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Molecular Pharmaceutics

American Chemical Society (ACS)

Preprints posted in the last 30 days, ranked by how well they match Molecular Pharmaceutics's content profile, based on 16 papers previously published here. The average preprint has a 0.02% match score for this journal, so anything above that is already an above-average fit.

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Structure-Activity Mapping of Intraperitoneal mRNA-LNPs: Decoupling Tumor and Liver Biodistribution in Pancreatic Cancer

Islam, F.; Das, A.; Ashaduzzaman, M.; Ding, L.; Kumari, N.; Dai, R.; Oupicky, D.

2026-03-21 bioengineering 10.64898/2026.03.20.712457 medRxiv
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Pancreatic ductal adenocarcinoma (PDAC) remains difficult to treat with nucleic acid therapeutics because efficient intratumoral delivery is limited and off-target liver accumulation is common. Here, we developed a structure-activity map for intraperitoneally administered mRNA lipid nanoparticles (mRNA-LNPs) to identify formulation features that improve delivery to pancreatic tumors while reducing liver expression. A full-factorial library of 48 mRNA-LNP formulations was generated by varying ionizable lipid, sterol, phospholipid, and PEG-lipid components. Formulations were characterized for size, polydispersity, zeta potential, and encapsulation, then evaluated in an orthotopic KPC8060 pancreatic tumor model after intraperitoneal administration of firefly luciferase mRNA-loaded LNPs. Biodistribution was assessed by Rhodamine B fluorescence and functional delivery by luciferase expression 12 h after dosing. Lipid composition strongly influenced both physicochemical properties and in vivo performance. G0-C14-based formulations produced the smallest and most homogeneous particles, whereas FTT5-containing formulations were generally larger. Across the 48-formulation library, mRNA expression and nanoparticle biodistribution varied significantly among tumor, pancreas, liver, and spleen. Statistical, decision-tree, and predictive modeling analyses identified composition rules associated with organ-selective delivery. High tumor expression was associated primarily with G0-C14 combined with DSPC and {beta}-sitosterol, whereas liver expression was favored by C12-200 or DLin-MC3-DMA with DOPE and DSPE-PEG. Notably, a G0-C14/DSPC/DSPE-PEG formulation emerged as a lead candidate, producing a greater than 6-fold increase in tumor luciferase signal relative to the library median while reducing liver exposure by approximately 60%. Histopathology showed no treatment-related liver or lung toxicity. These findings define actionable formulation rules for tuning intraperitoneal mRNA-LNP delivery in PDAC and support further development of tumor-selective mRNA therapeutics for pancreatic cancer.

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Development and fit for purpose validation of a quantitative LC-MS/MS method for heparan sulfate in cerebrospinal fluid as a biomarker for mucopolysaccharidosis type IIIA

Bystrom, C.; Douglass, K.; Gupta, M.

2026-03-30 genetic and genomic medicine 10.64898/2026.03.27.26348847 medRxiv
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Background: Mucopolysaccharidosis type IIIA (MPS IIIA; Sanfilippo syndrome) is a fatal neurodegenerative lysosomal storage disorder caused by impaired degradation of heparan sulfate (HS). Despite rapid advances in gene and enzyme therapies, there remains a critical need for an analytically validated, quantitative biomarker that accurately reflects central nervous system (CNS) substrate burden. Such biomarker would be a valuable tool in assessing disease progression and monitoring therapeutic efficacy. Objective: This study describes the method development, fit for purpose validation, and preliminary clinical application of a quantitative liquid chromatography-mass spectrometry (LC-MS/MS) assay for the HS-derived disaccharide N-sulfoglucosamine-glucuronic acid (GlcNS-GlcUA) in human cerebrospinal fluid (CSF), a critical biomarker for diagnosis, disease monitoring, and regulatory evaluation of emerging MPS IIIA therapies. Methods: A structurally defined GlcNS-GlcUA reference standard and its [13C6]-labeled internal standard were used in a derivatization and detection workflow employing 1-phenyl-3-methyl-5-pyrazolone labeling, and LC-MS/MS. Results: The method exhibited acceptable linearity across 0.005-0.500 nmol/mL (r[≥]0.9976), with intra- and inter-assay imprecision [≤]3.5%CV and accuracy within 95%-110% of nominal concentrations. No matrix or hemolysis interference or carryover was observed, and the analyte remained stable during freeze-thaw storage conditions. Application of the method to 12 CSF samples from patients with MPS IIIA demonstrated quantifiable GlcNS-GlcUA levels ranging from 0.0054 to 0.106 nmol/mL, confirming suitability for clinical and regulatory use. Comparison of the MPS IIIA sample results between the development laboratory and the contract research organization laboratory support robust inter-lab assay transfer. Conclusions: This validated LC-MS/MS method establishes a regulatory-grade quantitative assay for measurement of CSF HS in MPS IIIA. Its high analytical sensitivity and reproducibility enable reliable assessment of CNS substrate reduction and pharmacodynamic response, supporting biomarker-driven therapeutic development and accelerated approval pathways for neuronopathic mucopolysaccharidoses.

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The structure-interaction model of polymyxin lipopeptides with human oligopeptide transporter 2

Jiang, X.; Luo, Y.; Azad, M. A. K.; Xu, L.; Xiao, M.; Velkov, T.; Roberts, K. D.; Thamlikitkul, V.; Zhou, Q. T.; Zhou, F.; Li, J.

2026-04-02 biochemistry 10.64898/2026.04.01.715775 medRxiv
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BackgroundMultidrug-resistant (MDR) Gram-negative bacteria have triggered a critical global health crisis. Polymyxin lipopeptide antibiotics are used as a last-line therapy against these problematic pathogens, but their clinical use is largely limited by severe nephrotoxicity. Human oligopeptide transporter 2 (hPepT2) is a membrane transporter mediating the reabsorption of polymyxins in renal proximal tubular cells, substantially contributing to their nephrotoxicity. However, it remains unclear how polymyxins interact with hPepT2. MethodsIn this study, we investigated the structure-interaction relationship (SIR) of polymyxins with hPepT2 by integrating computational, chemical and cell biology approaches. Bioinformatic modelling predicted the residues essential for the binding of polymyxins with hPepT2. Transporter mutagenesis and molecular analysis were employed to explore the role of each residue in the interaction of hPepT2 and polymyxins. Moreover, we synthesised a series of polymyxin-like analogues with altering the moieties that are critical for binding with hPepT2. The antibacterial activity and nephrotoxicity of these analogues were subsequently assessed. ResultsOur bioinformatic modelling proposed an outward-facing structure of hPepT2 with a possible transport pathway that polymyxins bind to the lateral opening site of hPepT2 (e.g. E214, D215, D317, D342, E622). Molecular assays for transporter function and expression confirmed that D215 residue of hPepT2 is critical for polymyxin binding, while several other residues significantly impact on transporter turnover rate and/or protein expression. Our experimental validations showed that the lipopeptide analogues with altering the Dab1, Dab3, Dab5 and Dab9 moieties of polymyxins demonstrated decreased interactions with hPepT2. Among these synthetic analogues, alanine substitution at Dab3 showed reduced nephrotoxicity in mice while reserved antibacterial activity against a range of bacterial strains. ConclusionsOverall, this proof-of-concept study demonstrated that the computationally predicted and experimentally validated polymyxin-hPepT2 SIR model provides a viable approach for the discovery of novel, safer lipopeptide antibiotics.

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Nanoparticle-in-Microparticle Oral Delivery System Based on Drug-Loaded Polymeric Micelles

Moshe Halamish, H.; Sverdlov Arzi, R.; SOSNIK, A.

2026-03-19 pharmacology and toxicology 10.64898/2026.03.17.712272 medRxiv
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This work develops and characterises a hierachichal oral drug delivery system based on the microencpasulation of drug-loaded amphiphilic nanogels within a mucoadhesive alginate/chitosan shell. Results show a more controlled release and a statistically significant oral half-life with respect to the free drug.

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Nanoparticle encapsulation enhances spatial distribution of Panobinostat to treat metastatic medulloblastoma via the intrathecal route

Babayemi, O.; Larson, J. D.; Chaudhuri, S.; Valesquez, F.; Morton, J.; Kuo, C.-F.; Sablatura, L. K.; Baquer, G.; Reagan, M. S.; Stopka, S.; Sandberg, D. I.; Agar, N. R.; Sevick-Muraca, E.; Wechsler-Reya, R. J.; Sirianni, R. W.

2026-04-02 bioengineering 10.64898/2026.03.31.715392 medRxiv
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Medulloblastoma (MB) is an aggressive central nervous system (CNS) malignancy that primarily affects children and frequently exhibits metastasis to the leptomeninges of the brain and spinal cord. We developed a {beta}-Cyclodextrin-poly({beta}-Amino Ester) nanoparticle system to deliver the histone deactylase inhibitor (HDACi) Panobinostat to MB by the intrathecal route. Various imaging methods were utilized to study nanoparticle and payload fate following infusion into the cerebrospinal fluid (CSF) of mice via cisterna magna or lumbar access points. Nanoparticles dramatically improved penetration of hydrophobic small molecules into distal regions of the spinal cord. Panobinostat-loaded nanoparticles were effective at treating patient-derived MB, activating pharmacodynamic targets, slowing growth of the primary tumor, decreasing incidence of metastasis at the time of death, and ultimately prolonging survival. These studies provide insight into the mechanisms mediating transport of colloids and therapeutic molecules in the subarachnoid space and highlight new approaches for treating metastatic disease in the CNS.

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Exofection as a Therapeutic Modality: Restoring P-gp Activity via Trophoblast-Derived EV in Neuroinflammatory Disorders

Kammala, A. K.; Tatiparthy, M.; Sreenivasa Murthy, S. G. S.; Garza, K.; Budhwani, S.; Richardson, L. S.; Menon, R.; Krishnan, B.

2026-04-06 pharmacology and toxicology 10.64898/2026.04.02.716001 medRxiv
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BackgroundP-glycoprotein (P-gp/ABCB1) is a key efflux transporter that maintains barrier integrity by clearing xenobiotics and toxic metabolites. At the feto-maternal interface, trophoblast-derived extracellular vesicles (CTC-EVs) naturally and transiently transfer functional P-gp to maternal decidual cells, restoring lost and or reduced P-gp function (exofection) to sustain pregnancy homeostasis. A similar loss of P-gp at the blood brain barrier (BBB) contributes to impaired amyloid-{beta} (A{beta}) clearance and neuroinflammation in Alzheimers disease. We investigated whether CTC-EV-mediated exofection could restore P-gp function in human brain endothelial cells (hBECs) and enhance A{beta} clearance under inflammatory and neurodegenerative conditions. MethodsCTC-EVs were isolated and characterized by nanoparticle tracking analysis and western blotting for P-gp and EV markers. Transcriptomic profiling of CTC-EVs identified enrichment of transporter-related genes, including solute carriers and ABC transporters, along with inflammatory mediators. Network analysis revealed coordinated modules linking EV cargo to transporter regulation, endocytosis/trafficking pathways, and inflammatory remodeling processes converging on BBB efflux activity. hBECs were exposed to LPS (500 ng/mL, 48 h) with or without CTC-EVs. P-gp expression was assessed by immunofluorescence (mean fluorescence intensity, MFI) and western blotting, while functional efflux was measured using Calcein-AM assays. A{beta} oligomer transport was evaluated using a transwell hBEC model. In vivo, 3xTg-AD mice received intravenous CTC-EVs (1x10L/day for 5 days), followed by assessment of P-gp expression, A{beta} burden, and neuroinflammatory markers. Pharmacokinetic studies in P-gp knockout mice were conducted to confirm functional transporter recovery. ResultsLPS exposure significantly reduced P-gp expression in hBECs (41.3% decrease in MFI, p=0.0084), which was restored by CTC-EVs (46.7% increase vs. LPS, p=0.0121). Exofection increased P-gp by a 2.1-fold following EV treatment as determined by western blot. Functional assays demonstrated enhanced efflux, with a 38.5% reduction in intracellular Calcein fluorescence (p<0.001). Network-informed mechanisms supported coordinated regulation of transporter and trafficking pathways. CTC-EVs improved A{beta} transport across inflamed hBEC monolayers. In vivo, EV-treated 3xTg-AD mice exhibited increased P-gp expression in the frontal cortex (38.6%) and hippocampus (42.1%), reduced A{beta} plaque burden (27.9%), and decreased inflammatory markers (IL-1{beta} and TNF-, p<0.05). In P-gp knockout mice, EVs reduced brain drug accumulation by 22.4% (p=0.032), confirming restoration of transporter function. ConclusionCTC derived EVs are natural carriers of functional transporter proteins and restore efflux capacity in compromised endothelial barriers. Integration of transcriptomic and network analyses highlights coordinated regulation of transporter, trafficking, and inflammatory pathways underlying exofection. This reproductive biology inspired strategy offers a promising therapeutic approach for enhancing A{beta} clearance and mitigating neuroinflammation in Alzheimers disease.

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Study comparing characteristics of ademetionine-containing tablets from different countries

Mato, J. M.; Wong, G. L.; Gooijer, Y.; Safaei, A.

2026-03-30 pharmacology and toxicology 10.64898/2026.03.27.714742 medRxiv
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Background/ObjectivesThe quality and characteristics of approved medicines can vary substantially depending on manufacturing processes and standards within a given country. The aim of the study was to compare the available marketed brands of ademetionine tablets derived from various countries in order to identify potential differences between the different formulations. MethodsWe performed comprehensive analyses of the physical, chemical, and dissolution characteristics of different formulations of ademetionine tablets marketed in China, India, Russia, Ukraine, and Uzbekistan, using the originator formulation of Heptral(R) as the reference standard. The formulations were evaluated at initial analysis and after 3 months at 40{degrees}C/75% relative humidity. Clinical parameters such as ademetionine content, degradation products, S,S-isomer, and water content were assessed using HPLC, and a dissolution profile analysis performed in 2 hours of acid solution followed by 90 minutes in a buffer solution. ResultsThe Nusam (India) and Ximeixin (China) products were the two products most comparable to the Heptral products. Adenomak (Ukraine), the only food-grade product and only one with the tosylate salt showed the most significant quality variations compared to Heptral including dissolution failure as well as considerable variability between batches. ConclusionsThe study highlights the importance of using pharmaceutical-grade ademetionine products to maintain clinical efficacy and ensuring standards are maintained across global markets.

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Stereoselective binding of prasugrel active metabolite to the P2Y12 receptor: insights from a molecular modeling approach

Allemand, F.; Le Bras, L.; Davani, S.; Ramseyer, C.; Lagoutte-Renosi, J.

2026-03-27 biophysics 10.64898/2026.03.26.713933 medRxiv
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Prasugrel is a prodrug, widely used in antiplatelet strategy for secondary prevention after acute coronary syndrome. The metabolism of prasugrel leads to the formation of the Prasugrel Active Metabolite (PAM), an irreversible P2Y12 receptor antagonist. Its mode of binding has not yet been fully established, although it is known that it binds covalently to P2Y12 by forming a disulfide bridge with cysteines and its sulfur moiety. PAM is a molecule with two chiral centers, resulting in four stereoisomers which appear to be stereoselective upon binding. A combination of different molecular modeling methods, such as molecular dynamics, ensemble docking, and Density Functional Theory (DFT), were used to rationalize these differences in antagonism observed in vitro and to elucidate the mode of binding of PAM to P2Y12. PAM is found to bind to the closed P2Y12 conformation in a preferential way. Although the four stereoisomers have comparable affinity, the location of the RS stereoisomer makes the formation of a disulfide bond with cysteines more favorable, particularly with cysteine 175. Compared to the RR stereoisomer, the RS stereoisomer interacts less deeply with the P2Y12 receptor, interacting in particular with the second and third extracellular loops, explaining the competition observed with cangrelor and an intermediate metabolite of prasugrel. Furthermore, DFT calculations have shown that the formation of a disulfide bridge is energetically more favorable with the RS stereoisomer than with the RR stereoisomer. The physical interactions and chemical reaction between the RS stereoisomer and the P2Y12 receptor are key factors in explaining the stereoselective binding of PAM to P2Y12.

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Construction of a GnRH mRNA Immunocastration Vaccine and Evaluation of Its Immunogenicity and Safety in Mice and Cats

Chen, Y.; Dong, C.; Yan, W.; Liu, Y.; Sun, J.; Ji, M.; Gang, J.; Nie, J.; Zhang, X.; Huang, H.; Zhou, y.

2026-03-26 immunology 10.64898/2026.03.25.714088 medRxiv
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Immunocastration has emerged as an alternative to surgical and chemical castration for managing reproductive function in animals, yet the development of safe and effective vaccines remains challenging. This study aimed to develop a gonadotropin-releasing hormone (GnRH)-based messenger RNA (mRNA) vaccine and systematically evaluate its immunogenicity, reproductive suppression efficacy, long-term durability, and biosafety in mice and cats. GnRH epitopes were fused to three carrier proteins, Fc, Foldon, and lumazine synthase nanoparticles (pLS) via a flexible linker. After identifying pLS as the optimal scaffold, three mRNA vaccine candidates (GnRH-3, GnRH-4, and GnRH-5) were generated with one, five, or ten tandem GnRH repeats, encapsulated in lipid nanoparticles (LNPs), and assessed in rodent and feline models. Immunogenicity was determined by enzyme-linked immunosorbent assay, gonadal histopathology, hormone measurements, transcriptomic analysis, and mating trials. Among the fusion partners, the pLS-based vaccine (GnRH-3) induced the strongest antibody responses and most pronounced reproductive suppression. Further optimization showed that GnRH-4, containing five tandem GnRH repeats, elicited the highest antibody titers, induced severe gonadal atrophy, and reduced litter size by 93.8% in mice. Transcriptomic analysis revealed that differentially expressed genes in males were enriched in spermatogenesis and motility pathways, whereas those in females were associated with RNA splicing and immune responses. In cats, the optimal regimen was a twoLdose schedule with 50Lg per dose and a 21Lday interval, which induced robust antibody responses lasting at least 12 Lmonths and sustained reproductive suppression. HighLdose (500Lg) administration showed no clinical toxicity or histopathological abnormalities, confirming favorable biosafety. This study successfully developed a pLSLbased GnRH mRNA vaccine (GnRH-4) with five tandem GnRH epitopes that demonstrates strong immunogenicity, longLlasting contraceptive effects, and excellent safety in both rodent and feline models, supporting its potential for clinical application in immunocastration.

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Anti-oxidant and anti-inflammatory Effects of Aerosolised microalgal-derived extracellular vesicles in Bronchial Epithelial-Macrophage Co-cultures at the Air-Liquid Interface

Darwish, W.; Adamo, G.; Almasaleekh, M.; Picciotto, S.; Gargano, P.; Romancino, D.; Raccosta, S.; Zimmermann, R.; Manno, M.; Bongiovanni, A.; Di Bucchianico, S.

2026-03-23 pharmacology and toxicology 10.64898/2026.03.19.712886 medRxiv
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AbstractInflammation and oxidative stress are key drivers in the pathogenesis of chronic lung diseases, including asthma, pulmonary fibrosis, and chronic obstructive pulmonary disease. Extracellular vesicles derived from the marine microalga Tetraselmis chuii, referred to as nanoalgosomes, have recently gained attention as natural nanocarriers that possess inherent antioxidant and anti-inflammatory properties. In this study, we investigated the biocompatibility and protective effects of aerosolized nanoalgosomes in a bronchial epithelial-macrophage co-culture model at the air-liquid interface. Co-cultures of CALU-3 epithelial cells and differentiated THP-1 macrophages were primed with aerosolised nanoalgosomes and subsequently exposed to either oxidative stress (tert-butyl hydroperoxide) or an inflammatory stimulus (lipopolysaccharide; LPS). Epithelial barrier integrity and cytotoxicity were evaluated using transepithelial electrical resistance and lactate dehydrogenase release assays, respectively, while intracellular reactive oxygen species levels and cytokine secretion were measured to assess antioxidant and immunomodulatory responses. Nanoalgosomes were non-cytotoxic, preserved epithelial barrier integrity, and significantly reduced oxidative stress. In addition, nanoalgosomes priming attenuated LPS-induced secretion of pro-inflammatory cytokines (IL-1{beta}, IL-6, IL-8, IL-18, TNF-) as well as the anti-inflammatory cytokine IL-10, suggesting a balanced immunomodulatory response. Overall, aerosolized nanoalgosomes maintained epithelial homeostasis and mitigated both oxidative and inflammatory stress, underscoring their potential as a safe, sustainable, and effective therapeutic strategy for chronic inflammatory lung diseases. Given their natural origin, excellent biocompatibility, and suitability for aerosol delivery, nanoalgosomes represent a promising class of inhalable biotherapeutics.

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A scalable and equitable framework for target and patient prioritisation in rare disease antisense therapeutics

Whittle, E. F.; Montgomery, K.-A.; Camps, C.; Elkhateeb, N.; Ryan, C.; Aguti, S.; de Guimaraes, T. A. C.; Kini, U.; Stewart, H.; Douglas, A. G. L.; Wilson, L.; Leitch, H. G.; Lynch, D. S.; Robinson, R.; Michaelides, M.; Yu, T. W.; Gissen, P.; Lauffer, M. C.; Lench, N.; O'Connor, D.; Tavares, A. L.; Sanders, S. J.; Kurian, M. A.; Titheradge, H.; Clement, E.; van der Spuy, J.; Taylor, J. C.; Rinaldi, C.; Muntoni, F.; Zhou, H.; Davidson, A. E.; Ryten, M.; UPNAT consortium,

2026-03-26 genetic and genomic medicine 10.64898/2026.03.23.26348690 medRxiv
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BackgroundNucleic acid therapies (NATs) comprise engineered DNA- or RNA-based medicines that act through sequence-specific interactions to modify gene function. Among these, antisense oligonucleotide (ASO) therapies are designed to bind messenger RNA (mRNA) or pre-mRNA to alter splicing, transcript stability, or translation. Many patients with a rare genetic disease stand to benefit from these treatments and, as underlying technologies continue to advance, a critical barrier to care is the equitable selection of targets and patients. Owing to landmark progress in genomic health care, the UK is uniquely positioned to develop a national framework on NAT patient-selection infrastructure. The UK Platform for Nucleic Acid Therapies (UPNAT) has been launched, in part, to meet this goal, with a key output being a structured patient and target selection framework to support NAT development and clinical application, using ASO therapies as a pilot modality. Methodology and ResultsA multidisciplinary panel of UK-based experts established the UPNAT framework to enable systematic assessment of ASO amenability across modular domains encompassing disease understanding, functional models, variant characteristics, and the individual patient, incorporating the recently published N1C VARIANT guidelines. This modular structure supports consistent prioritisation of tractable targets while identifying biological, clinical, technical, or evidentiary gaps currently limiting ASO development. Designed for implementation within the UK healthcare infrastructure and amenable to future automation using open-access resources, the framework was iteratively refined through application to genomic and clinical data from approved ASO therapies and selected real-world patient case studies. ConclusionWe present the first disease-agnostic framework to support structured prioritisation of patients and targets (diseases, genes, or variants) for ASO development and consideration within specialist healthcare services. Designed to accommodate rapid technological advances in NATs, the framework promotes transparent, equitable, and reproducible decision-making within the UK National Health Service (NHS), with principles transferable to other healthcare systems.

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Structural Basis of M1 Muscarinic and H3 Histamine Receptor Inhibition in OPC Differentiation

Raubenolt, B.; Cumbo, F.; Joshi, J.; Martin, W.; Medicetty, S.; Yang, Y.; Trapp, B.; Blankenberg, D.

2026-04-02 biophysics 10.64898/2026.04.01.715893 medRxiv
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Muscarinic and histamine receptors are neurotransmitter-binding proteins within the large family of G protein-coupled receptors (GPCRs) and are relevant to human health and disease, including multiple sclerosis (MS), a chronic immune-mediated inflammatory demyelinating disease of the central nervous system (CNS) with neurodegenerative components. MS affects approximately 1 in 333 people, and women are affected at roughly threefold higher rates than men. A major pathological feature of MS is demyelination with incomplete remyelination of axons in the CNS. Because oligodendrocyte progenitor cells (OPCs) can differentiate into mature oligodendrocytes that restore myelin, small molecules that promote OPC differentiation represent a potential therapeutic strategy. High-throughput screening identified 18 hit compounds with EC50 values below 0.2 M, including the lead compound CN045, which showed an EC50 of 40 nM in vitro. Cheminformatic and experimental target-identification studies implicated the M1 muscarinic receptor and the H3 histamine receptor as candidate targets. To interpret these findings, we performed docking, molecular dynamics simulations, and binding free-energy analyses on complexes involving CN045 and clemastine, a known antihistamine with antimuscarinic activity. The simulations support weaker and less stable binding of CN045 to H3 than to M1 and identify residue-level interactions that contribute to stability within the M1 binding pocket. Comparisons between CN045 and clemastine at M1 further suggest that the two ligands sample different local conformational ensembles, including differences in conserved microswitch behavior associated with active-like versus inactive-like receptor states. Together, these results provide a structural framework for understanding ligand-specific M1 engagement and may help guide future optimization of remyelination-promoting compounds.

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Microencapsulated Vaccinium floribundum Kunth extract promotes angiogenesis and attenuates inflammation in in vitro and in vivo models.

Antognoni, F.; Tubon, I.; Biondolillo, G.; Melotti, L.; Di Lecce, R.; Afifi, S. M.; Vaca, G.; Salaroli, R.; Vacacela Gomez, C.; Zambrano Cardenas, G. O.; Forni, M.; Zannoni, A.; Bernardini, C.

2026-03-24 pharmacology and toxicology 10.64898/2026.03.20.713210 medRxiv
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Natural products, especially polyphenol-rich medicinal plants, are increasingly investigated as multitarget therapeutics in both human and veterinary medicine for angiogenic regenerative properties and for inflammation based-diseases. Recent developments in natural product formulation, notably microencapsulation, have been shown to improve the stability, bioavailability, and controlled release of bioactive compounds. The integration of complementary in vitro and in vivo models is critical for evaluating both efficacy and translational potential. In this context, the present study assessed the phytochemical composition and biological activity of a microencapsulated Ecuadorian Vaccinium floribundum extract (VFM), using a combination of in vitro and in vivo approaches. VFM biochemical characterization identified 15 compounds, including flavonoids, procyanidins, dihydrochalcones, and phenolic acids, with chlorogenic acid and quercetin as the most abundant metabolites. Anthocyanins ideain and petunidin were also detected, confirming a rich bioactive profile. Primary porcine thoracic aortic endothelial cells (pAECs) were treated with VFM to assess cell viability and angiogenic potential and challenged with bacterial lipopolysaccharide (LPS) in the presence or absence of the extract. Anti-inflammatory effects were further evaluated in vivo using a carrageenan-induced mouse paw edema model. VFM enhanced endothelial cell viability, promoted capillary-like network and modulated early angiogenic signaling pathways. It mitigated LPS-induced endothelial dysfunction by reducing pro-inflammatory cytokines and oxidative stress markers. In vivo, paw edema assays confirmed its anti-inflammatory efficacy, with microencapsulation likely sustaining bioactive release. These findings support the traditional use of Vaccinium floribundum and highlight its potential for developing nutraceutical formulations targeting vascular and inflammatory disorders.

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In vivo pharmacokinetics and tissue distribution profile of a Wnt/β-catenin pathway-targeting anticancer cassane diterpene isolated from Caesalpinia pulcherrima

De Vass Gunawardane, S.; Epitawala Arachchige, O. V.; Wijerathne, S. K.; Punyasiri, P. A. N.; Murugananthan, A.; Samarakoon, S. R.; Senathilake, K. S.

2026-04-01 pharmacology and toxicology 10.64898/2026.03.30.715187 medRxiv
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A cassane diterpene, 6{beta}-cinnamoyl-7-hydroxyvouacapen-5-ol (6{beta}CHV), isolated from Caesalpinia pulcherrima, has emerged as a promising anticancer drug lead with reported Wnt/{beta}-catenin pathway inhibitory activity and in vivo safety. The present study reports the in vivo pharmacokinetics and tissue distribution of 6{beta}CHV in Wistar rats following a single oral dose of 200 mg/kg. A reproducible RP-HPLC-UV method was developed and validated for quantifying 6{beta}CHV in rat plasma and tissues. Chromatographic separation was achieved using a gradient elution of methanol and water. The method was subsequently applied to investigate the pharmacokinetics and tissue distribution of 6{beta}CHV. Plasma pharmacokinetic analysis revealed delayed and moderate absorption, with a Tmax of 4 h and a Cmax of 1314.12 ng/mL. Following absorption, 6{beta}CHV is distributed widely across peripheral tissues, including the liver, heart, lungs, spleen, and kidneys, as well as pharmacological sanctuary sites such as the brain and testes. The highest concentrations were observed in the stomach, small intestine, and liver, with detectable levels persisting up to 24 h, reflecting extensive tissue partitioning and retention. Overall, these findings demonstrate that oral administration of 6{beta}CHV is feasible. However, the delayed absorption suggests that further optimization of formulation or alternative administration routes may enhance systemic exposure. This study provides the first comprehensive pharmacokinetic and tissue distribution profile of 6{beta}CHV, supporting its continued preclinical development as a potential anticancer therapeutic. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=125 SRC="FIGDIR/small/715187v1_ufig1.gif" ALT="Figure 1"> View larger version (18K): org.highwire.dtl.DTLVardef@4ae86forg.highwire.dtl.DTLVardef@1e1e51aorg.highwire.dtl.DTLVardef@1881c43org.highwire.dtl.DTLVardef@f7789f_HPS_FORMAT_FIGEXP M_FIG C_FIG

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Nonlinear Mixed-Effects and Full Bayesian Population Pharmacokinetic Analysis of Ceftolozane-Tazobactam in Critically Ill Patients

Okunska, P.; Borys, M.; Rypulak, E.; Piwowarczyk, P.; Szczukocka, M.; Raszewski, G.; Czuczwar, M.; Wiczling, P.

2026-03-26 pharmacology and toxicology 10.64898/2026.03.24.713879 medRxiv
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1.Pharmacokinetic studies in critically ill patients are often constrained by small sample sizes, limiting the strength and generalizability of conclusions drawn solely from observed data. Bayesian inference offers a powerful strategy to address this challenge by incorporating prior knowledge. In this study, we evaluated two model-based approaches for characterizing the population pharmacokinetics of ceftolozane and tazobactam in critically ill patients, comparing nonlinear mixed-effects modeling with Bayesian hierarchical analyses. The Bayesian methods incorporated literature-derived prior information. The data was collected from 13 critically ill patients receiving 3.0 g of ceftolozane combined with tazobactam (2:1) via intravenous infusion. Pharmacokinetic modeling was performed using NONMEM and Stan software with the Torsten extension. Model diagnostics and graphical analyses were conducted in RStudio with relevant packages. In the absence of prior information, a one-compartment model with a limited set of parameters describing inter-individual variability adequately characterized the pharmacokinetics of ceftolozane and tazobactam. When prior information was incorporated, a two-compartment model became feasible and yielded a characterization of parameter variability and correlations that was more consistent with published literature. The application of Bayesian inference ensured alignment with existing literature on ceftolozane and tazobactam pharmacokinetics and mitigated some systematic biases observed in the data-driven approaches. Moreover, the Bayesian approach enables direct decision-making by incorporating uncertainty into the analysis, as demonstrated by probability of target attainment analysis. Collectively, these results underscore the utility of Bayesian methods in pharmacokinetic modeling for critically ill patients, offering a robust framework for optimizing dosing strategies in data-limited settings.

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Polystyrene Nanoplastics Accumulate in Murine Cortex and Induce Transient Microglial Activation via Endolysosomal Retention

Tavakolpournegari, A.; Kannan, U.; Gregory, M.; Dufresne, J.; Costantino, S.; Lefrancois, S.; Cyr, D. G.

2026-03-26 pharmacology and toxicology 10.64898/2026.03.24.712727 medRxiv
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Environmental degradation and accumulation of plastics results in micro- and nanoplastics (MNPLs) that are small enough to cross biological barriers, including the blood-brain barrier. Microglia, resident immune cells of brain, are critical regulators of neuroimmune homeostasis and represent a cellular target of nanoplastic exposure. In this study, we assessed the neurotoxic effects of two sizes of polystyrene nanoplastics (PS-NPs; 100 nm and 500 nm) using integrated in vivo and in vitro exposure and washout paradigms. In vivo exposure in mice (60 days; 0.15 or 1.5 mg/day) showed the accumulation of both PS-NP sizes in the cerebral cortex without histopathological damage. However, cortical microglia showed pronounced morphological remodeling, observed as increased expression of Iba1 and GFAP. Transcriptomic profiling of cortical tissue revealed a strong size-dependent response. The 100 nm PS-NP group revealed 18 DEGs (|log2FC| [&ge;] 2, padj < 0.05), whereas the 500 nm PS-NPs showed more than 4,000 DEGs, including upregulation of immune- and microglia-associated genes (CCL5, CXCL10, LCN2, LYZ2) and downregulation of synaptic and neuronal signaling genes (GRIN2B, SYN1, STX1B, MAP1B, ITPR1/2). In vitro assessment, using BV2 microglia cells, showed internalization of PS-NPs via the endolysosomal pathway, with strong co-localization to Rab7- and LAMP2-positive compartments and prolonged intracellular retention following exposure washout. Also, microglial activation markers (Iba1, CD68) exhibited a transient, size- and concentration-dependent increase, correlated with intracellular particle burden rather than cumulative exposure. Overall, these findings demonstrate that PS-NPs accumulate in brain, driving size-dependent microglia activation and transcriptomic reprogramming, even after cessation of exposure to PS-NPs. HighlightsO_LIPS-NPs (100 nm and 500 nm) reach mouse cerebral cortex following 60-day oral exposure. C_LIO_LIPS-NPs were internalized by microglia; accumulated in endolysosomal compartments. C_LIO_LIPS-NP exposure induced transient microglial activation without sustained cytotoxicity. C_LIO_LIMicroglial activation was correlated with intracellular PS-NPs burden. C_LIO_LITranscriptomics revealed disruption of neuroimmune and microglial regulatory pathways. C_LI O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=128 SRC="FIGDIR/small/712727v1_ufig1.gif" ALT="Figure 1"> View larger version (27K): org.highwire.dtl.DTLVardef@1aba3eaorg.highwire.dtl.DTLVardef@1967641org.highwire.dtl.DTLVardef@12da637org.highwire.dtl.DTLVardef@1fb8441_HPS_FORMAT_FIGEXP M_FIG C_FIG

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Adherence to International Pharmacogenomic Recommendations in Paediatric Cancer Care: A Cohort Analysis Embedded Within the MARVEL-PIC Randomised Trial

Chawla, A.; Carter, S.; Dyas, R.; Williams, E.; Moore, C.; Conyers, R.

2026-04-16 genetic and genomic medicine 10.64898/2026.04.15.26348678 medRxiv
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Background: Pharmacogenomic testing (PGx) can optimise drug efficacy and minimise toxicity, but the extent of prescriber adherence to PGx recommendations remains unclear. We aimed to quantify clinician adherence to international genotype-guided prescribing recommendations in a cohort of paediatric oncology patients. Methods: We reviewed files of children enrolled in the MARVEL-PIC (NCT05667766) randomised control trial, who had PGx recommendations available. Patients were included if 12 weeks had passed since their PGx report was released to clinicians. Prescribing events were identified for actionable PGx recommendations, and classified as "explicitly followed", "inadvertently followed", or "not followed". Adherence was assessed by patient, drug, and recommendation. Results: 2,063 PGx recommendations were available for 216 patients. 64 (3.1%) recommendations were actionable for 44 patients and 10 drugs within the 12-week study period. Recommendations were explicitly followed in 57/288 (19.8%) of prescribing events, inadvertently followed in 145 (50.3%), and not followed in 86 (29.9%). Mercaptopurine demonstrated the highest rate of explicit adherence (87.5%). No significant associations were observed between adherence and age group, cancer type, drug type, or strength of recommendation. Conclusion: Adherence to pharmacogenomic recommendations was very low, highlighting the need to understand barriers to PGx implementation, and consideration of clinical decision supports to facilitate adherence.

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Integrating Computational Optimization with Antimicrobial Susceptibility Testing: A Particle Swarm Optimization Framework for Enhancing Fluoride Toothpaste Formulations

Asuai, C.; Whiliki, O.; Mayor, A.; Victory, D.; Imarah, O.; Irene, D.; Merit, I.; Hosni, H.; Khan, M. I.; Edwin, A. C.

2026-03-27 dentistry and oral medicine 10.64898/2026.03.25.26349293 medRxiv
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This study develops a methodological framework that combines conventional antimicrobial susceptibility testing with Particle Swarm Optimisation (PSO) to enhance toothpaste formulations, employing Escherichia coli isolated from the oral cavity as a model organism. We used the agar well diffusion method to see if two fluoride toothpastes (Oral B and My-my) could kill oral E. coli isolates at 6.25%, 12.5%, 25%, 50%, and 100% concentrations. A surrogate Random Forest model was created using these experimental data to link formulation parameters to antimicrobial activity. Then, PSO was used to find the best formulation traits. Multi-objective optimisation that looks at the trade-offs between antimicrobial effectiveness and cytotoxicity was shown as a conceptual framework. Both toothpastes showed antimicrobial activity that depended on the concentration, with Oral B being more effective (23.0 mm at 100% concentration) than My-my (20.0 mm). The PSO framework, utilised as a methodological illustration while explicitly recognising data constraints, determined hypothetical formulation parameters (sodium fluoride 1100 ppm, hydrated silica abrasive, 2.5% SLS) with an anticipated zone of inhibition of 26.3 mm. These predictions are mathematically optimal for a surrogate model that was trained on very little data (n=10 formulation points). They need a lot of experimental testing before any claims about the formulation can be made. This work is presented as a proof-of-concept methodological framework, not as validated formulation guidance.

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Pro-domain-dependent folding and co-receptor-mediated targeting to optimize an antagonistic TGF-β monomer for gene-based delivery

Wieteska, L.; Hinck, C. S.; Mukundan, A.; Krzysiak, T.; van Dinther, M.; Vantieghem, T.; Maizels, R. M.; ten Dijke, P.; Hill, C. S.; Hinck, A. P.

2026-03-24 bioengineering 10.64898/2026.03.23.713733 medRxiv
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Transforming growth factor-beta (TGF-{beta}), a potent promoter of extracellular matrix deposition and suppressor of infiltrating immunity, has arisen as an attractive target for improving outcomes in tissue fibrosis and cancer immune therapy. Despite the promise of TGF-{beta} inhibitors for attenuating the progression of fibrotic disorders or as adjuncts for cancer immunotherapy, current systemically administered inhibitors that target the ligand or receptors have significant on-target liabilities, including cardiotoxicity and development of pre-malignant cutaneous squamous lesions. Recently, an engineered mini monomer of TGF-{beta} (mmTGF-{beta}), which potently and specifically inhibits TGF-{beta} activity, was shown to strongly synergize with checkpoint inhibitors to suppress cancer progression in an aggressive model of melanoma when genetically delivered using an engineered form of vaccinia virus that preferentially infects cancer cells. Despite these promising results, however, a significant fraction of the mmTGF-{beta} was found to misfold, likely due to mispairing of the cysteines that comprise its cystine knot. Here, we demonstrate that inclusion of a modified form of the TGF-{beta} pro-domain that lacks its dimerization motif, the bowtie knot, dramatically improves both the folding and inhibitory activity upon secretion by mammalian cells, thus overcoming one of the major limitations of genetically delivering mmTGF-{beta}. Furthermore, we show that fusion of mmTGF-{beta} to a CD44 binding domain enhances the inhibitory potential of mmTGF-{beta} on immune cells, and on other cell types which express CD44, by more than 30-fold compared to cells negative for CD44. Together, these modifications provide a framework for further enhancing the efficacy and safety of mmTGF-{beta} for cancer immune therapy, and possibly also tissue fibrosis, when delivered genetically using vaccinia, or other related approaches.

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Anti-HIV Immunotoxin and Antibody-Drug Conjugate Display Both Common and Distinct Effects in Killing Target Cells

PINCUS, S.; Peters, T.; Stackhouse, M. S.; O'Shea-Stone, G.; Cole, F. M.; Tripet, B.; Copie, V.

2026-04-10 immunology 10.64898/2026.04.07.717054 medRxiv
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BackgroundIn the course of testing mAb-based therapies to eradicate the persistent reservoir of HIV infection, we investigated the efficacy and mode of killing of HIV-infected cells by two categories of cytotoxic immunoconjugates (CICs) targeted by the same mAb, an immunotoxin (IT) and antibody-drug conjugate (ADC). MethodsWe performed metabolic and transcriptional analyses of treatment effects on the persistently-infected cell line H9/NL4-3. Cells were treated with CICs consisting of the anti-gp41 mAb 7B2 conjugated to either deglycosylated ricin A chain (dgA) or to the highly cytotoxic anthracycline derivative PNU-159682. At intervals up to 24 hr, intracellular metabolites were quantified by 1H nuclear magnetic resonance spectroscopy, and the transcriptome analyzed by RNA-Seq. ResultsSix hr post treatment, 7B2-dgA elicited both metabolic and transcriptional alterations, whereas 7B2-PNU treated cells did not differ from untreated cells. 7B2-dgA treated cells exhibited elevated intracellular levels of many amino acids, and activation of gene pathways for apoptosis, intracellular signaling, and immune activation. By 24 hr, both 7B2-dgA and 7B2-PNU treated cells differed markedly from untreated. Many of the changes observed following 7B2-PNU treatment at 24 hr were similar to those observed at 6hr following 7B2-dgA, likely indicating processes involved in cell death, but a number of alterations were unique to either IT or ADC treated cells. ConclusionsAn IT and ADC showed both similarities and differences in their cytotoxic effects. These results raise the question of whether the mode of cell killing could be a determinant of clinical efficacy. Although these studies were aimed at targeting the persistent reservoir of HIV infection, they have relevance for the design of CICs to treat cancer and other conditions. SUMMARYThe use of cytotoxic immunoconjugates, wherein an antibody is attached to a cellular poison, is effective in the treatment of cancer and other conditions. We seek to extend these results to treating HIV and other chronic viral infections. We analyzed the molecular mechanisms of cell killing when the same antibody was attached to different toxic structures. We report that each immunoconjugate induced both common and distinct patterns of killing. Such differences may have clinical relevance.