{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,17]],"date-time":"2026-03-17T18:06:30Z","timestamp":1773770790056,"version":"3.50.1"},"reference-count":41,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2026,3,17]],"date-time":"2026-03-17T00:00:00Z","timestamp":1773705600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"European Union\u2019s Horizon 2020 research and innovation program","award":["723951"],"award-info":[{"award-number":["723951"]}]},{"DOI":"10.13039\/100000181","name":"Air Force Office of Scientific Research","doi-asserted-by":"publisher","award":["FA8655-20-1-7021"],"award-info":[{"award-number":["FA8655-20-1-7021"]}],"id":[{"id":"10.13039\/100000181","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Engineering and Physical Sciences Research Council (EPSRC) Cambridge Nano-science and Nanotechnology (NanoDTC) Ph.D. studentship","award":["EP\/S022953\/1"],"award-info":[{"award-number":["EP\/S022953\/1"]}]},{"name":"EPSRC studentship","award":["EP\/T517847\/1"],"award-info":[{"award-number":["EP\/T517847\/1"]}]},{"name":"Sensors CDT funding by the Engineering and Physical Sciences Research Council Centre for Doctoral Training in Sensor Technologies and Applications","award":["EP\/L015889\/1"],"award-info":[{"award-number":["EP\/L015889\/1"]}]},{"name":"W.D. Armstrong studentship at the University of Cambridge"},{"name":"European Union\u2019s Horizon 2020 research and innovation program under Marie Sk\u0142odowska-Curie grant agreements","award":["842356"],"award-info":[{"award-number":["842356"]}]},{"name":"European Union\u2019s Horizon 2020 research and innovation program under Marie Sk\u0142odowska-Curie grant agreements","award":["895801"],"award-info":[{"award-number":["895801"]}]},{"name":"Henry Royce Institute for Advanced Materials through the Equipment Access Scheme"},{"name":"Cambridge Royce facilities grant","award":["EP\/P024947\/1"],"award-info":[{"award-number":["EP\/P024947\/1"]}]},{"name":"Sir Henry Royce Institute\u2014recurrent grant","award":["EP\/R00661X\/1"],"award-info":[{"award-number":["EP\/R00661X\/1"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Bioengineering"],"abstract":"<jats:p>Physiologically relevant in vitro intestinal models are essential for studying key physiological processes, including barrier function, drug screening and gut-microbiota interactions. However, conventional 2D culture systems often fail to recapitulate structural and functional complexity. Here, we aimed to validate a 3D bioelectronic transmembrane platform, previously used for monitoring human intestinal epithelium and vascular endothelium, for modeling the rat small intestinal barrier in vitro. The device integrates a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) scaffold supporting co-cultures of rat intestinal epithelial cells (IEC-6) and rat fibroblasts (208F), enabling real-time monitoring of barrier formation through electrical measurements using electrochemical impedance spectroscopy (EIS). Barrier formation was monitored over 21 days and exhibited a time-dependent increase in barrier resistance. The 3D platform was compared with traditional 2D insert-based cultures and ex vivo rat tissue using an Ethylene Glycol Tetraacetic Acid (EGTA)-induced calcium switch assay to evaluate barrier disruption and recovery. EGTA treatment and removal induced reversible barrier disruption in the 3D in vitro and ex vivo models, whereas 2D in vitro cultures showed limited recovery. These findings demonstrate that the 3D platform more faithfully recapitulates native tissue architecture and function, closely paralleling ex vivo responses. Our study highlights the importance of validating advanced 3D in vitro models and establishes this bioelectronic platform as a robust tool for drug screening, barrier studies, and preclinical gastrointestinal research.<\/jats:p>","DOI":"10.3390\/bioengineering13030349","type":"journal-article","created":{"date-parts":[[2026,3,17]],"date-time":"2026-03-17T14:50:48Z","timestamp":1773759048000},"page":"349","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Comparison of 2D, 3D In Vitro, and Ex Vivo Platforms for Modeling the Rat Small Intestine"],"prefix":"10.3390","volume":"13","author":[{"given":"Shani","family":"Elias-Kirma","sequence":"first","affiliation":[{"name":"Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9086-7019","authenticated-orcid":false,"given":"Reece","family":"McCoy","sequence":"additional","affiliation":[{"name":"Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Douglas van","family":"Niekerk","sequence":"additional","affiliation":[{"name":"Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Verena","family":"Stoeger","sequence":"additional","affiliation":[{"name":"Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sophie","family":"Oldroyd","sequence":"additional","affiliation":[{"name":"Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Emma","family":"Sumner","sequence":"additional","affiliation":[{"name":"Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Achilleas","family":"Savva","sequence":"additional","affiliation":[{"name":"Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, UK"},{"name":"Department of Microelectronics, Faculty of Electrical Engineering, Mathematics and Computer Science, Delft University of Technology, Mekelweg 4, 2628 CD Delft, The Netherlands"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7856-2108","authenticated-orcid":false,"given":"R\u00f3is\u00edn M.","family":"Owens","sequence":"additional","affiliation":[{"name":"Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,3,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Galvan, A., Guidorizzi, E., Carton, F., and Malatesta, M. (2025). In vitro and ex vivo models to study molecular trafficking across the human intestinal barrier. Int. J. Mol. Sci., 26.","DOI":"10.3390\/ijms262110535"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Di Tommaso, N., Gasbarrini, A., and Ponziani, F.R. (2021). Intestinal barrier in human health and disease. Int. J. Env. Res. Public Health, 18.","DOI":"10.3390\/ijerph182312836"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"149","DOI":"10.1007\/s00018-017-2693-8","article-title":"Mouse models for human intestinal microbiota research: A critical evaluation","volume":"75","author":"Hugenholtz","year":"2018","journal-title":"Cell. Mol. Life Sci."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"103","DOI":"10.1038\/s12276-018-0126-x","article-title":"Mechanisms regulating intestinal barrier integrity and its pathological implications","volume":"50","author":"Chelakkot","year":"2018","journal-title":"Exp. Mol. Med."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"138","DOI":"10.1016\/j.jcmgh.2016.11.007","article-title":"Gastrointestinal organoids: Understanding the molecular basis of the host\u2013microbe interface","volume":"3","author":"Hill","year":"2017","journal-title":"Cell. Mol. Gastroenterol. Hepatol."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Rahman, S., Ghiboub, M., Donkers, J.M., van de Steeg, E., van Tol, E.A., Hakvoort, T.B., and de Jonge, W.J. (2021). The progress of intestinal epithelial models from cell lines to gut-on-chip. Int. J. Mol. Sci., 22.","DOI":"10.3390\/ijms222413472"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"e2306727","DOI":"10.1002\/advs.202306727","article-title":"In vitro models for investigating intestinal host\u2013pathogen interactions","volume":"11","author":"McCoy","year":"2024","journal-title":"Adv. Sci."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"63","DOI":"10.1211\/jpp.60.1.0008","article-title":"Measurements of rat and mouse gastrointestinal pH, fluid and lymphoid tissue, and implications for in vivo experiments","volume":"60","author":"McConnell","year":"2008","journal-title":"J. Pharm. Pharmacol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1997296","DOI":"10.1080\/19490976.2021.1997296","article-title":"Gut microbiota\u2013motility interregulation: Insights from in vivo, ex vivo and in silico studies","volume":"14","author":"Codutti","year":"2022","journal-title":"Gut Microbes"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1186\/s41231-019-0050-7","article-title":"Lost in translation: The valley of death across preclinical and clinical divide\u2014Identification of problems and overcoming obstacles","volume":"4","author":"Seyhan","year":"2019","journal-title":"Transl. Med. Commun."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"154","DOI":"10.1038\/s43856-022-00209-1","article-title":"Performance assessment and economic analysis of a human Liver-Chip for predictive toxicology","volume":"2","author":"Ewart","year":"2022","journal-title":"Commun. Med."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Han, X.M., Han, Y., Zheng, Y.S., Sun, Q., Ma, T., Zhang, J.Y., and Xu, L.J. (2017). Can animal models of disease reliably inform human studies?. PLoS ONE, 12.","DOI":"10.1371\/journal.pone.0175950"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"3507","DOI":"10.1073\/pnas.1222878110","article-title":"Genomic responses in mouse models poorly mimic human inflammatory diseases","volume":"110","author":"Seok","year":"2013","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Roodsant, T., Navis, M., Aknouch, I., Renes, I.B., van Elburg, R.M., Pajkrt, D., Wolthers, K.C., Schultsz, C., van der Ark, K.C.H., and Sridhar, A. (2020). A human 2D primary organoid-derived epithelial monolayer model to study host\u2013pathogen interaction in the small intestine. Front. Cell. Infect. Microbiol., 10.","DOI":"10.3389\/fcimb.2020.00272"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"262","DOI":"10.1038\/nature07935","article-title":"Single Lgr5 stem cells build crypt-villus structures in vitro without a mesenchymal niche","volume":"459","author":"Sato","year":"2009","journal-title":"Nature"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1130","DOI":"10.1039\/c3ib40126j","article-title":"Gut-on-a-chip microenvironment induces human intestinal cells to undergo villus differentiation","volume":"5","author":"Kim","year":"2013","journal-title":"Integr. Biol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"659","DOI":"10.1016\/j.jcmgh.2017.12.010","article-title":"Microfluidic organ-on-a-chip models of human intestine","volume":"5","author":"Bein","year":"2018","journal-title":"Cell. Mol. Gastroenterol. Hepatol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"eabm6493","DOI":"10.1126\/sciadv.abo4761","article-title":"Organic electronic transmembrane device for hosting and monitoring 3D cell cultures","volume":"8","author":"Pitsalidis","year":"2022","journal-title":"Sci. Adv."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"2300158","DOI":"10.1002\/smsc.202300349","article-title":"Modelling human gut\u2013microbiome interactions in a 3D bioelectronic platform","volume":"4","author":"Moysidou","year":"2024","journal-title":"Small Sci."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"3589","DOI":"10.1039\/D3MH00785E","article-title":"3D organic bioelectronics for electrical monitoring of human adult stem cells","volume":"10","author":"Savva","year":"2023","journal-title":"Mater. Horiz."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"e00409","DOI":"10.1002\/adbi.202500409","article-title":"Bioelectronic technology for nutritional research\u2014A novel in vitro platform for a better understanding of human gut barrier absorption","volume":"10","author":"Stoeger","year":"2026","journal-title":"Adv. Biol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"85","DOI":"10.1186\/s13287-024-03685-5","article-title":"Functional intestinal monolayers from organoids derived from human iPS cells for drug discovery research","volume":"15","author":"Inui","year":"2024","journal-title":"Stem Cell Res. Ther."},{"key":"ref_23","first-page":"362","article-title":"Sequential construction of vascularized and mineralized bone organoids using engineered ECM-DNA-CPO-based bionic matrix for efficient bone regeneration","volume":"49","author":"Gai","year":"2025","journal-title":"Bioact. Mater."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"82","DOI":"10.36922\/or.8294","article-title":"Nerve\u2013bone crosstalk manipulates bone organoid development and bone regeneration: A review and perspectives","volume":"1","author":"Song","year":"2025","journal-title":"Organoid Res."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"91","DOI":"10.1016\/j.actbio.2017.08.045","article-title":"Highly porous scaffolds of PEDOT:PSS for bone tissue engineering","volume":"62","author":"Guex","year":"2017","journal-title":"Acta Biomater."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"2200941","DOI":"10.1002\/adhm.202200941","article-title":"Conducting polymer-ECM scaffolds for human neuronal cell differentiation","volume":"11","author":"Barberio","year":"2022","journal-title":"Adv. Healthc. Mater."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"266","DOI":"10.1016\/j.ijbiomac.2022.10.122","article-title":"Electroconductive scaffolds based on gelatin and PEDOT:PSS for cardiac regeneration","volume":"224","author":"Furlani","year":"2023","journal-title":"Int. J. Biol. Macromol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"eaat4253","DOI":"10.1126\/sciadv.aat4253","article-title":"Transistor in a tube: A route to three-dimensional bioelectronics","volume":"4","author":"Pitsalidis","year":"2018","journal-title":"Sci. Adv."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Moysidou, C.M., Barberio, C., and Owens, R.M. (2021). Advances in engineering human tissue models. Front. Bioeng. Biotechnol., 8.","DOI":"10.3389\/fbioe.2020.620962"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"326","DOI":"10.1039\/D1LC00669J","article-title":"Intestinal explant barrier chip: Long-term intestinal absorption screening in a novel microphysiological system using tissue explants","volume":"22","author":"Donkers","year":"2022","journal-title":"Lab A Chip"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1070","DOI":"10.1021\/js960110x","article-title":"HT29-MTX\/Caco-2 cocultures as an in vitro model for the intestinal epithelium: In vitro-in vivo correlation with permeability data from rats and humans","volume":"85","author":"Walter","year":"1996","journal-title":"J. Pharm. Sci."},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Pearce, S.C., Coia, H.G., Karl, J.P., Pantoja-Feliciano, I.G., Zachos, N.C., and Racicot, K. (2018). Intestinal in vitro and ex vivo models to study host-microbiome interactions and acute stressors. Front. Physiol., 9.","DOI":"10.3389\/fphys.2018.01584"},{"key":"ref_33","first-page":"17","article-title":"Closed-loop Doluisio (colon, small intestine) and single-pass intestinal perfusion (colon, jejunum) in rat\u2014Biophysical model and predictions based on Caco-2","volume":"35","author":"Zur","year":"2018","journal-title":"Pharm. Res."},{"key":"ref_34","first-page":"114","article-title":"Ussing chamber: The study of transepithelial transport in the small intestine","volume":"33","author":"Matei","year":"2023","journal-title":"Rev. Rom. Med. Vet."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"27249","DOI":"10.1039\/D0RA04162A","article-title":"Barrier-promoting efficiency of two bioactive flavonols quercetin and myricetin on rat intestinal epithelial (IEC-6) cells via suppressing Rho activation","volume":"10","author":"Fan","year":"2020","journal-title":"RSC Adv."},{"key":"ref_36","first-page":"5121","article-title":"DIM attenuates TGF-\u03b21-induced myofibroblast differentiation in neonatal rat cardiac fibroblasts","volume":"8","author":"Li","year":"2015","journal-title":"Int. J. Clin. Exp. Pathol."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"10453","DOI":"10.1128\/JVI.01631-15","article-title":"Role for a Zinc Finger Protein (Zfp111) in Transformation of 208F Rat Fibroblasts by Jaagsiekte Sheep Retrovirus Envelope Protein","volume":"89","author":"Hsu","year":"2015","journal-title":"J. Virol."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"e45","DOI":"10.1093\/nar\/gkp045","article-title":"Amplification efficiency: Linking baseline and bias in the analysis of quantitative PCR data","volume":"37","author":"Ruijter","year":"2009","journal-title":"Nucleic Acids Res."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"117157","DOI":"10.1016\/j.synthmet.2022.117157","article-title":"Hydrophilic, conductive and flexible piezoresistive PEDOT:PSS 3D sensors with tunable microarchitecture and crosslinked using a PEGylated crosslinker","volume":"290","author":"Solazzo","year":"2022","journal-title":"Synth. Met."},{"key":"ref_40","first-page":"G345","article-title":"Leukotriene D4 requires PKC\u03b1\u2013Akt signaling pathway to inhibit Na+-dependent alanine cotransporter (ASCT1) in enterocytes","volume":"310","author":"Talukder","year":"2016","journal-title":"J. Gastrointest. Dig. Syst."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"2041731414557112","DOI":"10.1177\/2041731414557112","article-title":"The extracellular matrix: Structure, composition, age-related differences, tools for analysis and applications for tissue engineering","volume":"5","author":"Kular","year":"2014","journal-title":"J. Tissue Eng."}],"container-title":["Bioengineering"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2306-5354\/13\/3\/349\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,3,17]],"date-time":"2026-03-17T14:56:41Z","timestamp":1773759401000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2306-5354\/13\/3\/349"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,3,17]]},"references-count":41,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2026,3]]}},"alternative-id":["bioengineering13030349"],"URL":"https:\/\/doi.org\/10.3390\/bioengineering13030349","relation":{},"ISSN":["2306-5354"],"issn-type":[{"value":"2306-5354","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,3,17]]}}}