Paper-based Invasion Assays for Quantifying Cellular Movement in Three-dimensional Tissue-like Structures.

To elucidate the chemical and environmental conditions that promote invasion of cancer cells, an assay is needed in which the chemical landscape of a tumor-like environment can be experimentally manipulated and probed. The three-dimensional paper-based invasion assays described here simulate poorly vascularized tissue and allow the invasion of cancerous cells to be visualized and quantified. These cultures are easy to assemble and allow multiple invasion assays to be performed in parallel. By using different materials to control gradients formed across the culture, the chemotactic potential of small molecules can be evaluated in a more representative tissue microenvironment. © 2017 by John Wiley & Sons, Inc.