Regenerated protein fibers. I. Research and development of a novel solvent for silk fibroin

Matsumoto, Kiyoichi; Uejima, Hiroyuki

doi:10.1002/(sici)1099-0518(19970730)35:10<1949::aid-pola9>3.0.co;2-i

Cited by 17 publications

(6 citation statements)

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“…Based on overall hydropathy of silk fibroin (in the absence of the nanophase-separated, folded molecular arrangement), water could be considered as a poor solvent for this protein. For example, viscoelastic characterization of silk fibroin solutions in LiBr$H 2 O/H 2 O/C 2 H 5 OH mixed solvents showed that the solution dynamic viscosity and flow activation energy decrease, while dissolution time and the concentration of LiBr necessary to dissolve silk fibroin increase with increasing water content, suggesting that water acts as the poor solvent in this solvent system (39,40). Therefore, a shear-induced hydrogelation mechanism analogous to that proposed for polymers in poor solvents and amphiphilicassociating polymers could be operational in the vortexinduced hydrogelation of the silk fibroin.…”

Section: Possible Hydrogelation Mechanismmentioning

confidence: 87%

Vortex-Induced Injectable Silk Fibroin Hydrogels

Yücel

Cebe

Kaplan

2009

Biophysical Journal

325

251

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A novel, to our knowledge, technique was developed to control the rate of beta-sheet formation and resulting hydrogelation kinetics of aqueous, native silk solutions. Circular dichroism spectroscopy indicated that vortexing aqueous solutions of silkworm silk lead to a transition from an overall protein structure that is initially rich in random coil to one that is rich in beta-sheet content. Dynamic oscillatory rheology experiments collected under the same assembly conditions as the circular dichroism experiments indicated that the increase in beta-sheet content due to intramolecular conformational changes and intermolecular self-assembly of the silk fibroin was directly correlated with the subsequent changes in viscoelastic properties due to hydrogelation. Vortexing low-viscosity silk solutions lead to orders-of-magnitude increase in the complex shear modulus, G*, and formation of rigid hydrogels (G* approximately 70 kPa for 5.2 wt % protein concentration). Vortex-induced, beta-sheet-rich silk hydrogels consisted of permanent, physical, intermolecular crosslinks. The hydrogelation kinetics could be controlled easily (from minutes to hours) by changing the vortex time, assembly temperature and/or protein concentration, providing a useful timeframe for cell encapsulation. The stiffness of preformed hydrogels recovered quickly, immediately after injection through a needle, enabling the potential use of these systems for injectable cell delivery scaffolds.

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Section: Possible Hydrogelation Mechanismmentioning

confidence: 87%

Vortex-Induced Injectable Silk Fibroin Hydrogels

Yücel

Cebe

Kaplan

2009

Biophysical Journal

325

251

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“…As shown in Figure a, the sericins were removed in 0.5 wt % Na 2 CO 3 solution at 100 °C for 30 min, and the degummed silk fibers were then washed with distilled water and dried at 50 °C. Recently, several special solvents [such as CaCl 2 –EtOH–H 2 O, , Ca(NO 3 ) 2 –MeOH (with and without deionized water), , LiBr–EtOH (with and without deionized water), , and LiBr–H 2 O solutions have been reported for preparing regenerated silk fibroin solutions from B. mori silk, and the most commonly used solvent is CaCl 2 –EtOH–H 2 O solution.…”

Section: Experimental Sectionmentioning

confidence: 99%

“…2a, the sericins were removed in 0.5 wt % Na 2 CO 3 solution at 100 °C for 30 min, and the degummed silk fibers were then washed with distilled water and dried at 50 °C. Recently, several special solvents [such as CaCl 2 −EtOH−H 2 O, 18,19 Ca(NO 3 ) 2 −MeOH (with and without deionized water), 20,21 LiBr−EtOH (with and without deionized water), 21,22 and LiBr−H 2 O solutions 23 have been reported for preparing regenerated silk fibroin solutions from B. mori silk, and the most commonly used solvent is CaCl 2 −EtOH−H 2 O solution. Therefore, the degummed silk fibers were dissolved in CaCl 2 − EtOH−H 2 O (mole ratio of CaCl 2 , absolute ethanol, and deionized water is 1:2:8) solution at 80 °C, for obtaining the regenerated B. mori silk fibroin solutions.…”

Section: Introductionmentioning

confidence: 99%

Bioinspired Radiative Cooling Structure with Randomly Stacked Fibers for Efficient All-Day Passive Cooling

Yang

Zhang

2021

ACS Appl. Mater. Interfaces

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Without the help of compression-based cooling systems, natural creatures have to make use of other things to decrease their body temperature to survive under thermally harsh conditions. This work finds that the silkworm cocoon of Bombyx mori protects pupae from the rapid temperature fluctuations via the randomly stacked silk fibers, which possess high solar reflectance and thermal emittance for thermal regulation. Inspired by this microstructure, the melt-blown polypropylene (MB-PP) with randomly stacked fibers is fabricated by a large-scale melt-blown fabrication method. For enhancing the thermal emittance of MB-PP, the surface-modified MB-PP (SMB-PP) is obtained by constructing the poly(dimethylsiloxane) film on the MB-PP. As the reason for its high solar reflectance (∼95%) and thermal emittance (∼0.82), the SMB-PP displays subambient temperature drops of 4 °C in the daytime and 5 °C in the nighttime, respectively. Moreover, building energy simulation indicates that the SMB-PP could save ∼132 GJ (∼58.1% of the baseline energy consumption) for 1 year in the contiguous United States. Overall, the bioinspired structures offer a novel pathway out of cooling buildings, showing great promising application prospects in zero-energy buildings.

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“…Scientists used concentrated sulphuric, hydrochloric or nitric acids to dissolve the fibers (Sonthisombat and Peter 2004). Moreover, different ionic liquids including LiBr (Chen et al 2001), CaCl 2 or Ajisawa’s reagent (Liang and Hirabayashi 1992), calcium nitrate in methanol (Mathur et al 1997), aqueous lithium bromide and ethanol (Matsumoto and Uejima 1997; Matsumoto et al 1997), aqueous lithium thiocyanate (Agarwal et al 1997) and aqueous sodium thiocyanate (Sun et al 1997) were reported.…”

Section: Introductionmentioning

confidence: 99%

Influence of the protocol of fibroin extraction on the antibiotic activities of the constructed composites

2015

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The effect of the solvents for silk fibroin (SF) extraction on its antimicrobial activity was studied. Extraction protocols were performed using LiBr (SFL) and Ajisawa’s reagent (CaCl2:ethanol:H2O) (SFC). The morphological and structural characteristics of the extracted SF and their composites were assessed. Corresponding bactericidal activities against Staphylococcus aureus (ATCC 25923), Escherichia coli (ATCC 25922) and Pseudomonas aeroginosa (ATCC 27853) were performed. The resulting solutions were either casted into films or individually incorporated into composites of silver nanoparticles (NS) embedded into chitosan fragments (Cs) through γ-irradiation. Films of SF, obtained by using the two solvents, as well as the final prepared composites of SF, NS and Cs were analyzed using XRD, FTIR, SEM, TEM and zeta potential at several pH values. The band gap values were calculated. The results proved that, although SFC consumed shorter gelation time, yet SFL exerted higher antibiotic activity against the tested microorganisms. Moreover, the final composites had the ability to significantly reduce the growth of these medically relevant bacteria and are, therefore, recommended as a novel natural antibacterial biomaterial for several biomedical applications.

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Regenerated protein fibers. I. Research and development of a novel solvent for silk fibroin

Cited by 17 publications

References 0 publications

Vortex-Induced Injectable Silk Fibroin Hydrogels

Vortex-Induced Injectable Silk Fibroin Hydrogels

Bioinspired Radiative Cooling Structure with Randomly Stacked Fibers for Efficient All-Day Passive Cooling

Influence of the protocol of fibroin extraction on the antibiotic activities of the constructed composites

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