Comparison of Porosity Improvement of Silk Fibroin Membrane Using Polyethylene Glycol and Glutaraldehyde for Increasing Oxygen Permeability

2013 ◽  
Vol 750-752 ◽  
pp. 1601-1608
Author(s):  
Pacharawan Ratanasongtham ◽  
Ruangsri Watanesk ◽  
Surasak Watanesk

Biomaterial is one of the good candidates for porous membrane preparation according to its environmental friendliness. In this work, the porous membranes of silk fibroin (SF) were prepared by solution casting with the addition of polyethylene glycol (PEG) and glutaraldehyde (GTA) aiming to improve the porosity and oxygen permeability of SF membrane. The conformation of SF was changed from random coil to β sheet form after treatment with MeOH. The interaction existing between SF chains and both PEG and GTA were characterized using Fourier Transform Infrared spectroscopy (FT-IR). The addition of PEG could produce more porosity in the membrane than GTA confirmed by their morphology observed from scanning electron microscopy (SEM). Moreover, the swelling behavior of the SF-PEG and SF-GTA membranes depended on the porous structure of the membrane which directly correlated to their oxygen permeability. The porosity of the SF membranes increased with the increase of PEG and GTA contents up to 40% and 3%w/w, respectively. After that, their porosity decreased as seen through the SEM and water swelling results. In addition, the SF-PEG membrane turned out to have higher degrees of both porosity and oxygen permeability than the SF-GTA membrane which related to its water swelling behavior.

2013 ◽  
Vol 721 ◽  
pp. 274-277
Author(s):  
Li Li Ji ◽  
Qiao Ling Li ◽  
Zeng Hu Yang ◽  
Wei Jing Hu ◽  
Kui Hua Zhang

Vitamin E d-alpha-tocopheryl polyethylene glycol 1000 succinate (VE TPGS) loaded silk fibroin (SF)/ hyaluronic acid (HA) nanofibrous scaffolds were fabricated by means of electrospinning to biomimic the natural extracellular matrix. Scanning electronic microscopy (SEM) results indicated that electrospun VE TPGS loaded SF/HA nanofibers were ribbon-shaped, the width of nanofibers decreased slightly with the addition of VE TPGS to SF/HA blended solutions. Fourier transform infrared (FTIR) spectroscopy and Wide-angle X-ray diffraction (WAXD) curves revealed that VE TPGS did not induce SF conformation from random coil to β-sheet. SF conformation converted from random coil to β-sheet after being treated with 75% ethanol vapor. In vitro release studies confirmed VE TPGS had no obvious burst release and present good release behavior.


2011 ◽  
Vol 175-176 ◽  
pp. 176-180
Author(s):  
Hui Ying Wu ◽  
Bao Qi Zuo

Silk fibroin modified viscose fiber (SFVF) was a new fiber with silken handling and luster, which was produced via adding silk fibroin (SF) during the viscose process. In this paper, a series of testing had been done to study the structure and properties of SFVF. The amino acid content of SFVF was measured by HITACHI-835-50 amino acid tester. The morphology, structure, thermal and mechanical property of SFVF were characterized by SEM, FTIR, DSC and electronic strength tester. The results indicated that SFVF consisted of many kinds of amino acids compared with pure viscose fiber (VF) yarn. The results of SEM showed more continuous multi fine slots existed in the longitudinal section of SFVF than in that of VF, demonstrating that wet permeability and vapor transmission could be enhanced for the SFVF to certain extent. Results from FTIR indicated that the secondary structure of SFVF was mainly β-sheet and random coil, and its absorption peaks were 1616cm-1 and 1644 cm-1 respectively. The DSC curve shown the thermal decomposition temperature of SFVF was about 328.39°C, which was close to that of VF. It suggested that the SF modification had no obvious influence on thermal stability of VF. At last, the dry-strength and wet-strength of SFVF was close to that of VF. Therefore, the application of VF would be expanded with the SF modification.


RSC Advances ◽  
2015 ◽  
Vol 5 (119) ◽  
pp. 98553-98558 ◽  
Author(s):  
Chen Liu ◽  
Jiaqi Sun ◽  
Min Shao ◽  
Bin Yang

Centrifugal spinning converts the conformation of silk fibroin from random coil to β-sheet more easily than electrospinning, which results in fiber differences on secondary structures, orientation and thermal properties.


2021 ◽  
Author(s):  
Ben Jia ◽  
Lan Jia ◽  
Jingxin Zhu

Abstract In this work, the potential application of the fluorescence dye Thioflavin-T (ThT), which can specifically bind to amyloid, as a powerful tool for monitoring secondary structure transitions of silk fibroin (SF) induced by pH was examined. Results showed that ThT emission intensities substantially increased when pH decreased from 6.8 to 4.8. This increase may be due to conformational transitions from random coil to β-sheet. The morphology and secondary structure of SF were also investigated via TEM, AFM and circular dichroism spectroscopy. The information obtained herein can be utilized not only for the development of convenient and efficient noninvasive method for monitoring the assembly behavior of SF in aqueous solution but also for in vitro fluorescence imaging.


2007 ◽  
Vol 342-343 ◽  
pp. 813-816 ◽  
Author(s):  
Lim Jeong ◽  
Kuen Yong Lee ◽  
Won Ho Park

Nonwoven nanofiber matrices were prepared by electrospinning a solution of silk fibroin (SF) dissolved either in formic acid or in 1,1,1,3,3,3-hexafluoro-2-isopropyl alcohol (HFIP). The mean diameter of the electrospun nanofibers prepared from SF dissolved in formic acid was 80 nm with a unimodal size distribution, which was smaller than those prepared from HFIP (380 nm). SF nanofibers were then treated with an aqueous methanol solution, and structural changes due to solvent-induced crystallization of SF were investigated using IR and 13C solid-state CP/MAS NMR spectroscopy. SF nanofibers prepared from formic acid were found to have a higher proportion of β-sheet conformations than those prepared from HFIP. Methanol treatment provided a fast and effective means to alter the secondary structure of both types of SF nanofibers from a random coil form to a β-sheet form. As demonstrated in the present study, this approach to controlling the dimensions and secondary structure of proteins using various solvents may be useful for the design and tailoring of materials for biomedical applications, especially for tissue engineering applications.


1989 ◽  
Vol 43 (7) ◽  
pp. 1269-1272 ◽  
Author(s):  
Siding Zheng ◽  
Guanxian Li ◽  
Wenhuo Yao ◽  
Tongyin Yu

The mechanical denaturation process of silk fibroin is examined by Raman spectroscopy. The fresh silk fibroins from the middle gland of mature silkworms are drawn to various ratios on a tensile tester ( R = ldrawn/ linitial, where l is length) and their conformations are measured with Raman spectroscopy. Undrawn silk fibroin is mainly in the random coil structure with some α-helical conformation, the characteristic bands appearing at 1252 and 1660 (random coil) and at 942, 1106, and 1270 cm−1 (α-helix). When the samples are drawn up to R = 4 at an extension rate of 500 mm/min, two peaks at 1233 cm−1 (the amide III band) and 1085 cm−1 appear; it is shown that the β-sheet conformation is then formed. With an increase in drawing ratios, the intensities of these β-sheet bands increase and those of the random coil and α-helical bands decrease gradually. These changes indicate that, under the action of stress, the conformation of fibroin is altered from random coil and α-helix to β-sheet structures. This result is quite similar to the results achieved by the spinning of the silkworm. The effect of the water content in liquid silk on this conformational transition process is revealed and discussed.


Biopolymers ◽  
2014 ◽  
Vol 101 (12) ◽  
pp. 1181-1192 ◽  
Author(s):  
Jian Zhong ◽  
Mengjia Ma ◽  
Wenying Li ◽  
Juan Zhou ◽  
Zhiqiang Yan ◽  
...  

2011 ◽  
Vol 311-313 ◽  
pp. 1653-1656 ◽  
Author(s):  
Fang Xie ◽  
Hao Liang

The thermal properties and rheological behavior of concentrated regenerated silk fibroin aqueous solution from 15% to 37% was investigated by differential scanning calorimetry (DSC) and rheometer. Also the conformation of solutions was characterized by Raman spectra. It was discovered that the major endothermic peak in the DSC curves shifted toward the lower temperature region with increasing the concentration. This behavior suggests increasing the concentration can accelerate conformational transition of silk fibroin from random coil and α-helix to β-sheet structure. In addition, it was found that the viscosity of solution increased with increasing concentration in favor of spinning.


2012 ◽  
Vol 569 ◽  
pp. 311-315 ◽  
Author(s):  
Shen Zhou Lu ◽  
Li Mao ◽  
Yu Liu ◽  
Shan Sun ◽  
Gui Jun Li

Antheraea pernyi silk fibroin (ASF) solution was prepared by dissolving Antheraea pernyi silk fiber in lithium thiocyanate solution. The ASF/glycol blend films were prepared by casting aqueous solution of ASF mixed with glycol. The structure of blend film was investigated by the X-ray diffraction method and infrared spectroscopy. The result showed that the structure of regenerated ASF film was α-helix and random coil conformation. After mixing with glycol, it resulted in significant increase in β-sheet structure with the improvement of water resistance of the films. This effect was strongly dependent on glycol content in the blend film. When the glycol content was more than 45 wt%, the structure of ASF changed to β-sheet and the film became water-insoluble. The breaking strength and elongation of ASF/glycol blend film were 30 Mpa and 50 %, respectively. In summary, the ASF/glycol blend film provided a great potential as a biological material.


2013 ◽  
Vol 641-642 ◽  
pp. 910-914
Author(s):  
Shao Qun Li ◽  
Yu Bin Tang ◽  
Jun Qiang Jia ◽  
Ming Zhu Jiang ◽  
Hui Yan

Silk fibroin film (SFF) has good mechanical property, cells compatibility and biodegradability, and was widely used in the biomedical area as controlling materials. In this work, silk fibroin (SF) was obtained from cocoons. It was dissolved in distilled water to form 5 % and 8 % (W/V) SF solution, which was used to prepare 0.5 %, 1.0 % and 2 % (W/V) sulfadiazine sodium (SD) solution. Five layers of SFF was prepared with salivation method, dried under 37 °C, and annealed with 90 % (V/V) methanol. The structure information was analyzed by FT-IR and SEM, SD release in PBS (0.2 mol/L, pH 7.4) and PBS containing 2 U/ml trypsin at 37 °C was measured. The FT-IR spectra showed that more β-sheet was formed after annealed by methanol; a lot of pores were in the SFF and SD was embedded in SFF through analyzing the image of SEM. The release speed from SFF made by 5 % SF solution was faster than that from SFF made by 8 % SF solution. As for SFF containing different concentration of SD, the release rate improved with the increase of concentration of SD, however, the time of reaching the maximum were approximate. In PBS with trypsin, the time of reaching the maximum accumulative release was one hour earlier compared with in the PBS. Therefore, we draw a conclusion that the SFF incorporating SD has good properties and it has the feasibility to be used as artificial skin for burned patients.


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