In this research, we fabricated toroidal cell structures inside a microfluidic device for tissue engineering applications. A photo-crosslinkable biodegradable hydrogel gelatin methacrylate (GelMA) was employed to encapsulate biological cells for assembling cell structures. To stabilize the unstable GelMA manufacturing method,we review the manufacturing method and searched for a method that can be stavly produced. So changing the diakysis method,It was possible to prepare GelMA which is suitable as a cell culture medium. RLC-18 cells grow up on the micro structure. And when RLC-18 cells grow up,GelMA was gradually reduced
