Microfabricated complex hydrogel fibers for quantitative evaluation of cancer cell invasion in in vivo tissue-like environments

A system for quantitatively evaluating cancer cell invasion in 3-dimensional microenvironment has been proposed, utilizing anisotropically-patterned hydrogel microfibers having soft and solid regions. Microfluidic devices composed of micromachined PMMA plates were fabricated, which were used for synthesizing the cell-encapsulating hydrogel microfibers. Cancer cells were encapsulated in the core of the fiber, whereas normal cells were seeded in the surrounding shell regions. Cancer cells proliferated through the soft shell region of the fiber, because the proliferation direction was precisely regulated by the solid shell regions. Quantitative analysis of cancer cell invasion was possible by counting the number of cancer cell colonies growing out of the fiber. We successfully examined the effect of the fibroblasts on the proliferation ability of lung cancer cells, and also evaluated the effect of anticancer drugs. The presented microfabricated hydrogel fibers would be useful for studying cell migration in 3D coculture conditions and for conducting drug screening assays.