Fabrication of thermoresponsive gel blocks using hysteresis for cell assembly

In this paper, we propose a new method to assemble microstructures made of a thermoresponsive gel using hysteresis character of the thermoresponsive polymer solution. This method can be used for 3 dimensional cell assembly by embedding cells in the thermoresponsive gel structures. Gel blocks can be maintained the gel condition by the hysteresis and the microstructures can be formed by assembling the gel blocks. The temperature distribution around the microheater was analyzed to avoid thermal damages to cells. The generation of thermoresponsive gel is conducted using the microheater which is manipulated by a micromanipulator. The fabrication of a gel block was conducted using the hysteresis character and cells were embedded in the gel. The positioning of the gel blocks can be precisely controlled by the micromanipulator. The results indicate the method we propose has a great possibility to achieve 3D cell assembly without large stress to cells during the assembly and cell culture.