Recombinant spider silk has arisen as one of the most promising nature-derived building blocks owing to its extraordinary mechanical properties, while its instability against thermo-oxidative degradation becomes a major drawback toward industrial applications. Here, we have firstly implemented a high-throughput screening of antioxidants on the stabilization of recombinant spider silk at an elevated temperature. The usage of high-throughput chemiluminescence imaging has allowed us to screen antioxidants with a wide spectrum of molecular structures and quickly provided two good candidates to stabilize recombinant spider silk powder through an impregnation process: E310 and BHT. An accelerated aging has further proven that these antioxidants suppressed the thermo-oxidation of recombinant spider silk through scavenging the formed radical species and slowed down the formation of carbonyl groups as oxidation products. In addition, we have employed a solution mixing process to further improve the stabilization efficacy of the antioxidants and this method also extended our selection on effective antioxidants, including vitamin E, AO-30, AO-40, HP-10, and especially Irganox 1098. These screening results provide guidelines of selecting or even developing potential antioxidants for stabilizing protein materials.
Spiber’s research initiatives into novel protein materials have benefited from subsidies provided by the ImPACT Program on behalf of the Japanese Cabinet’s Council for Science, Technology and Innovation.