Three-dimensional hepatic lobule-like tissue constructs using cell-microcapsule technology

The proper functioning of the liver and tissues containing hepatocytes greatly depends upon the intricate organization of the cells. Consequently, controlling the shape of three-dimensional (3D) cellular constructs is an important issue for in vitro applications of fabricated artificial livers. However, the precise control of tissue shape at the microscale cannot be achieved with various commonly used 3D tissue-engineered building units, such as spheroids. Here, we present the fabrication of hepatic lobule-shaped microtissue (HLSM) containing rat liver (RLC-18) cells. By using cell-microcapsule technology, RLC-18 cells were encapsulated in the core region of poly-L-lysine-alginate microcapsules. After 14 days of long-term cultivation, RLC-18 cells self-assembled into HLSM, and the cells fully occupied the microcapsule. By monitoring the cell number and albumin secretion during culture and characterizing the dimensions of the fabricated tissue, we demonstrated that the HLSM showed higher hepatic function as compared with normal cell spheroids. We also showcased the assembly of these microtissues into a 3D four-layered hepatic lobule model by a facile micromanipulation method. Our technology for fabricating 3D multilayer hepatic lobule-like, biofunctional tissue enables the precise control of tissue shape in three dimensions. Furthermore, these constructs can serve as tissue-engineered building blocks for larger organs and cellular implants in clinical treatment.