Matrix micro/nano-topography drives oncogenic signaling and drug response in a 3D osteosarcoma model.

Osteosarcoma (OS) research is constrained by a scarcity of clinical samples and traditional models that inadequately replicate the natural micro/nano-structure of bone. The role of these topological features in sustaining cellular function and influencing drug response remains insufficiently understood in OS. To address these challenges, a composite alginate-hydroxyapatite (AlgHA) cryogel was developed by incorporating bone-derived hydroxyapatite into an alginate-based cryogel matrix, which simultaneously enhanced mechanical stability and replicated the nano-topography of native bone extracellular matrix (ECM). The AlgHA-based OS model accurately reproduced key physiological characteristics, including cell proliferation, migration, and ECM protein remodeling. Notably, the model exhibited constitutive activation of multiple signaling pathways, such as PI3K-Akt, MAPK, and calcium signaling, which may be associated with malignant phenotypes. A comparative analysis of transcriptomic profiles and drug responses between 2D cultures and the AlgHA model has identified key pathways implicated in drug resistance, such as drug metabolism-cytochrome P450 and ATP-binding cassette transporters. Additionally, potential targets including receptor tyrosine kinases and PIK3CA, which are frequently overlooked in 2D cultures, were identified. These findings underscore the utility of the micro/nano-topological AlgHA cryogel as a physiologically relevant model for OS, facilitating mechanistic studies, therapeutic target identification, and drug sensitivity prediction. And this model presents a promising platform for advancing OS treatment strategies.