Katarzyna Ewa Greber

Developmental and adult neurotoxicity are hard to assess with conventional in vitro assays, which rarely account for how a chemical actually distributes once inside the body. Biomimetic chromatography offers a practical way to fill that gap, using stationary phases that mimic phospholipid membranes and major plasma proteins to yield experimental descriptors of lipophilicity, membrane affinity, and protein binding without needing radiolabeled compounds or large sample amounts. Working within the Partnership for the Assessment of Risk from Chemicals, we profiled 67 neurotoxicology-relevant chemicals on immobilized artificial membrane, human serum albumin, and alpha-1-acid glycoprotein columns alongside lipophilicity measured at three pH values. The chromatographic lipophilicity scale matched literature log p values closely. Principal component and hierarchical cluster analyses of the seven descriptors pointed to one dominant hydrophobicity axis and a smaller, second axis tied to ionization and albumin binding. The panel’s overall chromatographic profile did not separate neurotoxic from non-neurotoxic reference compounds, but the most membrane- and protein-avid compounds were disproportionately positive controls and warrant closer attention. The resulting dataset gives New Approach Methodologies a ready, experimentally grounded input for in vitro-to-in vivo extrapolation and baseline toxicity assessment.

Background: ESKAPE constitutes a group of six nosocomial bacteria that can evade available antimicrobials due to their great potential to develop multi-drug resistance and biofilm-forming abilities. These pathogens often cause hospital-acquired infections and pose a serious threat to public health. The search for efficient innovative therapeutic strategies to fight ESKAPE bacteria have been intensively investigated topics. One promising approach to fight resistant pathogens and their biofilms is combination therapy, which allows the effectiveness against microorganisms to be increased while reducing the applied concentrations and risks of potential unwanted side effects. Objectives: The object of the study was to determine if there is an interaction of short lipopeptides ((C₁₀)₂-KKKK-NH₂, C₁₆-KK-NH₂) together with erythromycin and tetracycline against pathogens of the ESKAPE group (Acinetobacter baumannii, Enterobacter aerogenes, Enterococcus faecium Klebsiella pneumoniae, Pseudomonas aeruginosa, and Staphylococcus aureus). Methods: The checkerboard assay was used to examine the activity of compounds applied in combinations against ESKAPE strains in planktonic cells and toward biofilms formed by Staphylococcus aures and Pseudomonas aeruginosa. Results: The lipopeptides demonstrated a great potential of their application as additives to conventional antimicrobials against Gram-negative bacteria, including microorganisms within biofilms.

Human serum albumin (HSA) binding critically influences drug distribution and pharmacokinetics. In this study, HSA affinity chromatography was integrated with machine-learning-based quantitative structure–retention relationship (QSRR) modeling to elucidate structural determinants of albumin binding in a library of 115 fluoroquinolone (FQs) derivatives. Experimentally determined logk_HSA values were obtained using biomimetic chromatography, and these were then used as modelling endpoints. Following descriptor reduction via Least Absolute Shrinkage and Selection Operator (LASSO) and systematic benchmarking of 42 regression algorithms, support vector regression (SVR) and nu-support vector regression (ν-SVR) with radial basis function kernels demonstrated superior predictive performance. A parsimonious 12-descriptor ν-SVR model achieved strong calibration and validation metrics (R² = 0.916, Q²_test = 0.823, concordance correlation coefficient (CCC) = 0.899) and satisfied Organisation for Economic Co-operation and Development (OECD) criteria, including applicability domain assessment. Shapley Additive exPlanations (SHAP)-based interpretation revealed that albumin binding is governed by a balance between hydrophobic surface area and distributed electronic properties, whereas excessive localized polarity and quaternary ammonium functionalities reduce affinity. This experimentally anchored and interpretable modeling framework provides mechanistic insight into HSA binding in fluoroquinolones and offers a robust tool for rational pharmacokinetic optimization. Furthermore, in order to make the model easily accessible to users, we have packaged it in the form of an online application.

The aim of this study was to investigate which physicochemical and structural properties of cationic peptides P1–P6 may determine their selective anticancer activity against melanoma cells and their interactions with tumor cell membranes. An integrated approach was applied, including characterization in solution (osmotic pressure, NaCl stability, surface tension); cytotoxicity evaluation against Me45, B16F10, and HaCaT cells; analysis of interactions with phosphatidylglycerol (POPG) model membranes using isothermal titration calorimetry and steady-state fluorescence spectroscopy; membrane permeability assays; and F-actin staining. Anticancer activity depended on positively charged residues, hydrophobic amino acids, and sequence arrangement. Tryptophan-rich peptides P2 and P5 exhibited strong membrane interactions and high efficacy after 72 h. Highly hydrophobic P4, containing long C₁₂ chains with a relatively low net charge, caused nonselective lysis. P3 showed reduced activity due to insufficient amphipathicity, whereas P6, with excessive WWW and KKKK motifs, exhibited weak or nonselective effects. Thermodynamic and fluorescence analyses indicated that P2 and P5 initially bind POPG membranes via entropy-driven electrostatic interactions, followed by hydrophobic insertion of tryptophan residues, evidenced by increased fluorescence intensity and a blue shift of the emission maximum. P2, P4, and P5 induced actin cytoskeleton reorganization and increased membrane permeability, emphasizing the role of balanced amphipathicity and charge–hydrophobicity in designing selective anticancer peptides.

Background and purpose: Bisphenol A and its structural analogues are ubiquitous environmental contaminants and potential endocrine disruptors, creating a need for mechanistically relevant descriptors that support early hazard assessment. This study asked whether lipophilicity indices derived from biomimetic chromatography better reflect baseline toxicity and membrane-relevant behaviour of bisphenols than commonly used in silico log P / log D descriptors. Experimental approach: A set of 18 bisphenol derivatives was analysed using phosphatidylcholine- and sphingomyelin-functionalised stationary phases and a conventional C18 column to obtain chromatographic hydrophobicity indices, which were then compared with predicted log P / log D values and related to mechanistically diverse toxicity endpoints (in vitro cytotoxicity in mammalian cells, ex vivo cardiotoxicity assessed as vasodilation, and aquatic toxicity towards Daphnids). Key results: Biomimetic chromatographic indices showed consistently stronger and more coherent relationships with biological activity than theoretical descriptors. They also uniquely captured structural effects, such as positional isomerism, which were largely indistinguishable using theoretical lipophilicity indices. Conclusion: These findings support biomimetic chromatography as an early-tier IATA tool, providing membrane-relevant experimental indices linking bisphenol lipophilicity with baseline toxicity.

Rifampicin-resistant Mycobacterium tuberculosis (RR-TB) and methicillin-resistant Staphylococcus aureus (MRSA) underscore the need for new antibacterial chemotypes active across M. tuberculosis M. tuberculosis and Gram-positive pathogens. Both thiourea and tetrazole are well-established scaffolds in the scientific community for their promising antibacterial properties. The combination of tetrazole and thiourea moieties into a single molecular framework presents a promising strategy to overcome antimicrobial resistance. We designed and synthesized a series of tetrazole–thiourea derivatives (1–9) and a bis-tetrazole hybrid (10) through a one-step synthetic approach. Their antimicrobial potential was evaluated using a combination of in silico absorption, distribution, metabolism, excretion, and toxicity (ADMET) predictions, experimental lipophilicity determination (logD), and in vitro antibacterial assays against both reference and multidrug-resistant staphylococcal strains. Additionally, antitubercular activity was assessed against drug-sensitive, multidrug-resistant (MDR), and extensively drug-resistant (XDR) M. tuberculosis isolates. Molecular docking studies were performed to explore the binding interactions of the compounds with dihydrofolate reductase (DHFR) and penicillin-binding protein 4 (PBP4). Compound 2, bearing a trifluoromethyl substituent, was the most potent. It achieved sub-µg/mL minimum inhibitory concentrations (MICs, 0.1–0.5 µg/mL) against staphylococci, comparable to ciprofloxacin, and maintained strong antitubercular activity (MIC = 0.5 µg/mL) across drug-sensitive, MDR, and XDR strains. Docking supported a dual-target mechanism involving DHFR and PBP4, providing a plausible rationale for its broad antibacterial efficacy. Despite higher lipophilicity within the series, compound 2 showed favorable ADMET predictions and experimental logD values in the developable range. The tetrazole–thiourea scaffold, exemplified by compound 2, delivers dual efficacy against multidrug-resistant staphylococci and M. tuberculosis. These findings position compound 2 as a promising lead and a rational starting point for hit-to-lead optimization focused on potency–permeability balance and experimental confirmation of dual-target engagement. The online version contains supplementary material available at 10.1007/s43440-026-00848-4.

Triple-negative breast cancer (TNBC) remains one of the most aggressive breast cancer subtypes and is associated with limited therapeutic options, underscoring the urgent need for novel treatment strategies. In this study, a library of seventeen 1,3,5-triazine derivatives potentially targeting TNBC was developed using an activity-based approach. Compounds were synthesized via an ultrasound-assisted protocol, providing an efficient and environmentally friendly methodology. The synthesized library was evaluated in vitro against the human TNBC cell lines MDA-MB-468, MDA-MB-231, and Hs578T, as well as the non-tumorigenic epithelial cell line MCF10A. Compounds 9 and 17 exhibited the most promising antiproliferative activity against TNBC cell lines (MDA-MB-468: IC₅₀ = 36.62 µM for 9 and 38.29 µM for 17; MDA-MB-231: IC₅₀ = 37.32 µM for 9 and 32.86 µM for 17; Hs578T: IC₅₀ = 57.26 µM for 9 and 34.87 µM for 17), while maintaining acceptable selectivity toward non-cancerous cells. The lead compounds were further assessed in vivo using a Danio rerio model to evaluate general toxicity and cardiotoxicity. In addition, ADME parameters were predicted for all compounds using biomimetic chromatography. Overall, compounds 9 and 17 emerged as promising small-molecule candidates for TNBC treatment, requiring further toxicological evaluation in more human-relevant in vivo models.

Ascorbic acid (AA) and its derivatives (EAA), due to their antioxidant properties, may offer potential support in acne therapy. The aim of this study was to evaluate the effect of compound P6—(KK)₂-KWWW-NH₂—in the presence of AA or EAA on the stability and organization of phosphatidylinositol (PI) monolayers. The conducted experiments showed that the monolayers were in the expanded liquid state (37.45–48.35 mN/m) or in the transitional phase between the expanded liquid and condensed states (51.06–56.82 mN/m). Compression and decompression isotherms indicated the highest flexibility for the PI + P6 system, with the compression reversibility coefficient (R_v) ranging from 87.34% to 97.77%, increasing with temperature in successive loops. The surface pressure vs. time dependence after compound injection into the subphase revealed a decrease in monolayer surface pressure followed by stabilization after approximately 300 s for the PI + P6 + AA and PI + P6 + EAA systems. In contrast, for the PI + P6 system at 35 °C, an increase in surface pressure was observed.

Colorectal cancer (CRC) remains a major global health challenge, necessitating the development of more effective and environmentally sustainable treatments. This study presents a novel green synthetic protocol for 1,3,5-triazine derivatives with anticancer potential, employing both microwave-assisted and ultrasound-assisted methods. The synthesis was optimized using 4-chloro-N-(2-chlorophenyl)-6-(morpholin-4-yl)-1,3,5-triazin-2-amine as the key intermediate, with sodium carbonate, TBAB, and DMF providing optimal yields under microwave conditions. To enhance sustainability, a modified sonochemical method was also developed, enabling efficient synthesis in aqueous media with a minimal use of organic solvents. A series of nine morpholine-functionalized derivatives were synthesized and evaluated for cytotoxic activity against SW480 and SW620 colorectal cancer cell lines. Compound 11 demonstrated superior antiproliferative activity (IC₅₀ = 5.85 µM) compared to the reference drug 5-fluorouracil, while compound 5 showed promising dual-line activity. In silico ADME analysis supported the drug likeness of the synthesized compounds, and biomimetic chromatography analysis confirmed favorable physicochemical properties, including lipophilicity and membrane affinity. These results underscore the potential of the developed protocol to produce bioactive triazine derivatives through an efficient, scalable, and environmentally friendly process, offering a valuable strategy for future anticancer drug development.