Rapid, Large-scale, and Precise Cell Assembly for Tumor Model Fabrication via Template-modulated Flow-driven Strategy

Biomimetic performance of organoids heavily relies on rapid, precise, and programmable cell patterning at large scales. However, current methods, such as 3D printing, external field-driven cell assembly, and template-assisted cell assembly, face challenges in achieving high precision, rapid processing, and large-scale production simultaneously. To overcome these limitations, a flow-driven cell assembly (FDCA) strategy is introduced. Utilizing directional drag force in a template-modulated flow field, cells can be patterned on a micropore membrane, subsequently imprinted onto a substrate. Following the principle of layer-by-layer fabrication, the slices can be stacked to compose a 3D architecture. This approach enables fast, large-scale fabrication with precise cell patterning. To validate the platform's effectiveness, epithelial-mesenchymal transition (EMT) process of the assembled A549 cells is examined. Compared to cells cultured in 2D well plates or 3D spheroids, after treatment with TGF-β, cells patterned via the FDCA method exhibited more realistic variations in cytoskeletal structure and the expression levels of metastasis-related proteins, as well as an improvement in the capability of cell invasion. This strategy is believed offers a novel approach for rapid fabrication of large, precise organoids as well as in vitro cancer models, with promising applications in physiological research, drug screening, and organ transplantation.