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Selfonation reaction may be an effective method for preparation of heparin-like materials. However, no sulfonated polymer based on protein backbone was used for improving the blood compatibility of biomaterials. In this study, the...
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Selfonation reaction may be an effective method for preparation of heparin-like materials. However, no sulfonated polymer based on protein backbone was used for improving the blood compatibility of biomaterials. In this study, the biocompatibility of new kind of composite materials films obtained by blending silk fibroin (SF) with sulfonated silk fibroin (SSF) was evaluated. The anticoagulant activity was characterized with prothrombin time (PT), activated partial thromboplastin time (APTT), and thrombin time (TT), which all increased remarkably, the clot times exceeded the measurement limit of clot detection instrument. Its platelet adhesion was also investigated as another parameter of blood compatibility. The cell compatibility of composite films was evaluated through cell morphologies on the films and cell viability by methyl thiazolyl tetrazolium (MTT) assay. Tensile strength and elongation at break of the composite films reached to 44.6 MPa and 50.3 percent, respectively. All these results indicated that SF/SSF composite film was a potential material for blood-contact materials and tissue engineering matrix.
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A novel prosthesis using silk fibroin with blending heparin and sulfonated silk fibroin was studied. Anticoagulation activities of heparin/silk fibroin and sulfonated silk fibroin/silk fibroin vascular and mechanical property resu...
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A novel prosthesis using silk fibroin with blending heparin and sulfonated silk fibroin was studied. Anticoagulation activities of heparin/silk fibroin and sulfonated silk fibroin/silk fibroin vascular and mechanical property results showed that heparin/silk fibroin and sulfonated silk fibroin/silk fibroin vascular could meet the requirement of small caliber grafts. This study indicated that silk fibroin could be used for developing tissue engineering biological vascular grafts that could use for human coronary or low extremity artery bypasses.
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Silk fibroin (SF) obtained from Bombyx mori cocoon is a very promising biopolymer. It can be processed from aqueous solutions to obtain many versatile scaffolds useful in optoelectronics, photonics, and biomedicine. Aqueous soluti...
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Silk fibroin (SF) obtained from Bombyx mori cocoon is a very promising biopolymer. It can be processed from aqueous solutions to obtain many versatile scaffolds useful in optoelectronics, photonics, and biomedicine. Aqueous solutions are prepared by dissolving degummed fibroin with chaotropic agents and then purifying by dialysis. This work presents, for the first time, a solubilization protocol, involving CeCl_3·7H_2O as chaotropic salt in water and ethanol, that allows to regenerate SF under a fibrous form, unlike the standard Ajisawa's method, which uses CaCl_2 and allows to obtain aqueous gels. All the experimental analyses performed (SEM, XPS, WAXS, ATR-FTIR, NMR) suggest that the fiber recovered preserves most of the morphological and structural features of the pristine SF and is doped with Ce(III) ions, that interact mainly with the oxygen atoms of C=O moieties and side-chains of amino acids. Ce(III) doped SF could be the base for new luminescent materials.
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The stiffness of scaffolds serving as substrates for growing cells and living tissues can be increased by using silk fiber to reinforce biopolymers. Biopolymer scaffolds for tissue engineering and regenerative medicine can be prod...
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The stiffness of scaffolds serving as substrates for growing cells and living tissues can be increased by using silk fiber to reinforce biopolymers. Biopolymer scaffolds for tissue engineering and regenerative medicine can be produced via electrospinning of fibrous materials from solutions of preliminarily degummed silk fibroin. The properties of fibroin solutions in the presence of nonsolvents and crosslinking agents, the influence of EtOH on the conformational transition in fibroin solutions, and the conditions for spinning fibers from compositions based on silk fibroin and chitosan were studied. Two methods for converting fibrous materials made of fibroin into a water-insoluble form were proposed, i.e., structural rearrangements on going to the beta-sheet conformation and chemical crosslinking by the natural reagent genipin. Water-insoluble ultrathin fibers made of fibroin, the morphology of which was confirmed by atomic force microscopy, were obtained and shown to be effective when used as scaffolds for tissue engineering.
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Biochemical modification can endow the surface of implants with superior biological activity. Herein, silk fibroin (SF) protein and its anionic derivative peptides (Cs) were covalently immobilized onto a titanium implant surface v...
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Biochemical modification can endow the surface of implants with superior biological activity. Herein, silk fibroin (SF) protein and its anionic derivative peptides (Cs) were covalently immobilized onto a titanium implant surface via a polydopamine layer. The successful conjugation of SF and Cs was revealed by X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), and contact angle measurements. The addition of Cs prevented the conformational transition of silk fibroin to silk II. The deposition of apatite on its surface was significantly accelerated, and the bioactive composite coating was observed to enhance protein adsorption and cell proliferation. More importantly, it also promoted the osteogenic differentiation of bone marrow stem cells (BMSCs) for the quantitative and qualitative detection of alkaline phosphatase (ALP) and alizarin red (ARS). Overall, the stable performance and enhanced osteogenic property of the composite coating promote an extensive application for clinical titanium-based implants.
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In this study, different concentrations of 17-β estradiol silk fibroin (SF)porous scaffolds (SFPS) were prepared using freeze-drying technique, with a hope for optimal concentration and apply it locally to the bone defect area. I...
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In this study, different concentrations of 17-β estradiol silk fibroin (SF)porous scaffolds (SFPS) were prepared using freeze-drying technique, with a hope for optimal concentration and apply it locally to the bone defect area. In this study, the porous scaffold morphology structure was characterized by SEM, FTIR and universal capacity testing machines, and the in?vitro cytocompatibility and biological activity of scaffold materials were studied by cell adhesion, viability and proliferation experiments. The results showed that SFPS boasts better physicochemical properties, while 17-β estradiol SF scaffolds with low concentrations of 10<sup>?10</sup>?mol/L and 10<sup>?12</sup>?mol/L had more growth and proliferation of SF scaffolds with higher concentrations, and 10<sup>?10</sup>?mol/L was the optimal concentration of 17-β estradiol SFPS, which was more conducive to cell adhesion and proliferation. On the other hand, after osteogenesis induction of BMSCs inoculated on 17-β estradiol SFPS at different concentrations, it was found that the expression of alkaline phosphatase in BMSCs on different concentrations of 17-β estradiol porous scaffolds was not large. No conflict of interest exits in the submission of this manuscript.
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ABSTRACT The surface roughness of silk fibroin biomaterials affects the adhesion and growth of cells on their surface. Silk fibroin molecules exhibit the natural ability to self-assemble. By utilizing this feature, a silk fibroin ...
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ABSTRACT The surface roughness of silk fibroin biomaterials affects the adhesion and growth of cells on their surface. Silk fibroin molecules exhibit the natural ability to self-assemble. By utilizing this feature, a silk fibroin film with rough surfaces can be easily prepared. Scanning electron microscopy and atomic force microscopy results showed micro-/nanoscale protrusions with a uniform distribution over the film surface. The film structure characterization and dynamic light scattering results confirmed that this is because the silk fibroin molecules self-assemble in solution to form relatively large aggregates. These aggregates penetrate the surface of the film during drying, thereby forming these tiny protrusions on the film surface. Furthermore, the results of the cell adhesion test prove that this rough surface is more conducive to cell adhesion and growth thereon.
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Membranes prepared by drying aqueous Bombyx mori silk fibroin (SF) solution and modified silk fibroin (MSF) solutions, prepared by adding the low molecular weight crosslinking agent, polyethylene glycol diglycidyl ether (PEGDE) MW...
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Membranes prepared by drying aqueous Bombyx mori silk fibroin (SF) solution and modified silk fibroin (MSF) solutions, prepared by adding the low molecular weight crosslinking agent, polyethylene glycol diglycidyl ether (PEGDE) MW 526, 0-10% w/w, were investigated by Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR) spectroscopy, and UV-vis spectroscopy. Weight gain in aqueous solutions and their mechanical properties (tensile strength, elongation, and Young's modulus) were then characterized. SEM measurements revealed greater porosity in MSF membranes. IR spectra showed transformation from the largely alpha-helical/ random coil structures in SF membranes to predominantly P-sheet in MSF membranes. Results from UV-vis spectroscopy showed that the MSF membranes were largely insoluble within the pH range of 4-10. Water absorbability of the MSF membranes improved with increasing the amounts of cross-linker, up to 4%. The MSF membranes showed greater pliability and tenacity, but lower tensile strength, with increasing PEGDE concentrations. In the wet condition, PEGDE levels up to 4% can improve both tensile strength and tenacity of the MSF membrane, but higher levels (up to 10%) did not significantly change these properties. (c) 2008 Wiley Periodicals, Inc.
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Silk, as a kind of natural fibrin, has been prepared into various biomaterials due to its excellent biocompatibility and mechanicalness. However, there are some controversies on the biocompatibility of silk fibroin (SF), especiall...
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Silk, as a kind of natural fibrin, has been prepared into various biomaterials due to its excellent biocompatibility and mechanicalness. However, there are some controversies on the biocompatibility of silk fibroin (SF), especially when it coexists with sericin. In this study, two kinds of silk from Jiangsu and Zhejiang were degummed with two concentrations of Na 2 CO 3 solution, respectively, to obtain four kinds of silk fibroin. The effects of different degumming treatments on silk fibroin properties were analyzed by means of color reaction, apparent viscosity measurement, and transmission electron microscope and isobaric tags for relative and absolute quantification analyses, and the effects of different silk fibroin membranes on the growth of Schwann cells were evaluated. The results showed that the natural silk from Zhejiang treated with 0.05% Na 2 CO 3 solution had a fuller structure, higher apparent viscosity, and better protein composition. While SF obtained by degumming with 0.5% Na 2 CO 3 solution was more beneficial to cell adhesion and proliferation due to the thorough removal of sericin. This study may provide important theoretical and experimental bases for the selection of biomaterials for fabricating artificial nerve grafts.
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Previously, we have described the preparation of a novel fibroin methacrylamide (FbMA), a polymer network with improved functionality, capable of photocrosslinking into Fb hydrogels with elevated stiffness. However, it was unclear...
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Previously, we have described the preparation of a novel fibroin methacrylamide (FbMA), a polymer network with improved functionality, capable of photocrosslinking into Fb hydrogels with elevated stiffness. However, it was unclear how this new functionality affects the structure of the material and its beta-sheet-associated crystallinity. Here, we show that the proposed method of Fb methacrylation does not disturb the protein's ability to self-aggregate into the stable beta-sheet-based crystalline domains. Fourier transform infrared spectroscopy (FTIR) shows that, although the precursor ethanol-untreated Fb films exhibited a slightly higher degree of beta-sheet content than the FbMA films (46.9% for Fb-F-aq and 41.5% for FbMA-F-aq), both materials could equally achieve the highest possible beta-sheet content after ethanol treatment (49.8% for Fb-F-et and 49.0% for FbMA-F-et). The elasticity modulus for the FbMA-F-et films was twofold higher than that of the Fb-F-et as measured by the uniaxial tension (130 +/- 1 MPa vs. 64 +/- 6 MPa), and 1.4 times higher (51 +/- 11 MPa vs. 36 +/- 4 MPa) as measured by atomic force microscopy. The culturing of human MG63 osteoblast-like cells on Fb-F-et, FbMA-F-et-w/oUV, and FbMA-F-et substrates revealed that the photocrosslinking-induced increment of stiffness increases the area covered by the cells, rearrangement of actin cytoskeleton, and vinculin distribution in focal contacts, altogether enhancing the osteoinductive activity of the substrate.
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