Simple Fabrication of Multicomponent Heterogeneous Fibers for Cell Co‐Culture via Microfluidic Spinning

Microfluidic spinning, as a combination of wet spinning and microfluidic technology, has been used to develop microfibers with special structures to facilitate cell 3D culture/co-culture and microtissue formation in vitro. In this study, a simple microchip-based microfluidic spinning strategy is presented for the fabrication of multicomponent heterogeneous calcium alginate microfibers. The use of two kinds of microchip enables the one-step preparation of multicomponent heterogeneous microfibers with various arrangement patterns, including the preparation of one-, two-, and three-component microfibers by a two-layer microchip and preparation of four component microfibers with different arrangement by a membrane-sandwiched three-layer microchip. The obtained microfibers could be used to encapsulate various kinds of cells, such as the human non-small cell lung cancer cell NCI-H1650, the human fetal lung fibroblast HFL1, the normal pulmonary bronchial epithelial cell 16HBE, and human umbilical vein endothelial cells. By adding chitosan to the medium to keep the fibers stable, 3D long-term in vitro cell co-culture has been carried out up to 21 days. This method is very simple and easy to operate, continuously produces spatially well-defined heterogeneous microfibers, has important applications for composite functional biomaterials, and shows great potential in organs-on-a-chip and biomimetic systems.