{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,13]],"date-time":"2026-09-13T05:43:08Z","timestamp":1789278188705,"version":"build-2803163510"},"reference-count":42,"publisher":"American Chemical Society (ACS)","issue":"22","license":[{"start":{"date-parts":[[2018,10,16]],"date-time":"2018-10-16T00:00:00Z","timestamp":1539648000000},"content-version":"stm-asf","delay-in-days":0,"URL":"https:\/\/doi.org\/10.15223\/policy-029"},{"start":{"date-parts":[[2018,10,16]],"date-time":"2018-10-16T00:00:00Z","timestamp":1539648000000},"content-version":"stm-asf","delay-in-days":0,"URL":"https:\/\/doi.org\/10.15223\/policy-037"},{"start":{"date-parts":[[2018,10,16]],"date-time":"2018-10-16T00:00:00Z","timestamp":1539648000000},"content-version":"stm-asf","delay-in-days":0,"URL":"https:\/\/doi.org\/10.15223\/policy-045"}],"funder":[{"DOI":"10.13039\/100000062","name":"National Institute of Diabetes and Digestive and Kidney Diseases","doi-asserted-by":"publisher","award":["DK109559"],"award-info":[{"award-number":["DK109559"]}],"id":[{"id":"10.13039\/100000062","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2018,11,20]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Animal models are frequently used for in vitro physiologic and drug transport studies of the colon, but there exists significant pressure to improve assay throughput as well as to achieve tighter control of experimental variables than can be achieved with animals. Thus, development of a primary in vitro colonic epithelium cultured as high resistance with transport protein expression and functional behavior similar to that of a native colonic would be of enormous value for pharmaceutical research. A collagen scaffold, in which the degree of collagen cross-linking was present as a gradient, was developed to support the proliferation of primary colonic cells. The gradient of cross-linking created a gradient in stiffness across the scaffold, enabling the scaffold to resist deformation by cells. mRNA expression and quantitative proteomic mass spectrometry of cells growing on these surfaces as a monolayer suggested that the transporters present were similar to those in vivo. Confluent monolayers acted as a barrier to small molecules so that drug transport studies were readily performed. Transport function was evaluated using atenolol (a substrate for passive paracellular transport), propranolol (a substrate for passive transcellular transport), rhodamine 123 (Rh123, a substrate for P-glycoprotein), and riboflavin (a substrate for solute carrier transporters). Atenolol was poorly transported with an apparent permeability (Papp) of &amp;lt;5 \u00d7 10\u20137 cm s\u20131, while propranolol demonstrated a Papp of 9.69 \u00d7 10\u20136 cm s\u20131. Rh123 was transported in a luminal direction (Papp,efflux\/Papp,influx = 7) and was blocked by verapamil, a known inhibitor of P-glycoprotein. Riboflavin was transported in a basal direction, and saturation of the transporter was observed at high riboflavin concentrations as occurs in vivo. It is anticipated that this platform of primary colonic epithelium will find utility in drug development and physiological studies, since the tissue possesses high integrity and active transporters and metabolism similar to that in vivo.<\/jats:p>","DOI":"10.1021\/acs.analchem.8b02845","type":"journal-article","created":{"date-parts":[[2018,10,16]],"date-time":"2018-10-16T15:02:40Z","timestamp":1539702160000},"page":"13331-13340","source":"Crossref","is-referenced-by-count":36,"title":["A Monolayer of Primary Colonic Epithelium Generated\non a Scaffold with a Gradient of Stiffness for Drug Transport Studies"],"prefix":"10.1021","volume":"90","author":[{"given":"Dulan\nB.","family":"Gunasekara","sequence":"first","affiliation":[{"name":"University of North Carolina at Chapel Hill , , , ,","place":["Chapel Hill, North Carolina, United States, 27599"]},{"name":"Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States and North Carolina State University, Raleigh, North Carolina 27607, United States"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jennifer","family":"Speer","sequence":"additional","affiliation":[{"name":"University of North Carolina at Chapel Hill , , , ,","place":["Chapel Hill, North Carolina, United States, 27599"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yuli","family":"Wang","sequence":"additional","affiliation":[{"name":"University of North Carolina at Chapel Hill , , , ,","place":["Chapel Hill, North Carolina, United States, 27599"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Daniel L.","family":"Nguyen","sequence":"additional","affiliation":[{"name":"University of North Carolina at Chapel Hill , , , ,","place":["Chapel Hill, North Carolina, United States, 27599"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mark I.","family":"Reed","sequence":"additional","affiliation":[{"name":"University of North Carolina at Chapel Hill , , , ,","place":["Chapel Hill, North Carolina, United States, 27599"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nicole M.","family":"Smiddy","sequence":"additional","affiliation":[{"name":"University of North Carolina at Chapel Hill , , , ,","place":["Chapel Hill, North Carolina, United States, 27599"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Joel S.","family":"Parker","sequence":"additional","affiliation":[{"name":"University of North Carolina at Chapel Hill and , , , ,","place":["Chapel Hill, North Carolina, United States, 27514"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1848-0121","authenticated-orcid":true,"given":"John K.","family":"Fallon","sequence":"additional","affiliation":[{"name":"University of North Carolina at Chapel Hill , , , ,","place":["Chapel Hill, North Carolina, United States, 27599"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Philip C.","family":"Smith","sequence":"additional","affiliation":[{"name":"University of North Carolina at Chapel Hill , , , ,","place":["Chapel Hill, North Carolina, United States, 27599"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Christopher E.","family":"Sims","sequence":"additional","affiliation":[{"name":"University of North Carolina at Chapel Hill , , , ,","place":["Chapel Hill, North Carolina, United States, 27599"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Scott T.","family":"Magness","sequence":"additional","affiliation":[{"name":"Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States and North Carolina State University, Raleigh, North Carolina 27607, United States"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9242-768X","authenticated-orcid":true,"given":"Nancy L.","family":"Allbritton","sequence":"additional","affiliation":[{"name":"University of North Carolina at Chapel Hill , , , ,","place":["Chapel Hill, North Carolina, United States, 27599"]},{"name":"Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States and North Carolina State University, Raleigh, North Carolina 27607, United States"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"316","published-online":{"date-parts":[[2018,10,16]]},"reference":[{"key":"2026081502121207200_cit1","doi-asserted-by":"publisher","first-page":"60","DOI":"10.1021\/mp800261a","article-title":"Toward an\nIncreased Understanding of the Barriers to Colonic Drug Absorption\nin Humans: Implications for Early Controlled Release Candidate Assessment","volume":"6","author":"Tannergren","year":"2009","journal-title":"Mol. Pharmaceutics"},{"key":"2026081502121207200_cit2","doi-asserted-by":"publisher","first-page":"25","DOI":"10.1016\/j.ejps.2003.07.003","article-title":"The ABCs of Drug Transport in Intestine\nand Liver: Efflux Proteins Limiting Drug Absorption and Bioavailability","volume":"21","author":"Chan","year":"2004","journal-title":"Eur. J. Pharm. Sci."},{"key":"2026081502121207200_cit3","doi-asserted-by":"publisher","first-page":"109","DOI":"10.2174\/1389200043489144","article-title":"Intestinal Drug Transporters: In\nVivo Function and\nClinical Importance","volume":"5","author":"Kunta","year":"2004","journal-title":"Curr. Drug Metab."},{"key":"2026081502121207200_cit4","doi-asserted-by":"publisher","first-page":"52","DOI":"10.1038\/clpt.2013.74","article-title":"Emerging Transporters\nof Clinical Importance: An Update from the International Transporter\nConsortium","volume":"94","author":"Hillgren","year":"2013","journal-title":"Clin. Pharmacol. Ther."},{"key":"2026081502121207200_cit5","doi-asserted-by":"publisher","first-page":"543","DOI":"10.1038\/nrd4626","article-title":"SLC Transporters\nas Therapeutic Targets: Emerging Opportunities","volume":"14","author":"Lin","year":"2015","journal-title":"Nat. Rev. Drug Discovery"},{"key":"2026081502121207200_cit6","first-page":"1","article-title":"Membrane Transporters: Fundamentals,\nFunction and Their Role in ADME","volume-title":"Drug Transporters:\nVol. 1: Role and Importance in ADME and Drug Development","author":"Keogh","year":"2016"},{"key":"2026081502121207200_cit7","doi-asserted-by":"publisher","first-page":"215","DOI":"10.1038\/nrd3028","article-title":"Membrane Transporters in Drug Development","volume":"9","author":"Giacomini","year":"2010","journal-title":"Nat. Rev. Drug Discovery"},{"key":"2026081502121207200_cit8","doi-asserted-by":"publisher","first-page":"G1151","DOI":"10.1152\/ajpgi.90649.2008","article-title":"A Guide\nto Ussing Chamber Studies of Mouse Intestine","volume":"296","author":"Clarke","year":"2009","journal-title":"Am. J. Physiol. - Gastrointest. Liver Physiol."},{"key":"2026081502121207200_cit9","doi-asserted-by":"publisher","first-page":"190","DOI":"10.1186\/1471-2164-15-190","article-title":"Immunomic,\nGenomic and Transcriptomic Characterization\nof CT26 Colorectal Carcinoma","volume":"15","author":"Castle","year":"2014","journal-title":"BMC Genomics"},{"key":"2026081502121207200_cit10","doi-asserted-by":"publisher","first-page":"395","DOI":"10.1517\/17425255.4.4.395","article-title":"The Caco-2\nCell Monolayer: Usefulness and Limitations","volume":"4","author":"Sun","year":"2008","journal-title":"Expert Opin. Drug Metab. Toxicol."},{"key":"2026081502121207200_cit11","doi-asserted-by":"publisher","first-page":"1762","DOI":"10.1053\/j.gastro.2011.07.050","article-title":"Long-Term\nExpansion of Epithelial Organoids From Human Colon, Adenoma, Adenocarcinoma,\nand Barrett\u2019s Epithelium","volume":"141","author":"Sato","year":"2011","journal-title":"Gastroenterology"},{"key":"2026081502121207200_cit12","doi-asserted-by":"publisher","first-page":"238","DOI":"10.1016\/j.bbrc.2012.01.155","article-title":"Real-Time Analysis of\nP-Glycoprotein-Mediated\nDrug Transport across Primary Intestinal Epithelium Three-Dimensionally\nCultured in Vitro","volume":"419","author":"Mizutani","year":"2012","journal-title":"Biochem. Biophys. Res. Commun."},{"key":"2026081502121207200_cit13","doi-asserted-by":"publisher","first-page":"939","DOI":"10.1038\/nm.3201","article-title":"A Functional\nCFTR Assay Using Primary Cystic Fibrosis Intestinal Organoids","volume":"19","author":"Dekkers","year":"2013","journal-title":"Nat. Med."},{"key":"2026081502121207200_cit14","doi-asserted-by":"publisher","first-page":"818","DOI":"10.1038\/mi.2013.98","article-title":"Development\nof a Primary Mouse Intestinal Epithelial Cell Monolayer Culture System\nto Evaluate Factors That Modulate IgA Transcytosis","volume":"7","author":"Moon","year":"2014","journal-title":"Mucosal Immunol."},{"key":"2026081502121207200_cit15","doi-asserted-by":"publisher","first-page":"165","DOI":"10.1016\/j.jcmgh.2017.02.011","article-title":"Self-Renewing Monolayer of Primary Colonic\nor Rectal Epithelial Cells","volume":"4","author":"Wang","year":"2017","journal-title":"Cell. Mol. Gastroenterol.\nHepatol."},{"key":"2026081502121207200_cit16","doi-asserted-by":"publisher","first-page":"G590","DOI":"10.1152\/ajpgi.00470.2009","article-title":"Sox9 Expression Marks a Subset of\nCD24-Expressing Small Intestine Epithelial Stem Cells That Form Organoids\nin Vitro","volume":"298","author":"Gracz","year":"2010","journal-title":"AJP Gastrointest. Liver Physiol."},{"key":"2026081502121207200_cit17","doi-asserted-by":"publisher","first-page":"2111","DOI":"10.1038\/nprot.2007.303","article-title":"Determination of Drug Permeability\nand Prediction of Drug Absorption in Caco-2 Monolayers","volume":"2","author":"Hubatsch","year":"2007","journal-title":"Nat. Protoc."},{"key":"2026081502121207200_cit18","doi-asserted-by":"publisher","first-page":"3017","DOI":"10.1093\/bioinformatics\/bti448","article-title":"False Discovery\nRate, Sensitivity and Sample Size for Microarray Studies","volume":"21","author":"Pawitan","year":"2005","journal-title":"Bioinformatics"},{"key":"2026081502121207200_cit19","doi-asserted-by":"publisher","first-page":"4402","DOI":"10.1021\/pr4004213","article-title":"Targeted\nQuantitative Proteomics for the Analysis of 14 UGT1As and-2Bs in Human\nLiver Using NanoUPLC\u2013MS\/MS with Selected Reaction Monitoring","volume":"12","author":"Fallon","year":"2013","journal-title":"J. Proteome Res."},{"key":"2026081502121207200_cit20","unstructured":"Kailasam, S.; Frost, K.\n          Rapid Method Development To Study\nPlasma Stability of Diverse Pharmaceutical Compounds Using Rapid Resolution\nLC and Triple Quadrupole MS; Publication Number 5990-4603EN; Agilent Technologies, 2009; https:\/\/www.agilent.com\/cs\/library\/applications\/5990-4603EN.pdf."},{"key":"2026081502121207200_cit21","doi-asserted-by":"publisher","first-page":"550","DOI":"10.1186\/s13059-014-0550-8","article-title":"Moderated\nEstimation of Fold Change\nand Dispersion for RNA-Seq Data with DESeq2","volume":"15","author":"Love","year":"2014","journal-title":"Genome Biol."},{"key":"2026081502121207200_cit22","doi-asserted-by":"crossref","first-page":"289","DOI":"10.1111\/j.2517-6161.1995.tb02031.x","article-title":"Controlling the False\nDiscovery Rate: A Practical and\nPowerful Approach to Multiple Testing","volume":"57","author":"Benjamini","year":"1995","journal-title":"J. R.\nStat. Soc. Ser. B Methodol."},{"key":"2026081502121207200_cit23","volume-title":"Biophysical Chemistry:\nPart III: The Behavior of Biological Macromolecules","author":"Cantor","year":"1980"},{"key":"2026081502121207200_cit24","doi-asserted-by":"publisher","first-page":"225","DOI":"10.4251\/wjgo.v6.i7.225","article-title":"Novel Diet-Related\nMouse Model of Colon Cancer Parallels Human Colon Cancer","volume":"6","author":"Prasad","year":"2014","journal-title":"World J. Gastrointest. Oncol."},{"key":"2026081502121207200_cit25","doi-asserted-by":"publisher","first-page":"E1380","DOI":"10.1073\/pnas.1218446110","article-title":"Enterocyte Loss of Polarity\nand Gut Wound Healing Rely upon the F-Actin-Severing Function of Villin","volume":"110","author":"Ubelmann","year":"2013","journal-title":"Proc. Natl. Acad. Sci. U. S. A."},{"key":"2026081502121207200_cit26","first-page":"1713","article-title":"Intestinal\nElectrolyte Absorption and Secretion","volume-title":"Sleisenger\nand Fordtran\u2019s Gastrointestinal and Liver Disease","author":"Rao","year":"2016","edition":"10"},{"key":"2026081502121207200_cit27","doi-asserted-by":"publisher","first-page":"761","DOI":"10.1016\/j.bbamem.2008.11.024","article-title":"Tight Junctions and the Regulation of Gene Expression","volume":"1788","author":"Balda","year":"2009","journal-title":"Biochim. Biophys. Acta, Biomembr."},{"key":"2026081502121207200_cit28","doi-asserted-by":"publisher","first-page":"660","DOI":"10.1016\/j.bbamem.2007.07.012","article-title":"Adherens and Tight\nJunctions: Structure, Function and\nConnections to the Actin Cytoskeleton","volume":"1778","author":"Hartsock","year":"2008","journal-title":"Biochim.\nBiophys. Acta, Biomembr."},{"key":"2026081502121207200_cit29","doi-asserted-by":"publisher","first-page":"1819","DOI":"10.1002\/cphy.c110045","article-title":"Claudins and Other Tight Junction\nProteins","volume":"2","author":"Gu\u0308nzel","year":"2012","journal-title":"Compr. Physiol."},{"key":"2026081502121207200_cit30","doi-asserted-by":"publisher","first-page":"1123","DOI":"10.1023\/A:1018903931777","article-title":"Selective\nParacellular Permeability\nin Two Models of Intestinal Absorption: Cultured Monolayers of Human\nIntestinal Epithelial Cells and Rat Intestinal Segments","volume":"10","author":"Artursson","year":"1993","journal-title":"Pharm. Res."},{"key":"2026081502121207200_cit31","doi-asserted-by":"publisher","first-page":"335","DOI":"10.1080\/10611860902839502","article-title":"Colonic Treatments and Targets: Issues and Opportunities","volume":"17","author":"McConnell","year":"2009","journal-title":"J. Drug Target."},{"key":"2026081502121207200_cit32","doi-asserted-by":"publisher","first-page":"2807","DOI":"10.1002\/jps.24372","article-title":"A Sensitive\nMedium-Throughput Method to Predict Intestinal Absorption in Humans\nUsing Rat Intestinal Tissue Segments","volume":"104","author":"Da\nSilva","year":"2015","journal-title":"J. Pharm.\nSci."},{"key":"2026081502121207200_cit33","doi-asserted-by":"crossref","first-page":"625","DOI":"10.4103\/0250-474X.78533","article-title":"Determination\nof Site of Absorption of Propranolol in Rat Gut Using in Situ Single-Pass\nIntestinal Perfusion","volume":"72","author":"Nagare","year":"2010","journal-title":"Indian J. Pharm. Sci."},{"key":"2026081502121207200_cit34","doi-asserted-by":"publisher","first-page":"329","DOI":"10.1124\/dmd.115.068429","article-title":"Functional Comparison of Human Colonic Carcinoma Cell\nLines and Primary Small Intestinal Epithelial Cells for Investigations\nof Intestinal Drug Permeability and First-Pass Metabolism","volume":"44","author":"Yamaura","year":"2016","journal-title":"Drug Metab. Dispos."},{"key":"2026081502121207200_cit35","doi-asserted-by":"publisher","first-page":"1627","DOI":"10.3390\/molecules22101627","article-title":"Intestinal Absorption of Triterpenoids and Flavonoids\nfrom Glycyrrhizae Radix et Rhizoma in the Human Caco-2 Monolayer Cell\nModel","volume":"22","author":"Wang","year":"2017","journal-title":"Molecules"},{"key":"2026081502121207200_cit36","doi-asserted-by":"publisher","first-page":"1192","DOI":"10.1023\/A:1025096930604","article-title":"Rhodamine 123 Requires Carrier-Mediated\nInflux for\nIts Activity as a P-Glycoprotein Substrate in Caco-2 Cells","volume":"20","author":"Troutman","year":"2003","journal-title":"Pharm. Res."},{"key":"2026081502121207200_cit37","doi-asserted-by":"publisher","first-page":"113","DOI":"10.1016\/S0378-5173(03)00372-7","article-title":"Caco-2 Permeability,\nP-Glycoprotein Transport Ratios and Brain Penetration of Heterocyclic\nDrugs","volume":"263","author":"Faassen","year":"2003","journal-title":"Int. J. Pharm."},{"key":"2026081502121207200_cit38","doi-asserted-by":"publisher","first-page":"353","DOI":"10.1590\/S1984-82502012000300002","article-title":"Overview of P-Glycoprotein\nInhibitors: A Rational Outlook","volume":"48","author":"Srivalli","year":"2012","journal-title":"Braz. J. Pharm.\nSci."},{"key":"2026081502121207200_cit39","doi-asserted-by":"publisher","first-page":"357","DOI":"10.1042\/BJ20110326","article-title":"Intestinal\nAbsorption of Water-Soluble Vitamins in Health and Disease","volume":"437","author":"Said","year":"2011","journal-title":"Biochem. J."},{"key":"2026081502121207200_cit40","doi-asserted-by":"publisher","first-page":"693","DOI":"10.1016\/j.mam.2012.07.014","article-title":"Novel Riboflavin Transporter Family RFVT\/SLC52: Identification, Nomenclature,\nFunctional Characterization and Genetic Diseases of RFVT\/SLC52","volume":"34","author":"Yonezawa","year":"2013","journal-title":"Mol. Aspects Med."},{"key":"2026081502121207200_cit41","doi-asserted-by":"publisher","first-page":"77","DOI":"10.1002\/1099-081X(200003)21:2&lt;77::AID-BDD211&gt;3.0.CO;2-A","article-title":"Carrier-mediated\nTransport\nof Riboflavin in the Rat Colon","volume":"21","author":"Yuasa","year":"2000","journal-title":"Biopharm. Drug\nDispos."},{"key":"2026081502121207200_cit42","doi-asserted-by":"publisher","first-page":"597","DOI":"10.1038\/nrd3187","article-title":"Coexistence of Passive and Carrier-Mediated Processes in Drug Transport","volume":"9","author":"Sugano","year":"2010","journal-title":"Nat. Rev. Drug Discovery"}],"container-title":["Analytical Chemistry"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pubs.acs.org\/doi\/pdf\/10.1021\/acs.analchem.8b02845","content-type":"application\/pdf","content-version":"vor","intended-application":"unspecified"},{"URL":"https:\/\/pubs.acs.org\/ancham\/article-pdf\/90\/22\/13331\/8493774\/ac8b02845.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/pubs.acs.org\/ancham\/article-pdf\/90\/22\/13331\/8493774\/ac8b02845.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,15]],"date-time":"2026-08-15T13:31:43Z","timestamp":1786800703000},"score":1,"resource":{"primary":{"URL":"https:\/\/pubs.acs.org\/ancham\/article\/90\/22\/13331\/820370\/A-Monolayer-of-Primary-Colonic-Epithelium"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2018,10,16]]},"references-count":42,"journal-issue":{"issue":"22","published-online":{"date-parts":[[2018,10,16]]},"published-print":{"date-parts":[[2018,11,20]]}},"URL":"https:\/\/doi.org\/10.1021\/acs.analchem.8b02845","relation":{},"ISSN":["0003-2700","1520-6882"],"issn-type":[{"value":"0003-2700","type":"print"},{"value":"1520-6882","type":"electronic"}],"subject":[],"published":{"date-parts":[[2018,10,16]]}}}