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

Abstract 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.