posted on 2019-05-02, 00:00authored byYingjie Hang, Jie Ma, Siyuan Li, Xiaoyi Zhang, Bing Liu, Zhaozhao Ding, Qiang Lu, Hong Chen, David L Kaplan
Chemical
modifications used with silk materials can be challenging due to heterogeneous
reactions, in part due to the assembly state of the protein chains.
Here, we assess factors that determine the efficiency of chemical
modifications with silk materials. Unlike other natural macromolecules,
silk presents changeable self-assembled or aggregation states in aqueous
solution, which affect the chemical reactions based on reactive group
distribution or accessibility. To confirm this hypothesis, silk nanofibers
in various conformation and aggregation states in solution were exposed
to the same reaction conditions. Amorphous silk nanofibers provided
improved control for consistent chemical modification outcomes, while
silk nanofibers with control of structure could be utilized to generate
bifunctional materials through multiple chemical modifications. The
results of the chemical modifications demonstrated that control of
the conformational transitions of silk nanofibers provided a feasible
strategy for developing multifunctional silk materials with improved
chemical outcomes.