This paper describes core-shell hydrogel wires for constructing 3D heterogeneous hydrogel microstructures containing biomaterials. A core hydrogel layer contains biomaterials such as cells, and a shell hydrogel layer covers the core to realize a mechanically-robust hydrogel wire. Using this core-shell gel wires, we demonstrate a woven sheet with heterogeneous gel wires by using our stereolithographically-made weaving machine. We also fabricate a reeled-up tube-like cell-containing structure by a glass tube spindle, inspired by tools from fiber industry. We show that our core-shell gel wires and weaving methods are powerful approach to arrange heterogeneous biomaterials in three dimensions.