{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,12]],"date-time":"2026-09-12T03:00:55Z","timestamp":1789182055380,"version":"build-2803163510"},"reference-count":46,"publisher":"MDPI AG","issue":"21","license":[{"start":{"date-parts":[[2020,10,27]],"date-time":"2020-10-27T00:00:00Z","timestamp":1603756800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>Several inflammatory conditions of the bile ducts cause strictures that prevent the drainage of bile into the gastrointestinal tract. Non-pharmacological treatments to re-establish bile flow include plastic or self-expanding metal stents (SEMs) that are inserted in the bile ducts during endoscopic retrograde cholangiopancreatography (ERCP) procedures. The focus of this study was to 3D print an anatomically accurate model of the extrahepatic bile ducts (EHBDs) with tissue-like mechanical properties to improve in vitro testing of stent prototypes. Following generation of an EHBD model via computer aided design (CAD), we tested the ability of Formlabs SLA 3D printers to precisely print the model with polymers selected based on the desired mechanical properties. We found the printers were reliable in printing the dimensionally accurate EHBD model with candidate polymers. Next, we evaluated the mechanical properties of Formlabs Elastic (FE), Flexible (FF), and Durable (FD) resins pre- and post-exposure to water, saline, or bile acid solution at 37 \u00b0C for up to one week. FE possessed the most bile duct-like mechanical properties based on its elastic moduli, percent elongations at break, and changes in mass under all liquid exposure conditions. EHBD models printed in FE sustained no functional damage during biliary stent deployment or when tube connectors were inserted, and provided a high level of visualization of deployed stents. These results demonstrate that our 3D printed EHBD model facilitates more realistic pre-clinical in vitro testing of biliary stent prototypes.<\/jats:p>","DOI":"10.3390\/ma13214788","type":"journal-article","created":{"date-parts":[[2020,10,27]],"date-time":"2020-10-27T09:22:45Z","timestamp":1603790565000},"page":"4788","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":14,"title":["3D Printed Model of Extrahepatic Biliary Ducts for Biliary Stent Testing"],"prefix":"10.3390","volume":"13","author":[{"given":"Joanna","family":"Thomas","sequence":"first","affiliation":[{"name":"Biomedical Engineering Department, Mercer University, Macon, GA 31207, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sagar","family":"Patel","sequence":"additional","affiliation":[{"name":"Biomedical Engineering Department, Mercer University, Macon, GA 31207, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Leia","family":"Troop","sequence":"additional","affiliation":[{"name":"Biomedical Engineering Department, Mercer University, Macon, GA 31207, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Robyn","family":"Guru","sequence":"additional","affiliation":[{"name":"Biomedical Engineering Department, Mercer University, Macon, GA 31207, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nicholas","family":"Faist","sequence":"additional","affiliation":[{"name":"Biomedical Engineering Department, Mercer University, Macon, GA 31207, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Brian J.","family":"Bellott","sequence":"additional","affiliation":[{"name":"Chemistry Department, Western Illinois University, Macomb, IL 61455, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bethany A.","family":"Esterlen","sequence":"additional","affiliation":[{"name":"Chemistry Department, Western Illinois University, Macomb, IL 61455, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,10,27]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"22","DOI":"10.1093\/gastro\/gou072","article-title":"Biliary strictures: Diagnostic considerations and approach","volume":"3","author":"Singh","year":"2015","journal-title":"Gastroenterol. Rep."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1390","DOI":"10.1016\/j.bbadis.2017.08.020","article-title":"Cholangiocytes in the pathogenesis of primary sclerosing cholangitis and development of cholangiocarcinoma","volume":"1864","author":"Chung","year":"2018","journal-title":"Biochim. Biophys. Acta (BBA) Mol. Basis Dis."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"269","DOI":"10.1038\/s41575-019-0125-y","article-title":"Cholangiocyte pathobiology","volume":"16","author":"Banales","year":"2019","journal-title":"Nat. Rev. Gastroenterol. Hepatol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"193","DOI":"10.1258\/002367794780681714","article-title":"Replacement of animal procedures: Alternatives in research, education and testing","volume":"28","author":"Balls","year":"1994","journal-title":"Lab. Anim."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Myers, D. (2017). From in vivo to in vitro: The medical device testing paradigm shift. ALTEX, 479\u2013500.","DOI":"10.14573\/altex.1608081"},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Herrmann, K. (2019). Beyond the 3Rs: Expanding the use of human-relevant replacement methods in biomedical research. ALTEX, 343\u2013352.","DOI":"10.14573\/altex.1907031"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"819","DOI":"10.1016\/j.gie.2006.09.011","article-title":"Impact of reducing duodenobiliary reflux on biliary stent patency: An in vitro evaluation and a prospective randomized clinical trial that used a biliary stent with an antireflux valve","volume":"65","author":"Dua","year":"2007","journal-title":"Gastrointest. Endosc."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1056","DOI":"10.1007\/s10620-011-1958-6","article-title":"The Biodurability of Covering Materials for Metallic Stents in a Bile Flow Phantom","volume":"57","author":"Bang","year":"2012","journal-title":"Dig. Dis. Sci."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"156","DOI":"10.1016\/j.gie.2013.09.013","article-title":"The effect of a novel drug-eluting plastic stent on biliary stone dissolution in an ex vivo bile perfusion model","volume":"79","author":"Cai","year":"2014","journal-title":"Gastrointest. Endosc."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"3370","DOI":"10.3748\/wjg.v25.i26.3370","article-title":"Drug-eluting fully covered self-expanding metal stent for dissolution of bile duct stones in vitro","volume":"25","author":"Huang","year":"2019","journal-title":"WJG"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"23","DOI":"10.1186\/1475-925X-3-23","article-title":"Mechanical Properties of the Porcine Bile Duct Wall","volume":"3","author":"Duch","year":"2004","journal-title":"Biomed. Eng. Online"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"741","DOI":"10.1016\/j.transproceed.2012.11.006","article-title":"Comparison of Biomechanical Properties of Bile Duct between Pigs and Humans for Liver Xenotransplant","volume":"45","author":"Li","year":"2013","journal-title":"Transplant. Proc."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"035010","DOI":"10.1088\/1758-5090\/aac902","article-title":"Tailoring nanostructure and bioactivity of 3D-printable hydrogels with self-assemble peptides amphiphile (PA) for promoting bile duct formation","volume":"10","author":"Yan","year":"2018","journal-title":"Biofabrication"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1884","DOI":"10.1038\/s41596-019-0168-0","article-title":"Isolation and propagation of primary human cholangiocyte organoids for the generation of bioengineered biliary tissue","volume":"14","author":"Tysoe","year":"2019","journal-title":"Nat. Protoc."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"84","DOI":"10.1016\/j.actbio.2018.12.039","article-title":"Directing the growth and alignment of biliary epithelium within extracellular matrix hydrogels","volume":"85","author":"Lewis","year":"2019","journal-title":"Acta Biomater."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Brevini, T., Tysoe, O.C., and Sampaziotis, F. (2020). Tissue engineering of the biliary tract and modelling of cholestatic disorders. J. Hepatol., S0168827820303676.","DOI":"10.1016\/j.jhep.2020.05.049"},{"key":"ref_17","first-page":"305","article-title":"Pseudocholangiocarcinoma Sign: Management of Portal Cavernoma Biliopathy with Fully-Covered Self-Expandable Metal Stent","volume":"50","author":"Horta","year":"2016","journal-title":"Clin. Endosc."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"79","DOI":"10.2214\/ajr.154.1.2104731","article-title":"CT of the extrahepatic bile ducts: Wall thickness and contrast enhancement in normal and abnormal ducts","volume":"154","author":"Schulte","year":"1990","journal-title":"Am. J. Roentgenol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1159","DOI":"10.1016\/j.suc.2008.07.001","article-title":"Biliary Anatomy and Embryology","volume":"88","author":"Vakili","year":"2008","journal-title":"Surg. Clin. N. Am."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Hamm, B., and Ros, P.R. (2013). Gallbladder and Biliary Tree Anatomy, Variants, Cystic Lesions. Abdominal Imaging, Springer.","DOI":"10.1007\/978-3-642-13327-5"},{"key":"ref_21","unstructured":"Terjung, R. (2013). Bile Formation and Secretion. Comprehensive Physiology, John Wiley & Sons, Inc."},{"key":"ref_22","first-page":"37","article-title":"Practical classification of the branching types of the biliary tree: An analysis of 1094 consecutive direct cholangiograms","volume":"182","author":"Yoshida","year":"1996","journal-title":"J. Am. Coll. Surg."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"389","DOI":"10.2214\/ajr.177.2.1770389","article-title":"Anatomic Variants of the Biliary Tree: MR Cholangiographic Findings and Clinical Applications","volume":"177","author":"Ros","year":"2001","journal-title":"Am. J. Roentgenol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"623","DOI":"10.1007\/s11605-011-1447-4","article-title":"Anatomic Variations of Intrahepatic Bile Ducts in a European Series and Meta-analysis of the Literature","volume":"15","author":"Cucchetti","year":"2011","journal-title":"J. Gastrointest. Surg."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"99","DOI":"10.22516\/25007440.136","article-title":"\u00bfCu\u00e1l es el tama\u00f1o normal del conducto biliar com\u00fan?","volume":"32","year":"2017","journal-title":"Rev. Colomb. Gastroenterol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"S18","DOI":"10.1016\/j.jceh.2013.05.002","article-title":"Biliary Tract Anatomy and its Relationship with Venous Drainage","volume":"4","author":"Sharma","year":"2014","journal-title":"J. Clin. Exp. Hepatol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1148\/radiographics.21.1.g01ja093","article-title":"The Cystic Duct: Normal Anatomy and Disease Processes","volume":"21","author":"Turner","year":"2001","journal-title":"Radiographics"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"2983","DOI":"10.1007\/s00268-015-3201-7","article-title":"Surgical and Radiological Studies on the Length of the Hepatic Ducts","volume":"39","author":"Hirose","year":"2015","journal-title":"World J. Surg."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1384","DOI":"10.3748\/wjg.v13.i9.1384","article-title":"On the mechanical behavior of the human biliary system","volume":"13","author":"Luo","year":"2007","journal-title":"World J. Gastroenterol."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"105","DOI":"10.3233\/BME-1991-1203","article-title":"Biomechanical Study of the Bile Duct System outside the Liver","volume":"1","author":"Jian","year":"1991","journal-title":"Bio-Med Mater. Eng."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1417","DOI":"10.1016\/S0021-9290(02)00084-2","article-title":"Mechanical properties of the human gastrointestinal tract","volume":"35","author":"Egorov","year":"2002","journal-title":"J. Biomech."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1225","DOI":"10.1089\/ten.tea.2018.0239","article-title":"Development of Intestinal Scaffolds that Mimic Native Mammalian Intestinal Tissue","volume":"25","author":"Ladd","year":"2019","journal-title":"Tissue Eng. Part. A"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"632","DOI":"10.5009\/gnl15417","article-title":"Bile Flow Phantom Model and Animal Bile Duct Dilation Model for Evaluating Biliary Plastic Stents with Advanced Hydrophilic Coating","volume":"10","author":"Kwon","year":"2016","journal-title":"Gut Liver"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"500","DOI":"10.1007\/s12015-016-9657-5","article-title":"Efficient and Controlled Generation of 2D and 3D Bile Duct Tissue from Human Pluripotent Stem Cell-Derived Spheroids","volume":"12","author":"Tian","year":"2016","journal-title":"Stem Cell Rev. Rep."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"954","DOI":"10.1038\/nm.4360","article-title":"Reconstruction of the mouse extrahepatic biliary tree using primary human extrahepatic cholangiocyte organoids","volume":"23","author":"Sampaziotis","year":"2017","journal-title":"Nat. Med."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"045004","DOI":"10.1088\/1748-605X\/ab797a","article-title":"A novel 3D printing PCL\/GelMA scaffold containing USPIO for MRI-guided bile duct repair","volume":"15","author":"Li","year":"2020","journal-title":"Biomed. Mater."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"247","DOI":"10.1038\/s41586-018-0075-5","article-title":"De novo formation of the biliary system by TGF\u03b2-mediated hepatocyte transdifferentiation","volume":"557","author":"Schaub","year":"2018","journal-title":"Nature"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"61","DOI":"10.1159\/000441720","article-title":"Implantation of a Tissue-Engineered Neo-Bile Duct in Domestic Pigs","volume":"56","author":"Struecker","year":"2015","journal-title":"Eur. Surg. Res."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"231","DOI":"10.1021\/acsbiomaterials.7b00794","article-title":"Multifunctional Bioreactor System for Human Intestine Tissues","volume":"4","author":"Zhou","year":"2018","journal-title":"ACS Biomater. Sci. Eng."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"327","DOI":"10.1016\/j.jss.2007.03.039","article-title":"A Perfusion Bioreactor for Intestinal Tissue Engineering","volume":"142","author":"Kim","year":"2007","journal-title":"J. Surg. Res."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"728","DOI":"10.1002\/sctm.19-0389","article-title":"Improving patient outcomes with regenerative medicine: How the Regenerative Medicine Manufacturing Society plans to move the needle forward in cell manufacturing, standards, 3D bioprinting, artificial intelligence-enabled automation, education, and training","volume":"9","author":"Hunsberger","year":"2020","journal-title":"Stem Cells Transl. Med."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"29","DOI":"10.1146\/annurev-med-102715-092331","article-title":"Tissue Engineering: Toward a New Era of Medicine","volume":"68","author":"Shafiee","year":"2017","journal-title":"Annu. Rev. Med."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"589","DOI":"10.1098\/rsif.2006.0124","article-title":"Challenges in tissue engineering","volume":"3","author":"Ikada","year":"2006","journal-title":"J. R. Soc. Interface"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"1124","DOI":"10.1016\/S0140-6736(14)60558-4","article-title":"Research: Increasing value, reducing waste","volume":"383","author":"Harron","year":"2014","journal-title":"Lancet"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"166","DOI":"10.1016\/S0140-6736(13)62227-8","article-title":"Increasing value and reducing waste in research design, conduct, and analysis","volume":"383","author":"Ioannidis","year":"2014","journal-title":"Lancet"},{"key":"ref_46","unstructured":"(2020, July 01). Formlabs Materials Medical. Available online: https:\/\/formlabs.com\/industries\/medical\/materials\/#elastic-50a-resin."}],"container-title":["Materials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1996-1944\/13\/21\/4788\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T10:28:59Z","timestamp":1760178539000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1996-1944\/13\/21\/4788"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,10,27]]},"references-count":46,"journal-issue":{"issue":"21","published-online":{"date-parts":[[2020,11]]}},"alternative-id":["ma13214788"],"URL":"https:\/\/doi.org\/10.3390\/ma13214788","relation":{},"ISSN":["1996-1944"],"issn-type":[{"value":"1996-1944","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,10,27]]}}}