Cell sheet-based multilayered liver tumor models for anti-cancer drug screening.

Objective: To fabricate in vitro cell-dense, three-dimensional (3D) tumor models by employing a cell sheet technology for testing anti-cancer drug efficacy.

Results: The stratified liver tumor models were fabricated by stacking contiguous HepG2 cell sheets. Triple-layer (3L), double-layer (2L), single-layer (1L) cell sheet-based liver tumor models (CSLTMs) demonstrated 106, 96, 85% cell viability, respectively, after 3 days treatment of 10 µM doxorubicin hydrochloride (DOX), while cell viability in two-dimensional (2D) conventional culture (control) was 27%. After 7 days of DOX treatment, the viabilities of 3L, 2L, 1L, control were 24, 14, 3 and 4%, respectively. Probable explanations were blocked diffusion of DOX by the intact and multilayered structure and also hypoxia in the bottom of multilayered cell sheets.

Conclusion: CSLTMs showed a thickness-dependent cytotoxic efficacy of DOX and greater drug resistance than the control, thereby providing useful information toward the development of improved biomimetic tumor models.