Temperature-Controllable Hydrogels in Double-Walled Microtube Structure Prepared by Using a Triple Channel Microfluidic System.

Hydrogels in the shape of double-walled microtubes possess great potential for development into artificial human blood vessels. In this work, we have prepared temperature-responsive tubular hydrogels with selectively controllable wall diameters, by using alginate templated photopolymerization in a triple channel microfluidic device. These tubular hydrogels mimic human blood vessels because of the separate thermally active inner and passive outer walls. The different behavior of each wall leads to the expansion of the hollow center volume with increasing temperature. This temperature-based control of the hollow center volume cannot be achieved in the case of conventional hydrogel microtubes. Furthermore, through this method, the hydrogels can be modified to achieve a controllable outer diameter while maintaining the hollow center dimensions simply by changing the position of the hydrogel walls. The ability to change the layer properties of the developed system indicates that the preparation of hydrogels with various monomers is possible.