In vitro NAFLD model based on 3D-printed liver tissue: Establishment and applications

Nonalcoholic fatty liver disease is a prevalent chronic disease worldwide, but its underlying etiology and molecular mechanisms are complex, and there are currently no effective clinical treatments. Animal models for studying NAFLD have limitations, necessitating the development of novel in vitro models. In this study, a bioink was first optimized for the cultivation of liver tissue. Subsequently, 3D bioprinting technology was utilized to construct large-scale liver tissue with a vascular-like function in vitro using the optimized bioink. Thereafter, the printed HepaRG cells were induced to form liver organoids. Compared with traditional liver tissue models, 3D-printed liver tissue has superior hepatic functions and greater cell viability. Moreover, the storage of glycogen and the formation of bile canaliculi-like structures were observed within it. Subsequently, 3D-printed liver tissue was induced to establish a NAFLD model, which was confirmed by lipid droplet analysis, liver function assays, and cell viability assessments. Additionally, this NAFLD model was used for drug testing and analysis. Our study successfully constructed a functional NAFLD model, which contributes to a deeper understanding of the mechanisms underlying NAFLD, facilitates the development of related pharmaceuticals, and promotes the development of new therapeutic strategies.