TY - JOUR T1 - Conversion of iPS derived hepatic progenitors into scalable, functional and developmentally relevant human organoids using an inverted colloidal crystal poly (ethylene glycol) scaffold engineered from collagen-coated pores of defined size JF - bioRxiv DO - 10.1101/296327 SP - 296327 AU - Soon Seng Ng AU - Kourosh Saeb-Parsy AU - Joe M Segal AU - Maria Paola Serra AU - Samuel J I Blackford AU - Marta Horcas Lopez AU - Da Yoon No AU - Curtis W Frank AU - Nam Joon Cho AU - Hiromitsu Nakauchi AU - Jeffrey S Glenn AU - S Tamir Rashid Y1 - 2018/01/01 UR - http://biorxiv.org/content/early/2018/04/06/296327.abstract N2 - Generation of human organoids from induced pluripotent stem cells (iPSCs) offers exciting possibilities for developmental biology, disease modelling and cell therapy. Significant advances towards those goals have been hampered by dependence on animal derived matrices (e.g. Matrigel), immortalized cell lines and resultant structures that are difficult to control or scale. To address these challenges, we aimed to develop a fully defined liver organoid platform using inverted colloid crystal (ICC) whose 3-dimensional mechanical properties could be engineered to recapitulate the extracellular niche sensed by hepatic progenitors during human development. iPSC derived hepatic progenitors (IH) formed organoids most optimally in ICC scaffolds constructed with 140 µm diameter pores coated with Collagen in a two-step process mimicking liver bud formation. The resultant organoids were closer to adult tissue, compared to 2D and 3D controls, with respect to morphology, gene expression, protein secretion, drug metabolism and viral infection and could integrate, vascularize and function following implantation into livers of immune-deficient mice. Preliminary interrogation of the underpinning mechanisms highlighted the importance of TGFβ and hedgehog signalling pathways. The combination of functional relevance with tuneable mechanical properties leads us to propose this bioengineered platform to be ideally suited for a range of future mechanistic and clinical organoid related applications.Author ContributionAll authors contributed extensively to the work presented in this paper. S.S.N., C.W.F, N.J.C., H.N., J.S.G. and S.T.R. developed the study concept and design. S.S.N., K.S., J.M.S., M. P. S., S.J.I.B., M.H.L. and D.Y.N. acquired data. S.S.N., K.S., J.M.S., J.S.G. and S.T.R. analyzed and interpreted the data. S.S.N., J.S.G. and S.T.R. drafted the manuscript and revised the manuscript for important intellectual content. J.S.G. and S.T.R. supervised the study.AbbreviationsiPSCinduced pluripotent stem cellIHiPSC derived hepatic progenitorsFDAfood and drug administrationTGFβtransforming growth factor beta3Dthree-dimensionalICCinverted colloidal crystalPEGpolyethylene glycolECMextracellular matrixColcollagenFnfibronectinLnlamininCK19keratin 19ECAMepithelial cell adhesion moleculeAFPalpha-fetoproteinASGR1asialoglycoprotein receptor 1ALBalbuminHNF4ahepatocyte nuclear factor 4-alphaRT-qPCRreverse transcription-quantitative polymerase chain reaction2Dtwo-dimensionalRNA-seqRNA-sequenceDEiPSC derived definitive endodermPCAprinciple component analysisMRP2multidrug resistance protein 1BSEPbile-salt efflux pumpZO-1tight junction protein 1CLFcholyl-lysyl-flourescenceTGZTroglitazoneHCVhepatitis C virusCLDN1claudin 1OCLNoccludinSCARB1scavenger receptor class B type 1LDLRlow-density lipoprotein receptorHSGPheparin sulfate glycoproteinH&Ehematoxylin and eosinCYCcyclopamineHUVEChuman umbilical endothelial cellMSCmesenchymal stem cell ER -