Dual-axis Rotating Capillary Containers for 3D Culturing of Spheroids

Spheroids have found broad applications across biomedical engineering, including tissue modeling and drug screening; however, current culturing methods remain limited in terms of structural stability, uniformity, and scalability. To address these challenges, we developed the Dual‑axis Rotating Capillary Containers (DRCC) platform, a contact‑free system for rapid and uniform spheroid formation. The DRCC platform consists of an array of capillary‑based containers paired with a dual‑axis rotational unit. The capillary containers efficiently capture and release cell suspensions, while the dual‑axis rotation counteracts gravitational settling and promotes homogeneous self‑assembly into compact spheroids. Using this system, spheroids with tunable diameters ranging from 100 to 1300 µm were formed within 24 h while maintaining cell viability exceeding 95 %. Compared with spheroids produced using commercial systems, DRCC‑cultured spheroids showed markedly enhanced mechanical stability and a higher compressive modulus with 4 times increase, indicative of stronger intercellular cohesion. Notably, they also exhibited enhanced drug‑penetration barriers that more closely mimic in vivo solid tumors, as evidenced by significantly reduced doxorubicin uptake. This behavior correlates with the upregulated secretion of connexins and collagen in DRCC spheroids, as revealed by transcriptomic and immunofluorescence analyses. Furthermore, the platform enabled the construction of complex co‑culture spheroids that recapitulate the spatial architecture of the tumor microenvironment. Together, the DRCC platform offers a robust, efficient, and controllable tool for generating high‑fidelity spheroids, advancing their use in disease modeling, drug screening, and tissue engineering.