Accurate monitoring of steatotic liver disease (SLD) remains challenging, particularly in capturing the spatial distribution of different types of SLD targets within a tissue-like complex physiological matrix. In this study, we developed a novel hydrogel-based three-dimensional (3D) in vitro fatty liver mimic model enabling simultaneous in situ detection and imaging of key SLD biomarkers. This model was constructed by integrating nucleic acid probes into a gelatin methacrylate photo-cross-linkable hydrogel, which served as a biomimetic scaffold for fatty liver cells and their secreted targets. Within this 3D matrix, vaspin binding restored FAM fluorescence via aptamer displacement, while miRNA-122 initiated a hybridization chain reaction to amplify Cy3 signals, enabling dual-target spatiotemporal imaging. The assay achieved simultaneous detection in both solution and the 3D scaffold, with broad linear ranges of 10 pM-1 μM for vaspin and 1 pM-1 μM for miRNA-122, and limits of detection of 4.3 pM and 0.1 pM, respectively. A key novel finding in this study revealed a distinct difference in the spatial diffusion dynamics between protein and miRNA targets within a 3D cellular microenvironment. Our research indicated that vaspin diffused extensively into the periphery of the 3D space, while miRNA-122 remained more localized, which is unobservable in conventional 2D cultures. This platform enables in situ 3D dual-target monitoring in SLD, underscoring the critical importance of early in situ detection across multiple dimensions, including target source, 3D imaging, and information analysis. This integrated system provided a powerful preclinical tool for early SLD monitoring and targeted screening.
Song et al. (Sun,) studied this question.