Abstract

Medulloblastoma (MB) is a common intracranial malignant tumor in children with a poor prognosis and high mortality rate. The lack of suitable models has hampered basic research and preclinical drug screening for MB. Three-dimensional (3D) bioprinting enables organoid construction that recapitulates primary tumors and supports high-throughput drug testing. Here, we report a novel silk fibroin (SF)-based ternary bioink optimized for 3D bioprinting and, for the first time, the fabrication of a 3D bioprinted MB organoid model along with its modular and detachable co-culture system. This ternary bioink exhibited high mechanical strength, demonstrating a significant enhancement in the extracellular matrix (ECM) stiffness while maintaining stable structural performance over 28 days in culture. Verification at the genetic and protein levels confirmed that key signal pathways, notably PI3K/AKT and Ras, were activated in the 3D MB organoid model. Consequently, tumor cells displayed enhanced malignant phenotypes, including proliferation, migration and invasion, alongside increased chemoresistance. Moreover, co-culture of MB organoids provides evidence for the critical role of vascular endothelial-tumor cell interactions in driving tumor drug resistance, offering a viable pathway to advance from simplified models to more physiologically complex systems. These phenotypic changes enable more accurate prediction of the in vivo therapeutic efficacy of anti-MB drug candidates. In summary, this study developed a set of long-term stable and flexibly configurable 3D bioprinted MB organoid models that address critical gaps in the existing preclinical systems, thereby enabling more reliable drug screening and pathological studies for MB.