Polymer Degradation and Stability |  April 12, 2018

Stabilization of recombinant spider silk in thermo-oxidative degradation: High-throughput screening for antioxidants

Authors:Anh T.N. Dao1, Junichi Shimokata1,2, Kengo Takeuchi1,2, Koyuru Nakayama1, Toshiaki Taniike1

DOI: 10.1016/j.polymdegradstab.2018.04.018

  • 1. Graduate School of Advanced Science and Technology, Japan Advanced Institute of Science and Technology
  • 2. Spiber Inc.

Abstract

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.

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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.