“…In recent years, adult rat hepatocytes inoculated on some surfaces were reported to form spheroidal aggregates (spheroids), and they expressed higher liver-specific functions in longer term as compared to conventional monolayer cultures (Landry et al, 1985;Koide et al, 1989;Koide et al, 1990;Sakai and Suzuki, 1991a;Sakai and Suzuki, 1991b). In recent years, adult rat hepatocytes inoculated on some surfaces were reported to form spheroidal aggregates (spheroids), and they expressed higher liver-specific functions in longer term as compared to conventional monolayer cultures (Landry et al, 1985;Koide et al, 1989;Koide et al, 1990;Sakai and Suzuki, 1991a;Sakai and Suzuki, 1991b).…”