A tissue engineering approach for liver tissue organization in vitro

我们先前描述了在细胞悬液中大量制备肝细胞球状体。已发现将合成聚合物Eudragit S 100（甲基丙烯酸和甲基丙烯酸甲酯的共聚物）作为人工基质添加到培养基中可促进细胞聚集并诱导球状体形成。本研究探讨了肝细胞和肝非实质细胞的共培养，以进一步增强肝功能的稳定表达。向培养基中加入聚合物也可形成由肝细胞和非实质细胞组成的异球体。肝功能的表达水平取决于细胞的混合比例，当肝细胞和非实质细胞混合时，白蛋白分泌、贫血清除和尿素合成的值最高。与不含聚合物的共培养细胞和仅由肝细胞组成的球状体相比，异球状体维持了更高水平的白蛋白分泌超过4周。其他肝功能，如anunonia去除和细胞色素P-450活性在'异球体培养物中也保持在整个4周培养期间的高水平。

We previously described the mass preparation ofhepatocyte spheroids in a cell suspension. Addition ofa synthetic polymer, Eudragit S 100 (a co-polymer of methacrylic acid and methylmethacrylate), to the culture medium as an artificial matrix has been found to promote cell aggregation and induce spheroid formation. The present study examines co-cultures of hepatocytgs and liver non-parenchymal cells to further enhance the stable expression of liver functions. Hetero-spheroids consisting of "hepatocyteT.and non-parenchymal cells were also formed by adding the polymer to the culture medium. The expression levels of liver functions depended on the mixing ratio of the cells The values ofalbumin secretion, anmlonia removal and urea synthesis were the highest when equal number ofhepatocytes and non-parenchymal cells were mixed. The hetero-spherpids maintained a higher level ofalbumin secretion for over 4 weeks^compared with co-cultured cells without the polymer and spheroids consisting of hepatocytes solely.^Other liver functions such as anunonia removal and cytochrome P-450 activity in'hetero-spheroid cultures were also maintained at a high level throughout the 4-week culture period.