Mimicking the Osteosarcoma Bone Microenvironment Using MEW-Printed PCL Scaffolds.

Osteosarcoma is the most common primary malignant bone tumor, typically affecting children and adolescents during rapid growth periods. With current treatments, the five-year survival rate for metastatic or recurrent cases remains only 20-30%, highlighting the need for new therapeutic approaches and better preclinical models. Our goal is to simulate the osteosarcoma bone microenvironment using melt electrowriting (MEW)-printed polycaprolactone (PCL) scaffolds with optimized calcium phosphate formation. To achieve this, we fabricated PCL scaffolds with distinct MEW micro-architectures, including rectangular, triangular, and hexagonal designs with comparable primary fiber spacing, and investigated two calcium phosphate formation methods: natural cell-generated mineralization and direct calcium phosphate cement coating. Using SaOS-2 osteosarcoma cells, we systematically evaluated cell behavior, mineralization dynamics, and scaffold mechanical properties. This approach aims to establish a biomimetic 3D model that bridges the gap between laboratory findings and clinical applications, enabling more pathophysiologically relevant drug testing platforms.