TY - JOUR
T1 - Effect of processing and storage time of aqueous solutions on silk fibroin structure and methanol post-treatment of electrospun fibers
AU - Puerta, Melissa
AU - Peresin, Maria S.
AU - Restrepo-Osorio, Adriana
N1 - Publisher Copyright:
© 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.
PY - 2022/2
Y1 - 2022/2
N2 - Silk fibroin (SF) is a natural and biocompatible polymer that is obtained from silk cocoons or from silk fibrous waste. In this study, aqueous solutions of SF were obtained from silk fibrous waste (SFW) and subjected to concentration by reverse dialysis with polyethylene glycol (PEG) or freeze-drying with subsequent resolubilization prior to processing via electrospinning. The regenerated SFW was stored at 4 °C, and its stability during refrigeration was investigated in terms of structural changes using visual monitoring and attenuated total reflectance Fourier transform infrared spectroscopy (FTIR-ATR) until gelation occurred. The electrospun nonwovens produced through both concentration processes were post-treated using methanol (MeOH), by immersion in the liquid solvent and by exposure to a saturated atmosphere. The electrospun nonwovens before and after post-treatments were characterized using scanning electron microscopy (SEM), FTIR-ATR, and differential scanning calorimetric (DSC). SFW re-suspended after the PEG concentration remained liquid and retained its electrospinnability for 21 days, while the resolubilized SFW solution after freeze-drying formed a gel after only 7 days. During these processability windows, it was possible to obtain SFW homogeneous fibers. Increasing solution storage time was correlated with increased fiber diameter and reduced porosity of the electrospun nonwovens. The fibers treated with MeOH, both liquid and vapor, showed an increase in diameter and crystallinity, as well as a reduction in their apparent porosity. This work contributes new information about pre- and post-processing of SFW aqueous solutions for electrospun SFW nonwovens, expanding the potential of a by-product of silk production in value-added biomaterials production. Graphical abstract: [Figure not available: see fulltext.]
AB - Silk fibroin (SF) is a natural and biocompatible polymer that is obtained from silk cocoons or from silk fibrous waste. In this study, aqueous solutions of SF were obtained from silk fibrous waste (SFW) and subjected to concentration by reverse dialysis with polyethylene glycol (PEG) or freeze-drying with subsequent resolubilization prior to processing via electrospinning. The regenerated SFW was stored at 4 °C, and its stability during refrigeration was investigated in terms of structural changes using visual monitoring and attenuated total reflectance Fourier transform infrared spectroscopy (FTIR-ATR) until gelation occurred. The electrospun nonwovens produced through both concentration processes were post-treated using methanol (MeOH), by immersion in the liquid solvent and by exposure to a saturated atmosphere. The electrospun nonwovens before and after post-treatments were characterized using scanning electron microscopy (SEM), FTIR-ATR, and differential scanning calorimetric (DSC). SFW re-suspended after the PEG concentration remained liquid and retained its electrospinnability for 21 days, while the resolubilized SFW solution after freeze-drying formed a gel after only 7 days. During these processability windows, it was possible to obtain SFW homogeneous fibers. Increasing solution storage time was correlated with increased fiber diameter and reduced porosity of the electrospun nonwovens. The fibers treated with MeOH, both liquid and vapor, showed an increase in diameter and crystallinity, as well as a reduction in their apparent porosity. This work contributes new information about pre- and post-processing of SFW aqueous solutions for electrospun SFW nonwovens, expanding the potential of a by-product of silk production in value-added biomaterials production. Graphical abstract: [Figure not available: see fulltext.]
UR - http://www.scopus.com/inward/record.url?scp=85123250914&partnerID=8YFLogxK
U2 - 10.1007/s10853-022-06873-x
DO - 10.1007/s10853-022-06873-x
M3 - Artículo
AN - SCOPUS:85123250914
SN - 0022-2461
VL - 57
SP - 3842
EP - 3854
JO - Journal of Materials Science
JF - Journal of Materials Science
IS - 5
ER -