Bioengineered Tubular Biliary Organoids

Abstract Liver organoids have emerged as promising in vitro models for toxicology, drug discovery, and disease modeling. However, conventional 3D epithelial organoid culture systems suffer from significant drawbacks, including limited culture duration, a nonphysiological 3D cystic anatomy with an inaccessible apical surface, and lack of in vivo‐like cellular organization. To address these limitations, herein a hydrogel‐based organoid‐on‐a‐chip model for the development functional tubular biliary organoids is reported. The resulting constructs demonstrate long‐term stability for a minimum duration of 45 d, while retaining their biliary organoid identity and exhibiting key cholangiocyte characteristics including transport activities, formation of primary cilia, and protective glycocalyx. Additionally, tubular organoids are susceptible to physical and chemical injury, which cannot be applied in such resolution to classical organoids. To enhance tissue‐level complexity, in vitro formation of a perfusable branching network is induced using a predetermined geometry that faithfully mimics the intricate structure of the intrahepatic biliary tree. Finally, cellular complexity is augmented through co‐culturing with vascular endothelial cells and fibroblasts. The models described in this study offer valuable opportunities for investigating biliary morphogenesis and elucidating associated pathophysiological mechanisms.