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1.
Tyrosinase oxidizes the tyrosyl residues in silk fibroin (SF) with oxygen, resulting in the production ofo-quinone residues. Subsequently, the inter- or intramolecular crosslinks are formed by reaction with amino groups in through
nonenzymatic process. The measurement of oxygen consumption proved that the tyrosyl residues in SF were mostly oxidized to
quinone residues by tyrosinase. The reaction mechanisms were proposed in this study and the crosslinking reaction ofo-quinone residues and the enzymatic oxidation of tyrosyl residues could be confirmed by the measurements of UV,1H-NMR and GFC. 相似文献
2.
Ping Wang Ying Zhou Li Cui Jiugang Yuan Qiang Wang Xuerong Fan Yajing Ding 《Fibers and Polymers》2014,15(10):2045-2050
Enzymatic oxidation of tyrosine side-chains in proteins could produce reactive o-quinones that might subsequently react with the primary amino groups of functional compounds, which provided a worthwhile reference for functionalization of fibrion materials. In the present work the potential for using tyrosinase to graft the bovine lactoferrin onto Bombyx mori silk fibroin was examined. Lactoferrin could adsorb onto silk fibers and covalently bind to the previous enzymatically oxidized fibroin surface. The enzyme-generated quinones in silk fibers also might cause self-crosslinking of fibroin peptides, which led to beneficial changes of silk properties. For the fabric treated with tyrosinase and lactoferrin slight improvements of dyeability and strength were obtained in comparison to the control. The combinedly treated fabric showed encouraging resistance to S. aureus and E. coli, the antibacterial activities reached to 87.0 % and 76.4 %, respectively. The durability of the antibacterial silk was noticeably higher than that of the sample treated with lactoferrin alone. 相似文献
3.
4.
We successfully prepared optically transparent silk fibroin-cellulose nanofiber (CN) composite films from solvent casting using a stable CN suspension in an aqueous silk fibroin solution. The transmittance of the silk fibroin composite films was observed by a UV-visible spectrophotometer. The secondary structural change of the silk fibroin caused by the incorporation of CNs was characterized using Fourier transform infrared spectroscopy. A tensile test was carried out to investigate the mechanical properties. The results showed that the composite film exhibited visible-light transmittance of 75 %, and its mechanical strength and Young’s modulus were increased by 44 % and 35 %, respectively, as compared to a neat silk fibroin film. 相似文献
5.
Won Ho Park Wan Shik Ha Hiraku Ito Takeaki Miyamoto Hiroshi Inagaki Yasuharu Noishiki 《Fibers and Polymers》2001,2(2):58-63
Silk fibroin (SF) was dissolved in calcium chloride/ethanol/water mixture (1/2/8 in mole ratio) at 70°C for 4 h. The dissolved
silk fibroin was regenerated by casting the dialyzed solution into the films. The films were treated with 50% aqueous solution
of methanol for different times, and their antithrombogenicity was evaluated byin vitro andin vivo tests.In vivo blood tests were made by a method of peripheral vein indwelling suture. It was found that the silk fibroin had a good anti-thrombogenicity
and an absorbability even though the polymer showed foreign body reaction. Finally, the blood compatibilty of silk fibroin
films which were subjected to structural change by the methanol treatment, was examined in connection with their interfacial
surface energy, and a correlation between these properties was found to be present. 相似文献
6.
In this research, a novel cotton fiber with a silk fibroin (SF) coating was prepared by the oxidation of a cotton thread with
sodium periodate and subsequent treatment in a solution of silk fibroin. The structures of both the oxidized cotton samples
and the SF modified cotton samples were investigated by Fourier transform infrared (FT-IR) in combination with X-ray photoelectron
spectroscopy (XPS) analysis. Other performances such as surface morphology and breaking strength were also studied. The results
indicated that the weight of the oxidized cotton samples increased during SF treatment, while that of the un-oxidized cotton
(pure cotton) samples reduced after SF treatment. Compared with the pure cotton samples, the oxidized cotton clearly showed
a characteristic absorption band at 1730 cm−1 due to the stretching vibration of the C=O double bond of the aldehyde group. After being treated with the SF solution, the
oxidized cotton fiber showed a weakened characteristic absorption band at 1730 cm−1 and a new absorption band at round 1540 cm−1, suggesting the formation of C-N bond between aldehyde groups in the oxidized cotton and primary amines in the silk fibroin.
The results were also confirmed by XPS analysis. Compared with the oxidized cotton samples, the SF treated cottons had relatively
smooth surfaces, similar breaking strength, and the improved wrinkle recovery angles. The results in this research suggest
that cotton based materials with protein coating can be achieved without using any other crosslinking agents by the method
introduced. 相似文献
7.
Weiguo Chen Zongqian Wang Zhihua Cui Zhaocheng Meng Min Huang Donghui Pan 《Fibers and Polymers》2014,15(5):966-970
This paper describes how coloration of silk can be achieved using a coupling reaction between a diazonium compound, made from Color Base Red G (C.I. 37105) and tyrosine residues in the silk protein fibroin. A pigment with an azo structure obtained from the reaction between the diazonium of Color Base Red G with p-methylphenol was synthesized and studied as a model compound for the coloration reaction. The colored materials were characterized using UV-vis, FT-Raman, FT-IR, 1H-NMR, and mass spectroscopy. Both the colored silk and the model compound gave yellow colors with absorption maxima in the region of 400 nm. The results suggest that the use of coupling reactions could be developed into a dyeing method for protein fibers or other protein materials that contain tyrosine residues. Because the chromophores are incorporated into the protein chains, such dyed silks should have good wet fastness properties. 相似文献
8.
Qian Zhou Qian Zhang Ping Wang Chao Deng Qiang Wang Xuerong Fan 《Fibers and Polymers》2017,18(8):1478-1485
Silk fibroin (SF) has the characteristic of moisture penetrability and biocompatibility. To enhance the biocompatibility of bacterial cellulose (BC), silk fibroin is grafted onto BC membrane using laccase and 2,2′,6,6′-tetramethylpiperidine-N-oxyl (TEMPO). As the model compound of BC, cellobiose is incubated with laccase/TEMPO for disclosing the mechanism of enzymatic oxidation. The structure and property of the composite membranes of SF/BC are investigated by means of FTIR, XPS, DSC, and biocompatibility analysis. The results indicate that cellobiose might react with hexamethylenediamine and form Schiff bases. The concentration of amino group in SF solution noticeably decreased after laccase/TEMPO oxidation, indicating the occurrence of self-crosslinking of SF. After enzymatic grafting of SF, the content of atomic nitrogen on BC surface was increased compared to that of the control. Meanwhile, the composite membrane of SF/BC exhibits more satisfactory biocompatibility compared to BC, and it has potential applications in biomedical fields. 相似文献
9.
Moo Kon Kim Hyo Won Kwak Hyung Hwan Kim Tae Rin Kwon So Young Kim Beom Joon Kim Young Hwan Park Ki Hoon Lee 《Fibers and Polymers》2014,15(6):1137-1145
In this study, we examined the effects of a dextran-modified silk fibroin nanofibrous mat (D-SFNM) on wound healing. To increase the hydrophilicity of silk fibroin (SF), the SF nanofibrous mat (SFNM) was modified with oxidized dextran. The D-SFNM absorbed water faster than the SFNM, and the swelling ratio was increased by approximately 80 % compared with the SFNM. An in vitro cell (NIH3T3) test revealed that fewer cells attached to the D-SFNM than the SFNM, but the proliferation of cells was not significantly affected by the presence of dextran. An in vivo wound healing test with mice indicated that the D-SFNM resulted in a good wound recovery effect similar to a commercial wound dressing material. The increased hydrophilicity of the D-SFNM might balance the moist environment at the wound site, which improves the wound healing compared with the SFNM. 相似文献
10.
We studied the key characteristics of a novel silk yarn reeled from fresh cocoons. Compared with traditional silk yarn, this novel silk yarn displayed better mechanical properties, especially in terms of a higher breaking stress and toughness, and exhibited a different surface morphology. A cross-sectional observation and the sericin content results illustrated that different sericin coatings on the silk yarn reeled from fresh cocoons surface did not improve the mechanical properties. The degumming and tensile testing analysis indicated that degummed silk fibroin of novel silk yarn is able to resist deformation and fracture better than silk fibroin of traditional silk yarn. The FTIR results revealed that the selected techniques is an important contributor to the silk fibroin mechanical properties, because novel technique brought higher percentage beta-sheet structures in novel silk yarn fibroin than traditional silk yarn. The new technique that using novel silk yarn has improved its mechanical properties and it is expected that the silk yarn with superior mechanical properties could be used in fabrics transistors, electrodes and reinforced biomaterials. 相似文献
11.
The tussah silk fibroin (TSF) nanofibers with 611 nm diameters were prepared by electrospinning with the solvent hexafluoroisopropanol (HFIP). And then, the TSF nanofibers were crosslinked by 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide/N-Hydroxysuccinimide (EDC/NHS) crosslinking agent. The morphology and microstructure of the crosslinked TSF nanofibers were characterized by scanning electron microscopy (SEM), Fourier transforms infrared analysis (FTIR), X-ray diffraction, Instron electronic strength tester, and cell culture. After treatment with EDC/NHS crosslinking agent, the TSF nanofibers swelled and its average diameter increased from 611 to 841 nm. FTIR and X-ray diffraction results demonstrated that random coil, ??-helix, and ??-sheet co-existed in the TSF nanofiber mats, but the content of ??-sheet increased from 25.26 to 45.34 %, and the random coil content decreased from 32.47 to 24.94 %. Compared with the electrospun pure TSF nanofiber mats, the crosslinked TSF nanofiber mats exhibited a lower breaking tenacity and initial modulus, which were 5.51 MPa and 9.86 MPa, respectively. At the same time, the extension at break of the crosslinked TSF nanofiber achieved 109.38 %. In cell culture evaluation, the crosslinked TSF nanofibers were found to support cell adhesion and spreading fibroblast L373 and bone marrow mesenchymal stem cells (BMSCs), which had potential utility in a range of tissue engineering. 相似文献
12.
Chromophore incorporated into the protein chains through residue modification on silk fibroin will be an important way to get new dyeing technology with improved color fastness. Herein, 1-aminoanthraquinone diazonium salt was prepared and used for the modified dyeing on tyrosine of silk fibroin. The silk after modified dyeing was measured by UV-Vis, FTIR, MS, 1H-NMR, Data color, and other testing techniques. Interestingly, the resulting silk showed excellent rub and wash fastness. The enhanced color fastness is contributed by an electrophilic substitution reaction between 1- aminoanthraquinone diazonium salt and the ortho position of phenolic hydroxyl in tyrosine molecular. Moreover, the mechanical property of silk was protected effectively by the mild coupling modified dyeing, better than the traditional acid dyeing under high temperature for a long time. This facile strategy provides an alternative approach to silk dyeing and benefits the silk applications. 相似文献
13.
Natalia Marchesan Bexiga Antonio Carlos Bloise Mariana Agostini de Moraes Attilio Converti Marisa Masumi Beppu Bronislaw Polakiewicz 《Fibers and Polymers》2017,18(1):57-63
The use of natural resources, especially processing wastes, as low cost and environmentally friendly alternative aiming high value-added applications is a subject of broad interest. Since the Brazilian silk production annually generates a large amount of waste during the silk fibers processing, this work explores the preparation and characterization of silk fibroin hydrogels using spinning waste silk fibers from textile processing and the processed ones. Hydrogels were obtained directly by dialyzing silk fibroin solutions against frequent changes of water until the gelation point and then lyophilized and characterized in terms of their morphology, crystallinity, thermal resistance and secondary structure. X-ray diffraction analysis revealed the presence of β-sheet conformation related to sol-gel transition. FT-IR spectra indicated the coexistence of random coil (silk I) and β-sheet (silk II) structures, with predominance of β-sheet conformation for hydrogels from processed silk fibers. From thermogravimetric analysis the presence of β-sheet secondary conformation was demonstrated by a degradation peak around 292 °C for both hydrogels. Freeze-dried hydrogels presented sheet or leaf like morphology and no significant change was observed among the hydrogels from waste silk fibers and processed ones. These characteristics suggest that silk fibroin hydrogels prepared from spinning waste silk fibers and obtained directly by dialysis can be potential candidates for biomaterials application, such as drug delivery systems and for wound dressings. 相似文献
14.
Protein concentration, pH, the types and concentrations of metallic ions, and extensional flow are thought to be important environment parameters affecting the natural spinning process. In this study, we investigate the effects of the types and concentrations of metallic ions (Ca2+, Mg2+, and K+ ions), pH, and silk fibroin concentration on the sol-gel transition and the rheological behavior of a regenerated silk fibroin (RSF) aqueous solution. The results show that with an increase in the silk fibroin concentration, the weak acidic RSF aqueous solutions containing Mg2+ or Ca2+ ions undergo a phase transition to a weak gel state. Moreover, the rheological characterization of RSF aqueous solutions shows a dramatic change, and their apparent viscosities increase by almost three orders of magnitude and approach the apparent viscosity of the native dope in the silkworm gland. By using conventional pressure equipment, we investigate the dry-spinnability of weak gels. Further, we observe that the as-spun fibers exhibit a smooth surface and have inferior mechanical properties. The structure of the as-spun fibers is predominantly in a random coil or Silk I conformation. 相似文献
15.
Herein we report successful synthesis of silk fibroin (SF) three dimensional scaffolds (SF 3D-scaffold) from SF sponge and SF nanofibers. Both the nanofibers and sponge were prepared from Bombyx mori fibroin. The SF 3D-scaffold was prepared by electrospinning the fibroin nanofibers over the sponge. Surface morphology was determined by scanning electron microscopy (SEM), while nanofiber diameter and pore size were measured using imageJ software. Effect of spinning time on the pore size and cell adhesion was determined. Average diameter of the SF nanofibers was measured to be 320 nm and pore size was found to reduce with increasing spinning time, such that, for 1 h spinning time pore size was 231 µm and the same for 3.5 h was 4.1 µm. However, the number of pores increased with spinning time. The results confirmed adhesion of MC3T3-E1 cells on the SF sponge, SF nanofibers and SF three dimensional scaffolds. Higher cell adhesion was found on the three dimensional scaffold in comparison to the nanofibers and sponge, possibly due to highly porous structure with very small and numerous pores in the resultant composite; hence more cell adhesion sites. The cell adhesion result confirmed biocompatibility of the SF 3D-scaffold and hence its suitability for applications in tissue engineering. 相似文献
16.
Ultra fine fibers were electrospun from regenerated silk fibroin/formic acid solution. Effect of some process parameters on
the morphology, diameter and variation in fiber diameter of electrospun fibers were experimentally investigated. Scanning
electron microscope was used for the measurement of fiber diameter. Fibers with diameter ranging from 80 to 210 nm were collected
depending on the solution concentration and the applied voltages. Response surface methodology (RSM) was used to obtain a
quantitative relationship between selected electrospinning parameters and the average fiber diameters and its distribution.
It was shown that concentration of silk fibroin solution had a significant effect on the fiber diameter and the standard deviation
of the fiber diameter. Applied voltage had no significant effect on the fiber diameter and its standard deviation. 相似文献
17.
Protein and polysaccharide was the most important extracellular matrix in dermal tissue. In this study, Silk fibroin (SF) / hyaluronic acid (HA) blend films mimicking the dermal tissue components were prepared and investigated. The results indicated that HA and SF has a good miscibility, HA interfered with SF to form crystal structure. By using EDC as cross-linker, effective cross-linking function on SF and HA macromolecules was reacted, the water solubility of the blend films decreased obviously after being cross-linked by EDC. The existence of EDC could promote SF to form Silk I structure. L929 cells were seeded on these blend films and showed normal attachment morphology. Cell-matrix interactions established by newly formed extracellular matrix were observed after 5 days in culture. The MTT assay showed that cell proliferation on the SF/HA blend films were enhanced significantly compared with that on the SF and HA films. These new 2D SF/HA blend films provided a favorable microenvironment for the proliferation of L929 cells and hold a potential for dermal tissue regeneration. 相似文献
18.
Ziying Wu Dun Huang Zhiwen Hu Yang Zhou Feng Zhao Zhiqin Peng Bing Wang 《Fibers and Polymers》2014,15(6):1146-1152
Consolidation of fragile historic silks is of great importance for further displays and researches. An effective and convenient method to consolidate aged silk fabric has been proposed by using a silk fibroin (SF)/ethylene glycol diglycidyl ether (EGDE) consolidation system. Artificial aged silk fabrics treated with SF/EGDE show great improvement in mechanical properties. The chemical reaction between EGDE and silk fabrics has been proved in previous paper. And in this paper, mechanical test, field emission scanning electron microscopy (FESEM), Fourier transform infrared spectrum (FTIR) test and amino acid analysis (AAA) were applied to illustrate the interactions between SF and silk fabric, EGDE and SF. Results show that SF takes part in the consolidation in the form of adhesions on the surface of silk fibers. The chemical reactions and film adhesion are both responsible for the improvements of mechanical properties in the consolidation. 相似文献
19.
Waree Tiyaboonchai Pratthana Chomchalao Sutatip Pongcharoen Manote Sutheerawattananonda Prasert Sobhon 《Fibers and Polymers》2011,12(3):324-333
The aim of this study was to compare physical, mechanical and biological properties of 3-dimensional scaffolds prepared from
Bombyx mori silk fibroin (SF), fibroin blended with collagen (SF/C), and fibroin blended with gelatin (SF/G) using a freeze-drying technique.
The prepared scaffolds were sponge-like structure that exhibited homogeneous porosity with highly interconnected pores. Average
pore size of these scaffolds ranged from 65–147 μm. All biodegradable scaffolds were capable of water absorption of 90 %.
The degradation behavior of these scaffolds could be controlled by varying the amount of blended polymer. The SF/C and SF/G
scaffolds showed higher compressive modulus than that of SF scaffolds which could be attributed to the thicker pore wall observed
in the blended constructs. The less crystalline SF structure was observed in SF/G scaffolds as compared to SF/C scaffolds.
Thus, the highest compressive modulus was observed on SF/C matrix. To investigate the feasibility of the scaffolds for cartilage
tissue engineering application, rat articular chondrocytes were seeded onto the scaffolds. The MTT assay demonstrated that
blending collagen or gelatin into SF sponge facilitated cell attachment and proliferation better than SF scaffolds. The blended
SF scaffolds possessed superior physical, mechanical and biological properties in comparison to SF scaffolds and showed high
potential for application in cartilage tissue engineering. 相似文献
20.
Electro-spun silk web has attracted attention for biomedical applications because of its excellent bio-compatibility and facile fabrication method. Because biomedical applications require various performances of silk web, many studies have been conducted on the effect of the variables associated with their preparation on the structure and properties of silk web. In the present study, the effect of residual sericin content on the morphology, structural characteristics, and properties of electrospun regenerated silk web was examined. The regenerated silk without sericin (i.e., silk with 100 wt% fibroin) did not show good electro-spinnability. However, the electro-spinnability improved remarkably above a sericin content of 0.6 wt%. The crystallinity index of the electro-spun silk increased at 0.6 wt% sericin content and decreased above 8.2 wt% sericin. The mechanical properties of the electro-spun silk webs showed a similar trend as their crystallinity indices. The breaking strength and elongation improved significantly at 0.6 wt% sericin content and both parameters gradually decreased above this value. The thermal stability of the silk web decreased slightly upon increasing the sericin content. 相似文献