EFFECT OF STORAGE TIME AND CONCENTRATION ON STRUCTURE OF REGENERATED SILK FIBROIN SOLUTION

Concentrated regenerated silk fibroin (RSF) aqueous solutions with concentration close to that of the native silk fibroin (15.5%, 25.5% and 31%) were prepared. The effect of storage time and concentration on the conformational transition of the concentrated RSF aqueous solution was studied by Raman spectroscopy and circular dichroism (CD) spectroscopy. At the same time, the conformational change of RSF aqueous solution in flowing state was also investigated. It was found that the conformation of silk fibroin was changed gradually from random coil/α-helix to β-sheet structure during the storage. And the conformational transformation was accelerated with the increasing of the RSF aqueous solution concentration. When the solution was in flowing state, the conformational transformation was also accelerated.