3D Bioprinted cancer microenvironments

Tumour development induces a major modification of the surrounding microenvironment through the remodelling of its architecture and composition, in turn stimulating tumour cells proliferation and healthy cell differentiation. The investigation of this complex scenario of interactions and extra cellular matrix rearrangements is often hindered with the overly simplified 2D cells culture or in vivo studies which don’t allow to dissect key aspects of the cell-cell and cell-ECM interplay. This study aims to exploit 3D bioprinting to recreate it through a simplified, yet representative model. We exploited 3D bioprinting to create spatial compartmentalization of different components of the tumour microenvironment and specific architectures, in terms of morphology, of the extracellular matrix. For this, both natural and natural modified polymers were used: pure collagen, Matrigel and methacrylate gelatin. Specifically, we used Matrigel embedding tumour cells to simulate the tumour compartment and methacrylate gelatin or collagen mixed with fibroblasts to mimick the surrounding stromal tissue. We investigated the mechanical properties of each gel, and we explored different printing strategies to optimize the fabrication of this multimaterial and multicellular structure. Moreover, we studied how collagen morphology can be controlled tuning the bioprinting parameters.