Background:A potential treatment for healing hepatic tissue is delivering isolated hepatic cells to the site of injury to promote hepatic cells formation. In this technology, providing an appropriate injectable system for delivery of hepatic cells is an important issue. In this regard, fibrin scaffolds were designed with many advantages over other scaffolds like cell delivery vehicles for biodegradation, biocompatibility and hemostasis.Objectives:The aim of this study was to determine suitable cell culture circumstances for HepG2 cell proliferation and differentiation in 3D fibrin scaffolds by evaluating Ca2+ concentrations, cell numbers, various ratios of plasma/RPMI 1640 and thickness of fibrin scaffold.Materials and Methods:In a one-stage experimental design, Box-Behnken design strategy was performed by Minitab 15 software (version 15, Minitab. State College, PA) with three factors at three levels (low, medium and high) and 27 runs for identification of the effects of ratio of plasma/RPMI 1640, Ca2+ concentration and thickness on the formation of fibrin gel scaffold and 3D HepG2 culture.Results:The optimal concentrations for fibrin scaffold fabrication were achieved by adding 0.15 mol CaCl2 (50 µL) and 1 × 105 cells to 1:4 of plasma/RPMI 1640 ratio (500 µL with 2.3 mm thickness per well).Conclusions:Our approach provided easy handle method using inexpensive materials like human plasma instead of purified fibrinogen to fabricate fibrin scaffold.