Mattek at 2026 Eurotox Congress
Mattek scientists exhibit and present posters at the 2026 Eurotox Congress in Vienna, Austria.
Read on to see what we’ve been working on and download copies of our posters.
Attending the conference? Visit us at booth #48 to discuss your upcoming projects with our team.
Schedule a meeting with our teamPoster Presentations
Advancing Dermal Genotoxicity Assessment with RSMN and RSCOMET in Human 3D Skin Models (P14-46)
E. Reis1, M. Puskar1, Y. Kaluzhny2, P. Hayden2, J. DeLuca2, A. Armento2, V. Karetsky2, M. Klausner2, J. Markus1, S. Letasiova1
1MATTEK IVLSL, Now Part of Sartorius, Bratislava, Slovakia
2MATTEK, Now Part of Sartorius, Ashland, Massachusetts, United States of America
Session: PV01
Poster topic: P14 | Geno-toxicology & Carcinogenesis
Abstract
A 2025 peer review by EURL ECVAM confirmed the scientific validity of reconstructed skin micronucleus and Comet assays for the assessment of genotoxicity. In this context, we established complementary protocols using MatTek human 3D skin models, including EpiDerm™ for the reconstructed skin micronucleus assay (RSMN) and EpiDermFT™ for the reconstructed skin Comet assay (RSCOMET). These organotypic models provide route-relevant topical exposure together with tissue architecture, barrier properties, and skin-associated metabolic competence, thereby addressing important limitations of conventional 2D submerged systems.
RSMN detects chromosome damage through micronucleus formation in binucleated keratinocytes and is therefore suitable for identifying both clastogenic and aneugenic effects in reconstructed human epidermis. Our RSMN results showed statistically significant dose-dependent increases in cells containing micronuclei (MNC) for 9 direct genotoxins and 6 genotoxins requiring metabolic activation, while no increases were observed for 4 non-genotoxins. In parallel, RSCOMET enables the assessment of primary DNA damage in a full-thickness skin context. Similarly, Comet assay results showed statistically significant increases in % tail DNA following treatment with a model genotoxin.
Together, RSMN and RSCOMET provide complementary mechanistic information and broader biological coverage for the evaluation of dermal genotoxicity. Their combined use supports a more human-relevant, exposure-drive assessment of topically applied substances and formulations, may help clarify misleading positive findings generated in standard in vitro genotoxicity assays, and contributes to the transition toward animal-free testing strategies. Overall, these protocols represent a promising integrated platform for advancing genotoxicity assessment in reconstructed human skin tissues.
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Cutaneous In Vitro Wound Healing Model (P18-118)
M. Puskar1, M. Bachelor2, S. Letasiova1, J. Oldach2, G. Stolper2, M. Li2, A. Armento2, P. Hayden2
1 Mattek IVLSL now part of Sartorius, Bratislava, Slovakia
2 Mattek now part of Sartorius, Ashland, Massachusetts, United States of America
Session: PV01
Poster topic: P18 | In silico and in vitro methods
Abstract
Rapid and efficient epidermal wound healing is essential for maintaining normal skin barrier function. Interactions between fibroblasts and keratinocytes, as well as between cells and the extracellular matrix, play an important role in this process. Here we present wound healing model utilizing full-thickness in vitro human skin model (EpiDerm-FT). This model consists of normal human epidermal keratinocytes and normal human dermal fibroblasts cultured to form a multilayered model of the human dermis and epidermis. EpiDerm-FT has fully developed basement membrane, and it resembles in vivo skin in regard to morphology and barrier function. A model of wound healing was created by introducing wounds in epidermis using a 3-mm biopsy punch. Re-epithelization of the wound is evaluated by fixing the tissues, staining with hematoxylin and eosin, and by quantifying migration from the wound origin. Alternatively, wound closure can be visualized in situ by fixing and immunostaining the tissue with markers of epidermal differentiation as well as a marker of fibroblasts. This staining allows simultaneous visualization of migrating keratinocytes (keratin 14), differentiated suprabasal cells (involucrin), and dermal fibroblasts (vimentin) within the wound. Histological and immunohistochemical analysis showed keratinocyte migration at 2 days following wounding. In both methods, wounded tissues cultured without growth factors (2% human serum) had a reduced healing rate in which keratinocytes did not cover the entire wound within a 6-day time frame. In contrast, wounded tissues cultured with growth factors demonstrated increase in healing rate as keratinocyte migration completely covered the wounded area by day 6. In conclusion, the EpiDerm-FT model serves as a valuable tool for studying cutaneous wound healing. It is well-suited model for evaluating new therapeutic compounds designed to accelerate the healing process and restore tissue integrity and skin barrier function.
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Validation of Epi2SensA and evaluation of its integration into the 2-out-of-3 defined approach for skin sensitization (P32-03)
C. Pellevoisin1, K. Guntur1, C. Romero1, J. Stadnicki1, J. Markus2, T. Landry1, M. Klausner1
1 MATTEK, Now Part of Sartorius, Ashland, Massachusetts, United States of America
2 MATTEK IVLSL, Now Part of Sartorius, Bratislava, Slovakia
Session: PV02
Poster topic: P32-03| Skin sensitization or skin toxicity
Abstract
Since publication of “The Adverse Outcome Pathway (AOP) for Skin Sensitization Initiated by Covalent Binding to Proteins”1, several in vitro methods targeting key events (KEs) of this AOP have been validated and implemented in the OECD TG 442 series, to support global use of non-animal approaches for regulatory skin sensitization assessment. In 2024, EpiSensA, a reconstructed human epidermis (RhE)-based gene expression assay using 4 marker genes (ATF3, GCLM, DNAJB4, IL‑8), was validated and incorporated into OECD TG 442D2. Here we present Epi2SensA, a similar RhE-based assay using the EpiDerm model (MatTek). Epi2sensA was optimized for the EpiDerm model with specific acceptance criteria (≥60% tissue viability) and an optimized prediction model requiring at least two positive gene markers. The catch-up validation of Epi2SensA was performed in four laboratories with 20 chemicals, according to the OECD Performance Standards3. The data analysis demonstrated reliability (between and within reproductivity), and predictive performance (sensitivity, specificity and accuracy) comparable to the validated reference method (VRM) EpiSensA, supporting suitability of Epi2SensA for regulatory use4.
To further assess the impact of the adaptation of Epi2SensA prediction model to the EpiDerm model, an extended set of 47 chemicals (13 non‑sensitizers, 34 sensitizers) was evaluated. The results confirmed the excellent predictivity of the method, with 91.2% sensitivity, 92.3% specificity, and 91.5% accuracy. Performance for compounds considered difficult to test such as hydrophobic or pre/pro-hapten chemicals was also evaluated. The accuracy for classifying the 16 compounds with a logP≥3.5 was 87.5% and 8 pre/pro-hapten on a total of 9 were correctly classified as skin sensitizers. These results strengthen the evidence regarding the applicability of RhE-based methods to a broad chemical space, including compounds that are poorly compatible with aqueous culture media and/or that may require metabolic activity to exert their effects.
Finally, the relevance of Epi2SensA within integrated approaches to testing and assessment (IATA) was examined in the 2‑out‑of‑3 (2o3) defined approach of OECD TG 4975. Balanced accuracies were calculated for eight 2o3 permutations for the 47‑chemical dataset, combining Epi2SensA (KE2) with KE1 methods (ADRA, DPRA) and KE3 methods (GARD®skin, h‑CLAT, IL‑8 Luc, U‑SENS). The results demonstrate that Epi2SensA can be effectively integrated into established defined approaches, supporting human‑relevant, non‑animal strategies for skin sensitization risk assessment.
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Cross-Site Reproducibility and Discriminatory Performance of EpiVaginal Using ET-50 and Multi-Endpoint Readouts (P30-103)
J. Markus1, E. Reis1, K. Forro3, S. Letasiova1, T. Landry2, M. Klausner2, K. Coen2, K. Kejlova4, M. Dvorakova4, E. Pacalova4, S. Ayehunie2
1 Mattek IVLSL now part of Sartorius, Bratislava, Slovakia
2 Mattek now part of Sartorius, Ashland, Massachusetts, United States of America
3 Faculty of Medicine, Comenius University, Institute of Medical Biology, Genetics and Clinical Genetics, Bratislava, Slovakia
4 National Institute of Public Health, Centre of Toxicology and Health Safety, Prague, Czech Republic
Session: PV02
Poster topic: P30 | Risk Prediction and Assessment /Risk assessment using New Approach Methodologies
Abstract
EpiVaginal™ was developed by Mattek as a highly differentiated 3D human vaginal epithelium derived from normal ectocervical epithelial cells and proposed as an in vitro alternative to the Rabbit Vaginal Irritation (RVI) test. While produced for many years in USA, it was only recently introduced in Europe. This case study asked: (i) can new manufacturing site meet the same batch reproducibility standards as the long-established site, and (ii) once established, does the method transfer across laboratories while retaining the ability to distinguish irritant from non-irritant response profiles?
Manufacturing robustness was assessed using routine QC parameters, including ET-50 to 1% Triton X-100 (acceptance 0.70–1.70 h), average exposure CV (%), and histology, across 2024 U.S. lots (n=20) and 2024–2025 Europe lots (n=40). Method transferability was evaluated by running matched irritation testing (ET-50 and TEER) in-house and in a European partner laboratory using a shared panel of vaginal ingredients. To increase physiological relevance, selected ingredients were profiled internally with and without Simulated Vaginal Fluid (SVF) using ET-50, TEER, and inflammatory cytokines.
All 60 lots met ET-50 acceptance criteria with intra-lot dose–response variability <10%, supporting successful transfer of manufacturing robustness from the U.S. to Europe. Inter-laboratory testing showed strong concordance (mean differences 7.2% for viability and 6.4% for %TEER) and consistent classification of irritants versus non-irritants across sites. In SVF-conditioned studies, response patterns suggested attenuation of acidity-driven injury for selected ingredients, whereas surfactant-type injury remained largely unchanged; cytokine profiles were consistent with previously published patterns.
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Studying Intestinal Inflammation and Drug Response in 3D Reconstructed Intestinal Epithelium Model (P30-105)
K. Forró1, S. Letasiova2, S. Ayehunie3, J. Kronek4, Z. Kronekova2, J. Markus2
1 Faculty of Medicine, Comenius University, Institute of Medical Biology, Genetics and Clinical Genetics, Bratislava, Slovakia
2 Mattek IVLSL now part of Sartorius, Bratislava, Slovakia
3 Mattek now part of Sartorius, Ashland, Massachusetts, United States of America
4 Slovak Academy of Sciences, Dept. of Biomaterials Research, Polymer Institute, Bratislava, Slovakia
Session: PV02
Poster topic: P30 | Risk Prediction and Assessment /Risk assessment using New Approach Methodologies
Abstract
In vitro reconstructed 3D human small intestine epithelium model EpiIntestinal is a valuable tool for studying intestinal physiology, including barrier integrity, drug kinetics, and interactions with pathogens. It has also been shown to recapitulate innate immune responses and responds to stimulation with pro inflammatory cytokines (e.g., TNFα, IFNγ). This study aimed to (I) investigate factors affecting the inflammatory response and (II) explore the suitability of EpiIntestinal for predicting the efficacy and safety of anti-inflammatory drugs.
Tissues were produced as previously described (1), and inflammation was induced by the addition of TNFα and IFNγ under various cultivation conditions (presence of human serum, serum-free medium, or in the presence of TNFα signaling inhibitors). The inflammatory response was evaluated by measuring barrier integrity (trans-epithelial electrical resistance, TEER), cytokine release (ELISA), analysis of tissue viability and morphology. In subsequent experiments, tissues were exposed to selected anti-inflammatory drugs in the presence or absence of inflammatory stimuli. The effects of these drugs on barrier integrity, morphology, viability, and inflammatory response were investigated.
(I) We showed that the inflammatory response was much more consistent under serum-free conditions than in the presence of serum, which introduced variability in baseline levels of several cytokines, including IL-6 and IL-8, and in barrier integrity. This variability was not reduced by the addition of TNF inhibitors to serum-containing medium. Both the inflammation-associated decline in barrier integrity and the cytokine response were more pronounced in serum-free conditions. (II) In experiments evaluating safety and efficacy, tissues were first exposed to ibuprofen at various concentrations.
While the tissues tolerated standard clinical concentrations of the drug, they showed a rapid, irreversible decline in barrier integrity after prolonged exposure to higher concentrations. This was accompanied by morphological changes and loss of viability. In contrast, when the same amount of drug was bound to a carrier polymer (poly(2-isopropenyl-2-oxazoline), PIPOx), a promising platform for biomedical applications, no detrimental effects on the tissues were observed. Ongoing experiments aim to investigate additional drugs in both free and carrier-bound forms. Their effects on tissue condition and inflammatory processes will be reported.
Our findings emphasize that microenvironmental factors, such as serum-derived components, can significantly alter the outcomes of in vitro experiments. Careful consideration of these parameters is essential for accurate interpretation of data and for improving the translational relevance of organotypic models in safety assessment. Our results suggest that EpiIntestinal may become a useful tool for the comprehensive evaluation of the activity and safety of (potential) anti-inflammatory compounds in vitro.
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