Recent Advances in Three-Dimensional In Vitro Models for Studies of Liver Fibrosis

Background: Liver fibrosis is a reversible but complex pathological condition associated with chronic liver diseases, affecting over 1.5 billion people worldwide. It is characterized by excessive extracellular matrix deposition resulting from sustained liver injury, often advancing to cirrhosis and cancer. As its progression involves various cell types and pathogenic factors, understanding the intricate mechanisms is essential for the development of effective therapies. In this context, extensive efforts have been made to establish three-dimensional (3D) in vitro platforms that mimic the progression of liver fibrosis. Methods: This review outlines the pathophysiology of liver fibrosis and highlights recent advancements in 3D in vitro liver models, including spheroids, organoids, assembloids, bioprinted constructs, and microfluidic systems. It further assesses their biological relevance, with particular focus on their capacity to reproduce fibrosis-related characteristics. Results: 3D in vitro liver models offer significant advantages over conventional two-dimensional cultures. Although each model exhibits unique strengths, they collectively recapitulate key fibrotic features, such as extracellular matrix remodeling, hepatic stellate cell activation, and collagen deposition, in a physiologically relevant 3D setting. In particular, multilineage liver organoids and assembloids integrate architectural complexity with scalability, enabling deeper mechanistic insights and supporting therapeutic evaluation with improved translational relevance. Conclusion: 3D in vitro liver models represent a promising strategy to bridge the gap between in vitro studies and in vivo realities by faithfully replicating liver-specific architecture and microenvironments. With enhanced reproducibility through standardized protocols, these models hold great potential for advancing drug discovery and facilitating the development of personalized therapies for liver fibrosis.