A. baumannii. Combination of panduratin A and colistin showed a significant increase in colistin efficacy against colistin- resistant A. baumannii in comparison of colistin alone. Genomic comparison between Aci44 and Aci46 showed mutations and SNPs that might affect different phenotypes. Additionally, based on RNA-Seq, panduratin A-colistin combination could lead to ROS production and accumulation. These findings confirmed the potency of panduratin as colistin adjuvant against multidrug resistant A. baumannii.

Predictive insights into plant-based compounds as fibroblast growth factor receptor 1 inhibitors: a combined molecular docking and dynamics simulation study

The discovery of novel therapeutic agents with potent anticancer activity remains a critical challenge in drug development. Natural products, particularly bioactive phytoconstituents derived from plants, have emerged as promising sources for anticancer drug discovery. In this study, we used virtual screening techniques to explore the potential of bioactive phytoconstituents as inhibitors of fibroblast growth factor receptor 1 (FGFR1), a key signaling protein implicated in cancer progression. We used virtual screening techniques to analyze phytoconstituents extracted from the IMPPAT 2.0 database. Our primary objective was to discover promising inhibitors of FGFR1. To ensure the selection of promising candidates, we initially filtered the molecules based on their physicochemical properties. Subsequently, we performed binding affinity calculations, PAINS, ADMET, and PASS filters to identify nontoxic and highly effective hits. Through this screening process, one phytocompound, namely Mundulone, emerged as a potential lead. This compound demonstrated an appreciable affinity for FGFR1 and exhibited specific interactions with the ATP-binding site residues. To gain further insights into the conformational dynamics of Mundulone and the reference FGFR1 inhibitor, Lenvatinib, we conducted time-evolution analyses employing 200 ns molecular dynamics simulations (MDS) and essential dynamics. These analyses provided valuable information regarding the dynamic behavior and stability of the compounds in complexes with FGFR1. Overall, the findings indicate that Mundulone exhibits promising binding affinity, specific interactions, and favorable drug profiles, making it a promising lead candidate. Further experimental analysis will be necessary to confirm its effectiveness and safety profiles for therapeutic advancement in the cancer field. Communicated by Ramaswamy H. Sarma

Computational Approaches to Drug Repurposing: Methods, Challenges, and Opportunities.

Drug repurposing refers to the inference of therapeutic relationships between a clinical indication and existing compounds. As an emerging paradigm in drug development, drug repurposing enables more efficient treatment of rare diseases, stratified patient populations, and urgent threats to public health. However, prioritizing well-suited drug candidates from among a nearly infinite number of repurposing options continues to represent a significant challenge in drug development. Over the past decade, advances in genomic profiling, database curation, and machine learning techniques have enabled more accurate identification of drug repurposing candidates for subsequent clinical evaluation. This review outlines the major methodologic classes that these approaches comprise, which rely on (a) protein structure, (b) genomic signatures, (c) biological networks, and (d) real-world clinical data. We propose that realizing the full impact of drug repurposing methodologies requires a multidisciplinary understanding of each method's advantages and limitations with respect to clinical practice.

Opportunities and challenges in drug development for retinal diseases

Opportunities and challenges in drug development for retinal diseases