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David L Kaplan - One of the best experts on this subject based on the ideXlab platform.
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Photo-Crosslinked Silk Fibroin for 3D Printing.
Polymers, 2020Co-Authors: Jugal Kishore Sahoo, Peggy Cebe, David L KaplanAbstract:Silk Fibroin in material formats provides robust mechanical properties, and thus is a promising protein for 3D printing inks for a range of applications, including tissue engineering, bioelectronics, and bio-optics. Among the various crosslinking mechanisms, photo-crosslinking is particularly useful for 3D printing with Silk Fibroin inks due to the rapid kinetics, tunable crosslinking dynamics, light-assisted shape control, and the option to use visible light as a biocompatible processing condition. Multiple photo-crosslinking approaches have been applied to native or chemically modified Silk Fibroin, including photo-oxidation and free radical methacrylate polymerization. The molecular characteristics of Silk Fibroin, i.e., conformational polymorphism, provide a unique method for crosslinking and microfabrication via light. The molecular design features of Silk Fibroin inks and the exploitation of photo-crosslinking mechanisms suggest the exciting potential for meeting many biomedical needs in the future.
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Silk Fibroin as edible coating for perishable food preservation
Scientific Reports, 2016Co-Authors: Benedetto Marelli, David L Kaplan, Mark A Brenckle, Fiorenzo G. OmenettoAbstract:The regeneration of structural biopolymers into micelles or nanoparticles suspended in water has enabled the design of new materials with unique and compelling properties that can serve at the interface between the biotic and the abiotic worlds. In this study, we leveraged Silk Fibroin quintessential properties (i.e. polymorphism, conformability and hydrophobicity) to design a water-based protein suspension that self-assembles on the surface of food upon dip coating. The water-based post-processing control of the protein polymorphism enables the modulation of the diffusion of gases through the Silk Fibroin thin membranes (e.g. O2 and CO2 diffusion, water vapour permeability), which is a key parameter to manage food freshness. In particular, an increased beta-sheet content corresponds to a reduction in oxygen diffusion through Silk Fibroin thin films. By using the dip coating of strawberries and bananas as proof of principle, we have shown that the formation of micrometre-thin Silk Fibroin membranes around the fruits helps the management of postharvest physiology of the fruits. Thus, Silk Fibroin coatings enhance fruits' shelf life at room conditions by reducing cell respiration rate and water evaporation. The water-based processing and edible nature of Silk Fibroin makes this approach a promising alternative for food preservation with a naturally derived material.
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The effect of sterilization on Silk Fibroin biomaterial properties
Macromolecular bioscience, 2015Co-Authors: Jelena Rnjak-kovacina, David L Kaplan, Teresa M. Desrochers, Kelly A. Burke, David L KaplanAbstract:The effects of common sterilization techniques on the physical and biological properties of lyophilized Silk Fibroin sponges are described. Sterile Silk Fibroin sponges were cast using a pre-sterilized Silk Fibroin solution under aseptic conditions or post-sterilized via autoclaving, γ radiation, dry heat, exposure to ethylene oxide, or hydrogen peroxide gas plasma. Low average molecular weight and low concentration Silk Fibroin solutions could be sterilized via autoclaving or filtration without significant loses of protein. However, autoclaving reduced the molecular weight distribution of the Silk Fibroin protein solution, and Silk Fibroin sponges cast from autoclaved Silk Fibroin were significantly stiffer compared to sponges cast from unsterilized or filtered Silk Fibroin. When Silk Fibroin sponges were sterilized post-casting, autoclaving increased scaffold stiffness, while decreasing scaffold degradation rate in vitro. In contrast, γ irradiation accelerated scaffold degradation rate. Exposure to ethylene oxide significantly decreased cell proliferation rate on Silk Fibroin sponges, which was rescued by leaching ethylene oxide into PBS prior to cell seeding.
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Biocompatible Silk Fibroin Optical Fibers
Advanced Photonics 2015, 2015Co-Authors: Matthew B. Applegate, Alexander N. Mitropoulos, Giovanni Perotto, David L Kaplan, Fiorenzo G. OmenettoAbstract:Biocompatible waveguides were created by encapsulating a Silk Fibroin film (n=1.54) inside a Silk Fibroin hydrogel (n=1.34). We found these structures capable of guiding light in tissue.
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Flexibility regeneration of Silk Fibroin in vitro.
Biomacromolecules, 2012Co-Authors: Cencen Zhang, David L Kaplan, Dawei Song, He Sun ZhuAbstract:Although natural Silk fibers have excellent strength and flexibility, the regenerated Silk materials generally become brittle in the dry state. How to reconstruct the flexibility for Silk Fibroin has bewildered scientists for many years. In the present study, the flexible regenerated Silk Fibroin films were achieved by simulating the natural forming and spinning process. Silk Fibroin films composed of Silk I structure were first prepared by slow drying process. Then, the Silk Fibroin films were stretched in the wet state, following the structural transition from Silk I to Silk II. The difference between the flexible film and different brittle regenerated films was investigated to reveal the critical factors in regulating the flexibility of regenerated Silk materials. Compared with the methanol-treated Silk films, although having similar Silk II structure and water content, the flexible Silk films contained more bound water rather than free water, implying the great influence of bound water on the flexibility. Then, further studies revealed that the distribution of bound water was also a critical factor in improving Silk flexibility in the dry state, which could be regulated by the nanoassembly of Silk Fibroin. Importantly, the results further elucidate the relation between mechanical properties and Silk Fibroin structures, pointing to a new mode of generating new types of Silk materials with enhanced mechanical properties in the dry state, which would facilitate the fabrication and application of regenerated Silk Fibroin materials in different fields.
Jirut Meesane - One of the best experts on this subject based on the ideXlab platform.
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biphasic scaffolds of Silk Fibroin film affixed to Silk Fibroin chitosan sponge based on surgical design for cartilage defect in osteoarthritis
Materials & Design, 2018Co-Authors: Khanitta Panjapheree, Suttatip Kamonmattayakul, Jirut MeesaneAbstract:Abstract Osteoarthritis is inflammation that can occur at any joint, and is caused by cartilage degeneration. For severe cases, patients need surgery by substitution with performance tissue engineering scaffolds. Biphasic scaffolds of Silk Fibroin film affixed to a Silk Fibroin/chitosan sponge were constructed for osteoarthritis surgery. Silk Fibroin film was fabricated before affixation to the sponge of Silk Fibroin/chitosan at different ratios of Silk Fibroin to chitosan: 100:0 (SF), 70:30 (SF70), 50:50 (SF50), 30:70 (SF30), and 0:100 (CS). The morphologies of the scaffolds were observed by scanning electron microscopy. Physical functionality as well as stability was evaluated from mechanical properties, and the percentage of swelling, and degradation. Biological functionality was evaluated using a rat mesenchymal stem cell (RMSCs) culture. Cell proliferation was analyzed and the histological structure was observed. SF30 showed suitable morphology, physical stability, and biological functionality to promote RMSC regulation into chondrocytes. This indicated that SF30 shows promise for cartilage regeneration in osteoarthritis surgery.
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Biphasic scaffolds of Silk Fibroin film affixed to Silk Fibroin/chitosan sponge based on surgical design for cartilage defect in osteoarthritis
Materials & Design, 2018Co-Authors: Khanitta Panjapheree, Suttatip Kamonmattayakul, Jirut MeesaneAbstract:Abstract Osteoarthritis is inflammation that can occur at any joint, and is caused by cartilage degeneration. For severe cases, patients need surgery by substitution with performance tissue engineering scaffolds. Biphasic scaffolds of Silk Fibroin film affixed to a Silk Fibroin/chitosan sponge were constructed for osteoarthritis surgery. Silk Fibroin film was fabricated before affixation to the sponge of Silk Fibroin/chitosan at different ratios of Silk Fibroin to chitosan: 100:0 (SF), 70:30 (SF70), 50:50 (SF50), 30:70 (SF30), and 0:100 (CS). The morphologies of the scaffolds were observed by scanning electron microscopy. Physical functionality as well as stability was evaluated from mechanical properties, and the percentage of swelling, and degradation. Biological functionality was evaluated using a rat mesenchymal stem cell (RMSCs) culture. Cell proliferation was analyzed and the histological structure was observed. SF30 showed suitable morphology, physical stability, and biological functionality to promote RMSC regulation into chondrocytes. This indicated that SF30 shows promise for cartilage regeneration in osteoarthritis surgery.
Baoqi Zuo - One of the best experts on this subject based on the ideXlab platform.
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Application of Silk Fibroin scaffold in bone tissue engineering
Zhongguo xiu fu chong jian wai ke za zhi = Zhongguo xiufu chongjian waike zazhi = Chinese journal of reparative and reconstructive surgery, 2014Co-Authors: Baoqi Zuo, Hongchen LiuAbstract:OBJECTIVE To review the application of Silk Fibroin scaffold in bone tissue engineering. METHODS The related literature about the application of Silk Fibroin scaffold in bone tissue engineering was reviewed, analyzed, and summarized. RESULTS Silk Fibroin can be manufactured into many types, such as hydrogel, film, nano-fiber, and three-dimensional scaffold, which have superior biocompatibility, slow biodegradability, nontoxic degradation products, and excellent mechanical strength. Meanwhile these Silk Fibroin biomaterials can be chemically modified and can be used to carry stem cells, growth factors, and compound inorganic matter. CONCLUSION Silk Fibroin scaffolds can be widely used in bone tissue engineering. But it still needs further study to prepare the scaffold in accordance with the requirement of tissue engineering.
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Silk I structure formation through Silk Fibroin self‐assembly
Journal of Applied Polymer Science, 2012Co-Authors: Jinfa Ming, Baoqi ZuoAbstract:Regenerated Silk Fibroin films are normally produced by increasing the Silk II structure (β-sheet content). In the present study, Silk Fibroin films were prepared by controlling the environmental temperature and humidity, resulting in the formation of Silk films with a predominant Silk I structure instead of Silk II structure. Wide angle X-ray diffraction indicated that when the relative humidity was 55%, the Silk films prepared were mainly composed of Silk I structure, whereas Silk films formed on other relative humidity had a higher Silk II structure. Fourier transform infrared analysis (FTIR) results also conformed that the secondary structure of Silk Fibroin can be controlled by changing the humidity of the films formed process. Thermal analysis results revealed Silk I structure was a stable crystal, and the degradation peak increased to 320°C, indicating a greater thermal stability of these films formed under the 55% relative humidity conditions. Atomic force microscopy (AFM) results depicted Silk Fibroin in the fresh solution had many nanospheres existing with 20–50 nm diameters and mainly maintained a random coil structure without specific nanostructures. At the same time, it also illustrated the self-assembly process of Silk Fibroin in the aqueous solution without any human intervention. In addition, this present study also provided additional support for self-assembly mechanism of Silk Fibroin films formation. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
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A novel electrospun Silk Fibroin/hydroxyapatite hybrid nanofibers
Materials Chemistry and Physics, 2012Co-Authors: Jinfa Ming, Baoqi ZuoAbstract:Abstract A novel electrospinning of Silk Fibroin/hydroxyapatite hybrid nanofibers with different composition ratios was performed with methanoic acid as a spinning solvent. The Silk Fibroin/hydroxyapatite hybrids containing up to 30% hydroxyapatite nanoparticles could be electrospun into the continuous fibrous structure. The electrospun Silk Fibroin/hydroxyapatite hybrid nanofibers showed bigger diameter and wider diameter distribution than pure Silk Fibroin nanofibers, and the average diameter gradually increased from 95 to 582 nm. At the same time, the secondary structure of Silk Fibroin/hydroxyapatite nanofibers was characterized by X-ray diffraction, Fourier transform infrared analysis, and DSC measurement. Comparing with the pure Silk Fibroin nanofibers, the crystal structure of Silk Fibroin was mainly amorphous structure in the hybrid nanofibers. X-ray diffraction results demonstrated the hydroxyapatite crystalline nature remained as evidenced from the diffraction planes (002), (211), (300), and (202) of the hydroxyapatite crystallites, which was also confirmed by Fourier transform infrared analysis. The thermal behavior of hybrid nanofibers exhibited the endothermic peak of moisture evaporation ranging from 86 to 113 °C, and the degradation peak at 286 °C appeared. The SF/HAp nanofibers mats containing 30% HAp nanoparticles showed higher breaking tenacity and extension at break for 1.1688 ± 0.0398 MPa and 6.55 ± 1.95%, respectively. Therefore, the electrospun Silk Fibroin/hydroxyapatite hybrid nanofibers should be provided potentially useful options for the fabrication of biomaterial scaffolds for bone tissue engineering.
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Silk Fibroin electrogelation mechanisms
Acta biomaterialia, 2011Co-Authors: Yongli Huang, He Sun Zhu, Baoqi Zuo, Jiannan Wang, David L KaplanAbstract:A Silk Fibroin gel system (e-gel), formed with weak electric fields, has potential utility in medical materials and devices. The mechanism of Silk e-gel formation was studied to gain additional insight into the process and control of the material properties. Silk Fibroin nanoparticles with sizes of tens of nanometers, composed of metastable conformations, were involved in e-gel formation. Under electric fields the nanoparticles rapidly assembled into larger nano- or microspheres with size range from tens of nanometers to several microns. Repulsive forces from the negative surface charge of the acidic groups on the protein were screened by the local decrease in solution pH in the vicinity of the positive electrode. By controlling the formation and content of Silk Fibroin nanoparticles e-gels could be formed even from low concentration Silk Fibroin solutions (1%). When e-gel formation was reversed to the solution state the aggregated nano- and microspheres dispersed into solution, a significant observation related to future applications for this process, such as drug delivery.
A. Płanecka - One of the best experts on this subject based on the ideXlab platform.
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Surface properties of thin films based on the mixtures of chitosan and Silk Fibroin
Journal of Molecular Liquids, 2013Co-Authors: Alina Sionkowska, A. PłaneckaAbstract:Abstract Thin films by solvent evaporation from mixture of chitosan and Silk Fibroin were prepared. The interactions between components in the blend were studied by FTIR spectroscopy. The surface properties of chitosan/Silk Fibroin blended films were investigated using the technique of Atomic Force Microscopy (AFM) and by means of contact angle measurements allowing the calculation of surface free energy. Measurements of the contact angle for diiodomethane (D), and glycerol (G) on the surface of chitosan films and chitosan/Silk Fibroin films were made and surface free energy was calculated. The surface of thin films based on the blends of chitosan and Silk Fibroin was modified by UV-irradiation with the wavelength λ = 254 nm. It was found that chitosan/Silk Fibroin blend surface is enriched in high surface energy component i.e. Silk Fibroin. The contact angle and the surface free energy were altered by UV-irradiation for both chitosan and chitosan/Silk Fibroin films. The surface roughness of chitosan, Silk Fibroin and chitosan/Silk Fibroin blended films was altered by UV-irradiation. UV-irradiation caused the decrease of surface roughness of chitosan films, Silk Fibroin films and films made of the mixture of chitosan and Silk Fibroin.
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The influence of UV radiation on Silk Fibroin
Polymer Degradation and Stability, 2011Co-Authors: Alina Sionkowska, A. PłaneckaAbstract:Abstract An investigation into the influence of UV-irradiation on regenerated Silk Fibroin dissolved in water was carried out using UV–Vis and fluorescence spectroscopy. It was found that the absorption of regenerated Silk Fibroin in solution increased during UV-irradiation of the sample, most notably between 250 and 400 nm. Moreover, after UV-irradiation a wide peak emerged between 290 and 340 nm with maximum at about 305 nm. The new peak suggests that new photoproducts are formed during UV-irradiation of regenerated Silk Fibroin. The fluorescence of regenerated Silk Fibroin was observed at 305 nm, at 480 nm and at 601 nm after excitation at 275 nm. UV-irradiation caused fluorescence fading at 305 nm and at 601 nm. The increase of fluorescence was observed at 480 nm, probably due to formation of new photoproducts. After excitation at 305 nm the fluorescence of regenerated Silk Fibroin was observed at 340 nm and at 400 nm. UV-irradiation caused fluorescence fading at 340 nm. FTIR spectroscopy showed that primary structure of regenerated Silk Fibroin was not significantly affected by UV radiation. SDS-PAGE chromatography showed alterations of molecular weight of Silk after UV exposure.
Xin Chen - One of the best experts on this subject based on the ideXlab platform.
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Comparison of Native and Regenerated Antheraea Pernyi Silk Fibroin
Materials Science, 2021Co-Authors: Yu Duan, Xin Chen, Zhengzhong ShaoAbstract:The regenerated Antheraea pernyi Silk Fibroin (RASF) was harvested by dissolving the Silk fibers in a calcium nitrate solution. XRD result demonstrated that both native and regenerated Antheraea pernyi Silk Fibroin involved the α-helix conformation, and DTG curves showed that their thermal decompositions were quite similar and proceeded three steps. However, rheological measurements figured out that the molecule weight of RASF decreased from 246 kDa to 199 kDa, comparing with native Antheraea pernyi Silk Fibroin. Also, the tensile properties of the RASF film, which were the same to those of regenerated Bombyx mori Silk Fibroin film, were observed.
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Paclitaxel-loaded Silk Fibroin nanospheres.
Journal of Biomedical Materials Research Part A, 2011Co-Authors: Mengjie Chen, Zhengzhong Shao, Xin ChenAbstract:Silk Fibroin is a very promising biomedical material because of its renewability, nontoxicity, biocompatibility, and biodegradability. On the basis of a simple and mild method for the preparation of Silk Fibroin nanospheres with controllable size, the authors developed earlier, anti-cancer drug paclitaxel (PTX)-loaded Silk Fibroin nanospheres ranging from 270 to 520 nm were produced accordingly. The drug loading, encapsulation efficiency, and released property of PTX-loaded Silk Fibroin nanospheres are depended on the Silk Fibroin concentration and initial PTX-loading capacity. The maximum drug loading is about 6.9% and the release time of such a kind of nanospheres is over 9 days. The release time of PTX-loaded Silk Fibroin nanospheres can be as long as 2 weeks when the drug loading is about 3.0%. All these results imply that such a kind of biomacromolecule-based anti-cancer drug nanocarrier has a great potential for chemotherapy in clinical applications. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.
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Paclitaxel-loaded Silk Fibroin nanospheres †
Journal of biomedical materials research. Part A, 2011Co-Authors: Mengjie Chen, Zhengzhong Shao, Xin ChenAbstract:Silk Fibroin is a very promising biomedical material because of its renewability, nontoxicity, biocompatibility, and biodegradability. On the basis of a simple and mild method for the preparation of Silk Fibroin nanospheres with controllable size, the authors developed earlier, anti-cancer drug paclitaxel (PTX)-loaded Silk Fibroin nanospheres ranging from 270 to 520 nm were produced accordingly. The drug loading, encapsulation efficiency, and released property of PTX-loaded Silk Fibroin nanospheres are depended on the Silk Fibroin concentration and initial PTX-loading capacity. The maximum drug loading is about 6.9% and the release time of such a kind of nanospheres is over 9 days. The release time of PTX-loaded Silk Fibroin nanospheres can be as long as 2 weeks when the drug loading is about 3.0%. All these results imply that such a kind of biomacromolecule-based anti-cancer drug nanocarrier has a great potential for chemotherapy in clinical applications. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.
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The preparation of regenerated Silk Fibroin microspheres
Soft matter, 2007Co-Authors: Zhengbing Cao, Xin Chen, Jinrong Yao, Lei Huang, Zhengzhong ShaoAbstract:The objective of the present study is to investigate the possibility of preparing pure protein microspheres from regenerated Silk Fibroin (RSF). It is found that RSF microspheres, with predictable and controllable sizes ranging from 0.2 to 1.5 µm, can be prepared via mild self-assembling of Silk Fibroin molecular chains. The merits of this novel method include a rather simple production apparatus and no potentially toxic agents, such as surfactants, initiators, cross-linking agents, etc. The results show that the particle size and size distribution of RSF microspheres are greatly affected by the amount of ethanol additive, the freezing temperature and the concentration of Silk Fibroin. Finally, the mechanism of RSF microspheres formation is also discussed based on our experimental results.
