Recent advances in microfabrication technologies have enabled us to construct collagen gel microbeads, which can be cultured with hepatocytes. However, little is known about the hepatocyte-collagen gel microbead interactions. Here, we aimed to clarify the effects of the balance between cell-cell and cell-collagen gel microbead interactions on hepatocyte morphogenesis and functions. The magnitude of cell-microbead interactions was controlled by changing the size of the microbeads, which were smaller than, comparable to, and larger than hepatocytes. These small, medium, and large microbeads were cultured separately with primary hepatocytes. Phase-contrast and time-lapse imaging revealed that the medium microbeads significantly induced the construction of 3D structures composed of the microbeads and hepatocytes in a self-organizing manner, whereas hepatocytes formed 2D monolayers with the small or large microbeads. These results suggest that only the medium microbeads induced the 3D tissue formation of hepatocytes. Furthermore, liver-specific functions, such as albumin secretion and ammonia clearance, were significantly upregulated in the 3D structures. These findings are critical to understand how to control the construction of 3D hepatocyte tissues with hydrogel microbeads in the context of biofabrication.

中文翻译：

---

肝细胞形态发生的自组织取决于胶原微珠相对于肝细胞的大小。

微加工技术的最新进展使我们能够构建可以与肝细胞一起培养的胶原蛋白凝胶微珠。然而，关于肝细胞-胶原凝胶微珠相互作用的了解甚少。在这里，我们旨在阐明细胞-细胞和细胞-胶原凝胶微珠相互作用之间平衡对肝细胞形态发生和功能的影响。细胞-微珠相互作用的大小通过改变微珠的大小来控制，微珠的大小小于，可比且大于肝细胞。将这些小，中和大微珠分别与原代肝细胞一起培养。相差和延时成像显示，中微珠以自组织方式显着诱导了由微珠和肝细胞组成的3D结构的构建，肝细胞与小或大微珠形成二维单层。这些结果表明，只有中微珠诱导肝细胞的3D组织形成。此外，肝脏特异性功能（例如白蛋白分泌和氨清除）在3D结构中显着上调。这些发现对于了解如何在生物制造的背景下利用水凝胶微珠控制3D肝细胞组织的构建至关重要。