3D-printed MOF-hydrogel microarray for multiplexed miRNA detection and early herb-induced liver injury warning.

Early warning of herb-induced liver injury (HILI) is hampered by the lack of biomarkers that are more sensitive and timelier than alanine/aspartate aminotransferase (ALT/AST). We previously identified miR-122 and miR-194 as a promising circulating miRNA biomarker panel for liver injury. To address the technical challenges of detecting such trace analytes, we developed a 3D-printed multifunctional metal-organic framework (MOF)-hydrogel microarray (3D-MHMA). The platform innovatively integrates UiO-66-NH2 MOF nanoparticles as dual-functional cores for fluorescence quenching and target enrichment, a catalytic hairpin assembly-hybridization chain reaction (CHA-HCR) cascade for enzyme-free signal amplification, and 3D bioprinting for fabricating a high-throughput, spatially encoded sensor array. The 3D-MHMA achieved ultra-sensitive detection of miR-122 and miR-194 with a detection limit of 2.61 fM. Validated in cellular and animal models of triptolide-induced liver injury, the platform reliably profiled these miRNAs, whose release significantly preceded the rise in serum ALT/AST levels, providing a superior early diagnostic window (area under the curve >0.9). This work presents an integrated solution coupling a high-performance sensing platform with a novel miRNA biomarker panel for the early warning of HILI.