摘要：Multicellular microtissues of primary human hepatocytes(PHHs)co-cultured with other supporting cell types are a promis-ing model for drug screening and toxicological ***,these liver microtissues(LMs)rapidly lose their functions during ex vivo ***,in order to mimic the cellular and structural hepatic microenvironment,we co-cultured PHHs with human mesenchymal stromal cells(MSCs)and human umbilical vein endothelial cells(HUVECs)in the presence of cell-sized microparticles(MPs)derived from liver extracellular matrix(LEMPs).The microwell culture platform enabled biofabrication of size-controlled multicellular microtissues(PHH:HUVEC:MSC=3:2:1)with efficient LEMP incorporation(about 70%at a 2:1 ratio of cells:MP).The biofabricated liver microtissues(BLMs)were cultured ex vivo for 14 days and compared to the cell-only LM in terms of gene and protein expression,functional activity,cytochrome P450(CYP450)enzyme inducibility,and drug *** results supported superior hepatic-related gene expression,functional activity,and polarity for PHH in BLM compared to ***450 enzyme inducibility and dose-responsive sensitivity to toxic drugs were significantly higher in the BLM *** conclusion,microtissue engineering by incorporation of tissue-specific microparticles within a multicellular microtissue can offer some advantages for drug discovery studies and cell transplantation *** the near future,this approach could generate a scalable platform of several functional biofabricated microtissues representing different organs.