Biofabrication of a Tri-layered 3D-Bioprinted CSC-based Malignant Melanoma Model for Personalized Cancer Treatment.

Conventional in vitro cancer models do not accurately reproduce the tumor microenvironment, so 3D-bioprinting represents an excellent tool to overcome their limitations. Here, two multicellular tri-layered malignant melanoma (MM) models composed by cancer stem cells isolated from a MM established cell line or a primary-patient derived cell line, fibroblasts, mesenchymal stem cells, and endothelial cells, embedded within an agarose-collagen type I hydrogel were bioprinted. Embedded-cells showed high proliferation and metabolic activity, and actively remodeled their TME. MM hydrogels displayed similar rheological properties that skin and were able to support an early onset of vascularization. Besides, MM hydrogels displayed different response to vemurafenib compared with cell cultures, and supported tumorigenesis in murine xenotransplant achieving more mimetic in vivo models. For the first time a tri-layered 3D-bioprinted CSC-based human MM model is developed recreating TME in vitro and in vivo and response to treatment, being useful for precision treatment regimens against MM.