Supported Engineered Extracellular Matrices for 3D Cell Culture

Abstract

In the current shift away from 2D tissue culture polystyrene and towards 3D cell culture models, several important design criteria have yet to be considered: (1) provision of large open areas where cells can create their own niche (2) fabrication of a scaffold that is chemically and mechanically tunable and (3) presentation of proteins that mimic native extracellular matrix (ECM). Polymer scaffolds fabricated by 3D jet writing provide extensive void space for maximum cell-cell and cell-ECM interactions. This work expands on such electrospinning technologies to establish a micromanufacturing process that modulates the flow of various polymer solutions through a manifold. The resulting scaffolds contain spatially distinct domains that can be customized to exhibit specific bulk or surface properties. Such tunability is not limited to the synthetic design space. We have discovered that hydrodynamically induced fibrillogenesis can yield remarkably stable networks of protein fibrils suspended across a support or scaffold that recapitulate important structural and functional hallmarks of cell-secreted ECM. These engineered networks of fibronectin serve as a breast cancer microenvironment, making it possible to culture an unfractionated patient sample (n=14), where less than 5% are cancer cells, into a self-selected composition of differentiated cancer cells, stem-like cancer cells, and various stromal cells. An average of 40% increase in the tumor-initiating population and at least a 7-fold increase in the cancer cell population was observed after six days (n=3). This user-defined 3D cell culture platform will enable investigation into the bidirectional relationship between cells and the ECM, not just for breast cancer but a variety of diseased or healthy tissue types.