Tissue-Like Scaffolds Created by Two-Photon Polymerization for Testing Cancer Cell Behavior in Confined Environments

Cancer cell behavior in confined spaces is strongly related to cell-specific morphological deformations, which further influence the migration and invasion mechanisms during cancer metastasis processes. It is of great interest to create extracellular matrix-like environments with biomimetic physical properties that will be used as scaffold models to test cancer cell invasive potential. Herein, we applied two-photon polymerization to create tissue-like poroelastic scaffolds with narrow confined pores in polymeric materials. Three-dimensional (3D) scaffolds with woodpile-like geometries were fabricated in a photosensitive resist (SU-8), with various pore sizes, down to submicrometer dimensions, and covered with collagen. The quantitative analysis of cancer cell adhesion and invasive potential within the scaffolds were performed by fluorescence microscopy imaging of the cellular nuclei, cytoskeleton, and focal adhesion points. We found that melanoma cancer cell affinity to the scaffolds was two times higher when the collagen coating was applied. Additionally, the collagen coating provided much denser and stronger focal adhesion contacts that anchored cells onto the borders and inside the scaffolds, as compared to non-coated structures. Further, a larger spreading area and a higher mean migration velocity were found for melanoma cells grown on collagen-coated samples, which were correlated with cell invasive behavior on 3D scaffolds.