An Artificial Phase-Transitional Underwater Bioglue with Robust and Switchable Adhesion Performance.

Complex coacervation enables important wet adhesion processes in natural and artificial systems. However, existed synthetic coacervate adhesives show limited wet adhesion properties, non-thermoresponsiveness, and inferior biodegradability, greatly hampering their translations. Herein, by harnessing supramolecular assembly and rational protein design, we present a temperature-sensitive wet bioadhesive fabricated through recombinant protein and surfactant. Mechanical performance of the bioglue system is actively tunable with thermal triggers. In cold condition, adhesion strength of the bioadhesive was only about 50 kPa. By increasing temperature, the strength presented up to 600 kPa, which is remarkably stronger than other biological counterparts. This is probably due to the thermally triggered phase transition of the engineered protein and the formation of coacervate, thus leading to the enhanced wet adhesion bonding.