Hepatic spheroid-on-a-chip: Fabrication and characterization of a spheroid-based in vitro model of the human liver for drug screening applications.

The integration of microfabrication and microfluidics techniques into cell culture technology has significantly transformed cell culture conditions, scaffold architecture, and tissue biofabrication. These tools offer precise control over cell positioning and enable high-resolution analysis and testing. Culturing cells in 3D systems, such as spheroids and organoids, enables recapitulating the interaction between cells and the extracellular matrix, thereby allowing the creation of human-based biomimetic tissue models that are well-suited for pre-clinical drug screening. Here, we demonstrate an innovative microfluidic device for the formation, culture, and testing of hepatocyte spheroids, which comprises a large array of patterned microwells for hosting hepatic spheroid culture in a reproducible and organized format in a dynamic fluidic environment. The device allows maintaining and characterizing different spheroid sizes as well as exposing to various drugs in parallel enabling high-throughput experimentation. These liver spheroids exhibit physiologically relevant hepatic functionality, as evidenced by their ability to produce albumin and urea at levels comparable to in vivo conditions and the capability to distinguish the toxic effects of selected drugs. This highlights the effectiveness of the microenvironment provided by the chip in maintaining the functionality of hepatocyte spheroids. These data support the notion that the liver-spheroid chip provides a favorable microenvironment for the maintenance of hepatocyte spheroid functionality.