The key to the further development of silk as a preferred material for medical applications is to understand the structure and dynamics of Bombyx mori silk fibroin (SF) in the hydrated state and the characteristics of associated water. In this work, the effect of water on the structure and dynamics of 13C labeled SF fiber was revealed through the use of several 13C solid-state NMR techniques. The mobile and immobile components of SF in the hydrated state could be analyzed selectively by 13C refocused-INEPT NMR and 13C CP/MAS NMR, respectively. The fractions of several different structures in the hydrated state were also determined by 13C DD/MAS NMR spectra. In addition, the dynamics of water molecules interacting with SF was studied by 2H solution NMR relaxation and exchange measurements. Using an inverse Laplace transform algorithm, we were able to identify four distinct components in the 2H relaxation times for water in SF fiber-water system (Figure). Our measurements provide new insights relating to the hydration structure of silk and the characteristics of water, which are relevant in light of current interest in the design of novel silk-based biomaterials.

Effect of water on the structure and dynamics of [3-13C] Ser, [3-13C] Tyr and [3-13C] Ala-Bombyx mori silk fibroin studied with13C solid-state NMR

255th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.