A method of obtaining 3D cell structures including differentiated human hepatic cells. The method includes: a first step of culturing stem cell-derived or immortalized human hepatic progenitors in a non-adherent culture vessel, preferably a low or ultra-low attachment culture vessel; a second step of transferring the stem cell-derived or immortalized human hepatic progenitors to a culture medium including methacrylated gelatin (GelMa), thereby embedding the stem cell-derived or immortalized human hepatic progenitors in a GelMa matrix; and a third step of covering the GelMa matrix with culture medium and culturing the stem cell-derived or immortalized human hepatic progenitors embedded in the GelMa matrix, thereby obtaining 3D cell structures including differentiated human hepatic cells. Also, methods for engineering an artificial liver model or an artificial liver organ, and for assessing in vitro the metabolism, toxicity and/or therapeutic effects of a compound.