Provided are a technique for easily forming a spheroid by three-dimensionally culturing hepatocytes, and a technique for forming a spheroid having a higher expression level of a transporter MRP2 playing a role of biliary excretion than that of a conventional method. In order to solve the above-described problems, the present inventors have found out a condition under which hepatocytes easily form the spheroid on a nanopillar sheet. More specifically, this is related to a concentration of Type I collagen coated onto the NP sheet. Also, they have found out a condition under which an expression level of a gene related to the excretion of the formed spheroid is improved. More specifically, after the spheroid is previously formed, a biological matrix is overlayered thereon.
本发明提供了一种通过三维培养肝细胞轻松形成球形体的技术,以及一种与传统方法相比具有更高表达
水平的起胆汁排泄作用的转运体 MRP2 的球形体形成技术。为了解决上述问题,本发明人发现了一种条件,在这种条件下,肝细胞很容易在纳米柱薄片上形成球体。更具体地说,这与涂在纳米柱薄片上的 I 型
胶原蛋白的浓度有关。此外,他们还发现了一种条件,在这种条件下,与已形成的小球的排泄有关的
基因的表达
水平会得到改善。更具体地说,在先前形成球体后,在其上覆盖一层
生物基质。