Vascularized Liver‐on‐a‐Microsphere Reveals Alanine‐Glucose Metabolism‐Driven Regulation of Liver Function and Injury

The hepatic lobule, the basic unit of the liver, spatially organizes diverse cell types to coordinate metabolism, detoxification, and immune regulation. Yet efficiently reconstructing its hierarchical and vascular microarchitecture in vitro remains a central challenge. Here, we report a vascularized liver-on-a-microsphere (VLOM) system that recreates lobule-like structure and function within individual microscale hydrogel particles. Using a microfluidic-aerosol fabrication strategy, compartmentalized microspheres with rough-textured surface and built-in spatial addressing markers were produced to spatially localize multiple liver cell types and support endothelial barrier formation. The VLOMs exhibit uniform morphology, structural stability, and high viability, accompanied by enhanced hepatic performance, including elevated albumin and urea synthesis and upregulated CYP2B6 and CYP3A4 expression. Metabolomic profiling reveals activation of the alanine-glucose metabolic cycle, which strengthens biosynthetic and detoxification capacities. Supplementation with alanine or glucose further restores hepatic function and mitigates rifampicin-induced hepatotoxicity, underscoring the protective role of this cycle in maintaining metabolic resilience. This scalable, vascularized microsphere system unites microengineering precision and physiological fidelity, offering a high-throughput route to model liver metabolism and evaluate drug responses.