Development and characterisation of 3D collagen-gelatin based scaffolds for breast cancer research.

While 2D culture presents a useful tool for cancer research, it fails to replicate the tumor microenvironment as it lacks proper three-dimensional cell-cell/cell-matrix interactions, often resulting in exaggerated responses to therapeutic agents. 3D models that aim to overcome the issues associated with 2D culture research offer a new frontier for cancer research with cell growth, morphology and genetic properties that more closely match in vivo cancers. Herein, we aim to develop a collagen-based scaffold that supports the attachment and proliferation of breast cancer (BC) cells as a 3D culture model. Scaffolds were produced on a repeatable basis using a freeze-drying procedure. The constructs were highly porous (>99%) with homogenous pore sizes (150-300 μm) and an interconnected structure. The application of 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDAC) crosslinking resulted in scaffolds with elastic moduli in the range of 1-2 kPa, mimicking cancerous breast tissue stiffness. Furthermore, the incorporation of gelatin into the scaffolds enabled the porosity, pore size and mechanical properties to be tailored, resulting in scaffolds with stiffness values that accurately replicate the stiffness of human BC extracellular matrix (ECM) (1.3-1.7 kPa). Scaffolds displayed high in vitro stability with 90% of mass remaining after 14 days of culture. The scaffolds were shown to be highly biocompatible, and capable of supporting the attachment, infiltration and proliferation of MCF7 breast cancer (BC) cells over +14 days. These results confirm the suitability of these scaffolds as culture models for BC cells. These collagen-based scaffolds offer significant potential for the exploration of aspects of BC, such as gene expression profiles and patterns, and for the assessment of the efficacy of therapeutic agents in treating BC.