ABSTRACT Liver tissue function relies on cells' spatial organization and interactions within a 3D microenvironment. While previously reported liver‐on‐a‐chip models effectively provide basic structural organization and multilayered arrangements using artificial barriers, they fall short in replicating the higher‐order organization of diverse cell types. Herein, we fabricated a membrane‐free liver‐on‐a‐chip (MF‐LOC) using CGRGDS peptide‐modified PEGDA hydrogel that not only provides a native‐like 3D microenvironment for encapsulated HepG2 (Hepatocytes) cells and NIH‐3T3 (fibroblasts) but also offers a platform for HUVEC monolayer formation. The immobilization of the CGRGDS peptide on the hydrogel surface, which operates at a nanoscale level to enhance cell adhesion and signaling via integrin binding, strengthens HUVEC adhesion and prevents cell detachment caused by the shear stress of direct tangential flow. In MF‐LOC, nutrients easily diffuse through the HUVEC monolayer and hydrogel pores to sustain cell functions. Live/Dead imaging and cell tracking showed HepG2 clusters associated with neighboring NIH‐3T3 fibroblasts, with HUVECs forming a surface monolayer which replicate native liver structure. Functional validation confirmed prolonged albumin and urea secretion, with MF‐LOC exhibiting sustained CYP1A1 enzyme activity compared to gold standard microsomes, highlighting its ability to replicate liver‐like metabolism. MF‐LOC has the potential for predicting drug‐induced liver injury (DILI) and may provide a powerful platform for disease modeling.
Sati et al. (Tue,) studied this question.