A scalable and cost-effective 3D tumor spheroid array chip for distortion-free optical monitoring and drug screening

This study presents a novel, cost-effective, and transparent tumor spheroid array chip fabricated via Mask Stereolithography (MSLA) 3D printing and Polydimethylsiloxane (PDMS) molding, enabling the scalable generation of thousands of uniform spheroids. The chip demonstrated excellent biocompatibility, supporting tumor spheroid growth with cell viability exceeding 95%. To validate the platform's utility, the efficacy of Doxorubicin (DOX) and two novel compounds (CNI3 and CNI3-2) were evaluated using the 3D chip and compared with traditional 2D monolayer cultures. The results revealed distinct drug resistance profiles in the 3D model, reflecting the physiological barriers typical of solid tumors; specifically, DOX induced 70% cytotoxicity in 2D cells at 0.3125 µM, whereas only 10% cytotoxicity was observed in 3D spheroids. Furthermore, the derivative CNI3-2 exhibited significantly enhanced potency compared to CNI3, achieving 50% cytotoxicity at 75 µM in 3D spheroids. In conclusion, by reproducing the drug resistance characteristics observed in vivo, this 3D tumor spheroid array chip provides a more clinically predictive model than traditional 2D methods, offering a robust solution for high-throughput screening that potentially bridges the gap between preclinical in vitro testing and clinical therapeutic outcomes.