Background: We previously developed a rapid three-dimensional (3-D) tissue fabrication method using centrifugation. In this study, we fabricated 3-D HepG2 liver tissues using a scaffold-free centrifugation method and analyzed them biochemically. Methods: We investigated the conditions for fabricating HepG2 tissues by varying the number of seeded cells (1.25-20 × 106 cells/169 mm2). After two days of cultivation, cultured tissue cross-sections were examined. In addition, HepG2 tissues were cultured for an extended period (10 days), and biochemical metabolic analyses were performed. Results: Thick HepG2 tissue was rapidly fabricated by centrifugation. Optical coherence tomography observations indicated that tissue thickness increased with a higher number of seeded cells. However, after two days of cultivation, biochemical analyses and observations of the paraffin section indicated that tissues fabricated with over 5.0 × 106 cells were weak and damaged. However, the liver tissues fabricated using 1.25-2.5 × 106 cells were compact with high cell density. HepG2 tissue was cultured for 10 days; however, albumin production remained minimal. Conclusion: This study established optimal conditions for the rapid fabrication of HepG2 liver tissue. The proposed method holds significant potential for advancing liver tissue engineering and hepatocyte biology.
Ogawa et al. (Fri,) studied this question.