Time-resolved structural investigation of regenerated silk fibroin nanofibers treated with solvent vapor.
Nonwoven matrices of silk fibroin (SF) nanofibers were prepared by electrospinning a regenerated SF solution, followed by treatment with solvent vapor including water, methanol, ethanol, and propanol. Structural changes of solvent vapor-treated SF nanofibers were investigated in a time-resolved manner using IR spectroscopy. Conformational transitions of SF nanofibers from random coil to beta-sheet forms were dependent on the type of solvent vapor used, and their transition rates were strongly influenced by treatment temperatures. Consistent with previous findings, methanol vapor treatment provided a fast and effective means by which to alter the secondary structure of SF nanofibers. However, treatment with water vapor, as compared to treatment with alcohol vapor, was also useful for inducing structural changes in SF nanofibers. As demonstrated in the present study, our approach of controlling secondary structure formation of proteins by solvent vapor treatment and monitoring real-time conformational changes may be useful for the design and tailoring of materials for biomedical applications.
Department of Textile Engineering, College of Engineering, Chungnam National University, Daejeon 305-764, South Korea.
Lim
L
Jeong
Kuen Yong
KY
Lee
Ju Whan
JW
Liu
Won Ho
WH
Park
D000433:1-Propanol / Q000494:pharmacology*; D000818:Animals; D012831:Bombyx; D000431:Ethanol / Q000494:pharmacology*; D005349:Fibroins / Q000032:analysis / Q000187:drug effects* / Q000648:ultrastructure; D005740:Gases / Q000494:pharmacology; D006860:Hydrogen Bonding; D000432:Methanol / Q000494:pharmacology*; D008855:Microscopy, Electron, Scanning; D049329:Nanostructures / Q000032:analysis* / Q000737:chemistry; D019906:Nuclear Magnetic Resonance, Biomolecular; D011487:Protein Conformation / Q000187:drug effects; D017433:Protein Structure, Secondary; D047011:Silk / Q000737:chemistry; D012997:Solvents / Q000494:pharmacology*; D013055:Spectrophotometry, Infrared; D013997:Time Factors; D014835:Volatilization; D014867:Water / Q000494:pharmacology*
D005740:Gases; D047011:Silk; D012997:Solvents; D014867:Water; D000431:Ethanol; D005349:Fibroins; D000433:1-Propanol; D000432:Methanol