最近对于骨肉瘤和基质硬度的相关研究主要在2D环境下进行，这与体内环境有一定区别。因此，2D模型所得结果可能无法真实反映基质硬度对细胞表型的影响。在本研究中，我们使用3D生物打印的骨肉瘤模型来研究基质硬度对骨肉瘤细胞的影响。通过调整GelMA的密度，我们构建了三个不同基质硬度（50、80和130 kPa）的骨肉瘤模型。研究结果显示，在较软的3D基质中，骨肉瘤细胞的增殖速度更快，迁移能力更强，细胞形态更拉伸，并且对药物敏感性较低。当置于较硬的基质中时，骨肉瘤细胞会分泌更多MMP和VEGF，可能是为了生存和吸引血管入侵。转录组分析显示，基质硬度可能影响整合素α5-MAPK信号通路。将3D打印模型移植到裸鼠体内的实验结果显示，封装在较软的水凝胶中的细胞更容易形成皮下肿瘤。这些结果表明基质硬度在3D环境中对于骨肉瘤的发展起着重要作用，并且抑制整合素α5可能会阻断基质硬度的信号传导。版权所有 © 2023. 由Elsevier B.V.出版。

Recent studies on osteosarcoma and matrix stiffness are still mostly performed in a 2D setting, which is distinct from in vivo conditions. Therefore, the results from the 2D models may not reflect the real effect of matrix stiffness on cell phenotype. Here, we employed a 3D bioprinted osteosarcoma model, to study the effect of matrix stiffness on osteosarcoma cells. Through density adjustment of GelMA, we constructed three osteosarcoma models with distinct matrix stiffnesses of 50, 80, and 130 kPa. In this study, we found that osteosarcoma cells proliferated faster, migrated more actively, had a more stretched morphology, and a lower drug sensitivity in a softer 3D matrix. When placed in a stiffer matrix, osteosarcoma cells secrete more MMP and VEGF, potentially to fight for survival and attract vascular invasion. Transcriptomic analysis showed that matrix stiffness could impact the signaling pathway of integrin α5-MAPK. The transplantation of 3D printed models in nude mice showed that cells encapsulated in the softer hydrogel were more likely to form subcutaneous tumors. These results suggest that matrix stiffness plays an important role in the development of osteosarcoma in a 3D environment and that inhibition of integrin α5 could block the signal transduction of matrix stiffness.Copyright © 2023. Published by Elsevier B.V.