TY - JOUR
T1 - Effects of silk degumming process on physicochemical, tensile, and optical properties of regenerated silk fibroin
AU - Nultsch, Kira
AU - Bast, Livia K.
AU - Näf, Muriel
AU - Yakhlifi, Salima El
AU - Bruns, Nico
AU - Germershaus, Oliver
PY - 2018/12/31
Y1 - 2018/12/31
N2 - Sericin removal from silk (degumming) affects material characteristics of silk fibroin (SF). Sodium carbonate is most commonly used for degumming, but numerous alternative methods are available. Herein, a systematic comparison of degumming methods is provided. Sodium carbonate, sodium oleate, trypsin, and ionic liquid are used, and materials are characterized regarding mass loss, SF content, molecular integrity of SF, refractive index, and tensile properties. Complete degumming is achieved within 30 min of using sodium carbonate, but results in significant reduction of molecular weight, shift toward less acidic charge variants, and reduction of yield- and rupture force. Sodium oleate and trypsin are inefficient and negatively affect tensile properties, while ionic liquid shows good efficiency and marginal degradation of SF but also reduced yield- and rupture force. Refractive index is not affected by degumming. These results allow rational selection of the degumming method and tuning of SF properties for biomedical applications.
AB - Sericin removal from silk (degumming) affects material characteristics of silk fibroin (SF). Sodium carbonate is most commonly used for degumming, but numerous alternative methods are available. Herein, a systematic comparison of degumming methods is provided. Sodium carbonate, sodium oleate, trypsin, and ionic liquid are used, and materials are characterized regarding mass loss, SF content, molecular integrity of SF, refractive index, and tensile properties. Complete degumming is achieved within 30 min of using sodium carbonate, but results in significant reduction of molecular weight, shift toward less acidic charge variants, and reduction of yield- and rupture force. Sodium oleate and trypsin are inefficient and negatively affect tensile properties, while ionic liquid shows good efficiency and marginal degradation of SF but also reduced yield- and rupture force. Refractive index is not affected by degumming. These results allow rational selection of the degumming method and tuning of SF properties for biomedical applications.
KW - degumming
KW - refractive index
KW - silk fibroin
KW - silk sericin
KW - tensile testing
UR - http://www.scopus.com/inward/record.url?scp=85053660289&partnerID=8YFLogxK
UR - https://onlinelibrary.wiley.com/journal/14392054
U2 - 10.1002/mame.201800408
DO - 10.1002/mame.201800408
M3 - Article
AN - SCOPUS:85053660289
VL - 303
JO - Macromolecular Materials and Engineering
JF - Macromolecular Materials and Engineering
SN - 1438-7492
IS - 12
M1 - 1800408
ER -