Biomimetic core-shell breast cancer models using alginate, gelatin, and collagen I: simulating the tumor matrix for drug evaluation.

Breast cancer remains among the most prevalent cancers in women worldwide. During tumor development, the extracellular matrix is altered to support tumor progression and therapy resistance. Therefore, there is a need to develop breast cancer models that replicate the complex tumor extracellular matrix to accurately mimic the mechanisms by which it influences drug resistance and cancer cell malignancy. In this study, we fabricated an innovative breast cancer 3D in vitro model consisting of core-shell hydrogel beads from alginate, gelatin, and collagen I by extrusion through a coaxial needle. Breast cancer cells proliferated in the core of all prototypes designed, forming spheroids and cell aggregates with a high resistance to doxorubicin. The addition of Collagen I to the developed model enabled the upregulation of malignancy markers (Col1A1, Ki67, FOXC2, SNAI1, NFKB1, WWTR1), invasion markers (WASL, ACTA1, MYO1E, TPM4, PODXL, ITGA2, ITGA5, MENA, EGFR, CDC42), and drug resistance markers (ABCG2, CYP1A1, BAX, HSP90AA1) occurring in vivo. The developed 3D in vitro model can clarify the contribution of the extracellular matrix to the tumor outcome and drug efficacy by replicating some key characteristics of breast tumors, establishing a novel tool for chemotherapeutic agents and drug screening.