One-step microfluidic spinning of collagen microfibers and their application to cell cultivation

Here we propose a simple but efficient method to produce collagen hydrogel microfibers using a microfluidic spinning system and a formation technique of collagen gels in a phosphate buffer. An aqueous solution of type I collagen was introduced into the microfluidic devices together with a phosphate buffer and distilled water. Parallel laminar flow was stably formed in the microchannel, and the collagen solution was transformed into microfibers with a uniform diameter. We examined factors affecting the fiber diameter and successfully obtained microfibers with a diameter from ~8 to ~30 μm. In addition, we confirmed that cells adhered on the surface of the microfibers and proliferated after culturing for several days. The presented method is advantageous because it enables the production of collagen microfibers under a wet condition without using complicated operations, organic solvents, or crosslinking reagents.