In Vitro Osteosarcoma Models Based on 3D-Printed Composite Scaffolds to Reveal Cellular Responses, Molecular Mechanisms and Predictive Biomarkers

Osteosarcoma (OS) is the most diagnosed bone tumor in children, and current in vitro methods (2D cell culture and tumor spheroids) cannot appropriately reflect the real extracellular matrix of OS. Here, three subtypes of in vitro OS models were fabricated based on 3D-printed composite scaffolds consisting of hydroxyapatite and β-tricalcium phosphate with different ratios. The phenotypes of cell proliferation, morphology, migration, and epithelial-mesenchymal transition progression were investigated. Compared with ordinary methods, the scaffold-based OS models obtained the obvious advantage of inducing fatty acid biosynthesis, synthase expression, and classic signaling pathway. The metabolomic analysis revealed that the most abundant metabolites appeared in the type of lipids, and the metabolic differences mainly came from biosynthesis of unsaturated fatty acids. The comparison with clinical trials indicated the scaffold-based model as a potential alternative platform to discover OS pathogenesis mechanisms and to develop novel diagnosis methods that would be otherwise missed in ordinary ways.