scholarly journals The Relationship between Secondary Structure and Biodegradation Behavior of Silk Fibroin Scaffolds

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Yongpei Hu ◽  
Qin Zhang ◽  
Renchuan You ◽  
Lingshuang Wang ◽  
Mingzhong Li
Keyword(s):  
Tissue Engineering ◽  
Secondary Structure ◽  
Silk Fibroin ◽  
Degradation Rate ◽  
Mechanical Performance ◽  
Tissue Growth ◽  
Random Coil ◽  
Regenerated Silk Fibroin ◽  
Sheet Structure ◽  
The Relationship

Silk fibroin has a unique and useful combination of properties, including good biocompatibility and excellent mechanical performance. These features provided early clues to the utility of regenerated silk fibroin as a scaffold/matrix for tissue engineering. The silk fibroin scaffolds used for tissue engineering should degrade at a rate that matches the tissue growth rate. The relationship between secondary structure and biodegradation behavior of silk fibroin scaffolds was investigated in this study. Scaffolds with different secondary structure were prepared by controlling the freezing temperature and by treatment with carbodiimide or ethanol. The quantitative proportions of each secondary structure were obtained by Fourier transform infrared spectroscopy (FTIR), and each sample was then degradedin vitrowith collagenase IA for 18 days. The results show that a high content ofβ-sheet structure leads to a low degradation rate. The random coil region in the silk fibroin material is degraded, whereas the crystal region remains stable and the amount ofβ-sheet structure increases during incubation. The results demonstrate that it is possible to control the degradation rate of a silk fibroin scaffold by controlling the content ofβ-sheet structure.

Chitosan/β-TCP composites scaffolds coated with silk fibroin: a bone tissue engineering approach

2021 ◽  
Vol 17 (1) ◽  
pp. 015003
Author(s):  
Lya Piaia ◽  
Simone S Silva ◽  
Joana M Gomes ◽  
Albina R Franco ◽  
Emanuel M Fernandes ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Regeneration ◽  
Bone Tissue ◽  
Silk Fibroin ◽  
Cellular Proliferation ◽  
Mechanical Performance ◽  
Tissue Growth ◽  
Polymeric Scaffolds ◽  
Bioactive Agents

Abstract Bone regeneration and natural repair are long-standing processes that can lead to uneven new tissue growth. By introducing scaffolds that can be autografts and/or allografts, tissue engineering provides new approaches to manage the major burdens involved in this process. Polymeric scaffolds allow the incorporation of bioactive agents that improve their biological and mechanical performance, making them suitable materials for bone regeneration solutions. The present work aimed to create chitosan/beta-tricalcium phosphate-based scaffolds coated with silk fibroin and evaluate their potential for bone tissue engineering. Results showed that the obtained scaffolds have porosities up to 86%, interconnectivity up to 96%, pore sizes in the range of 60–170 μm, and a stiffness ranging from 1 to 2 MPa. Furthermore, when cultured with MC3T3 cells, the scaffolds were able to form apatite crystals after 21 d; and they were able to support cell growth and proliferation up to 14 d of culture. Besides, cellular proliferation was higher on the scaffolds coated with silk. These outcomes further demonstrate that the developed structures are suitable candidates to enhance bone tissue engineering.

Effect of Solvent on the Characteristics of Electrospun Regenerated Silk Fibroin Nanofibers

2007 ◽  
Vol 342-343 ◽  
pp. 813-816 ◽  
Author(s):  
Lim Jeong ◽  
Kuen Yong Lee ◽  
Won Ho Park
Keyword(s):  
Secondary Structure ◽  
Formic Acid ◽  
Silk Fibroin ◽  
Structural Changes ◽  
Effective Means ◽  
Electrospun Nanofibers ◽  
Random Coil ◽  
Regenerated Silk Fibroin ◽  
Silk Fibroin Nanofibers ◽  
Β Sheet

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.

scholarly journals Fractionation of Regenerated Silk Fibroin and Characterization of the Fractions

Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6317
Author(s):  
Masaaki Aoki ◽  
Yu Masuda ◽  
Kota Ishikawa ◽  
Yasushi Tamada
Keyword(s):  
Mechanical Properties ◽  
Secondary Structure ◽  
Silk Fibroin ◽  
Gel Permeation Chromatography ◽  
Precipitation Process ◽  
Regenerated Silk Fibroin ◽  
Sds Page ◽  
Fractionation Method ◽  
Nonwoven Mats

The molecular weight (MW) of regenerated silk fibroin (RSF) decreases during degumming and dissolving processes. Although MW and the MW distribution generally affect polymer material processability and properties, few reports have described studies examining the influences of MW and the distribution on silk fibroin (SF) material. To prepare different MW SF fractions, the appropriate conditions for fractionation of RSF by ammonium sulfate (AS) precipitation process were investigated. The MW and the distribution of each fraction were found using gel permeation chromatography (GPC) and SDS-polyacrylamide electrophoresis (SDS-PAGE). After films of the fractionated SFs formed, the secondary structure, surface properties, and cell proliferation of films were evaluated. Nanofiber nonwoven mats and 3D porous sponges were fabricated using the fractionated SF aqueous solution. Then, their structures and mechanical properties were analyzed. The results showed AS precipitation using a dialysis membrane at low temperature to be a suitable fractionation method for RSF. Moreover, MW affects the nanofiber and sponge morphology and mechanical properties, although no influence of MW was observed on the secondary structure or crystallinity of the fabricated materials.

A comparison of centrifugally-spun and electrospun regenerated silk fibroin nanofiber structures and properties

RSC Advances ◽  
2015 ◽  
Vol 5 (119) ◽  
pp. 98553-98558 ◽  
Author(s):  
Chen Liu ◽  
Jiaqi Sun ◽  
Min Shao ◽  
Bin Yang
Keyword(s):  
Thermal Properties ◽  
Silk Fibroin ◽  
Secondary Structures ◽  
Random Coil ◽  
Structures And Properties ◽  
Regenerated Silk Fibroin ◽  
Centrifugal Spinning ◽  
Β Sheet

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.

scholarly journals Effect of Pore Size on the Biodegradation Rate of Silk Fibroin Scaffolds

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Zuwei Luo ◽  
Qin Zhang ◽  
Meijing Shi ◽  
Yang Zhang ◽  
Wei Tao ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Weight Loss ◽  
Pore Size ◽  
Silk Fibroin ◽  
Degradation Rate ◽  
Structural Integrity ◽  
Pore Density ◽  
Tissue Engineering Scaffolds ◽  
Silk Scaffolds

Controlling the degradation rate of silk fibroin-based biomaterial is an important capability for the fabrication of silk-based tissue engineering scaffolds. In this study, scaffolds with different pore sizes were prepared by controlling the freezing temperature and the silk fibroin concentration.In vitrodegradation results showed that the internal pore walls of the scaffolds with a larger pore size collapsed upon exposure to collagenase IA for times ranging from 6 to 12 days, and the silk scaffolds exhibited a faster rate of weight loss. The morphological and structural features of the silk scaffolds with a smaller pore size maintained structural integrity after incubation in the protease solution for 18 days, and the rate of weight loss was relatively slow. Scaffolds with a smaller pore size or a higher pore density degraded more slowly than scaffolds with a larger pore size or lower pore density. These results demonstrate that the pore size of silk biomaterials is crucial in controlling the degradation rate of tissue engineering scaffolds.

scholarly journals Effect of pH on the Conformational Transition of Silk Fibroin in Aqueous Solution Monitored by Thioflavin-T Fluorescence

2021 ◽  
Author(s):  
Ben Jia ◽  
Lan Jia ◽  
Jingxin Zhu
Keyword(s):  
Aqueous Solution ◽  
Secondary Structure ◽  
Silk Fibroin ◽  
Conformational Transition ◽  
Thioflavin T ◽  
Random Coil ◽  
Fluorescence Dye ◽  
Assembly Behavior ◽  
Β Sheet

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.

Preparation and Characterization of Silk Fibroin-Based Hybrid Vascular Tissue Engineering Film

2020 ◽  
Vol 996 ◽  
pp. 64-69
Author(s):  
Ping Deng Ming ◽  
Chuan Jun Xia ◽  
Ya Song Hu ◽  
Cong Cong Zhan ◽  
An Duo Zhou ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Silk Fibroin ◽  
Hybrid Film ◽  
Vascular Tissue ◽  
Water Drop ◽  
Alpha Helix ◽  
Biological Properties ◽  
Random Coil ◽  
Polymeric Composite Material ◽  
Cardiovascular Tissue

Patients suffering from cardiovascular disease lack suitable stent. In this study, a new polymeric composite material was prepared by incorporating various concentrations of gamma-glycidoxypropyltrimethoxysilane (GPTMS) into silk fibroin (SF), aiming at achieving a novel composite film with superior mechanical and biological properties, in order to match the requirement of cardiovascular tissue engineering stents. Fourier transform infrared spectroscopy (FTIR) analysis showed that GPTM could promote SF to transform from the original alpha helix and random coil/extension chain conformation to the beta-folded conformation. Tensile experiment indicated tensile strength and breaking elongation of SF/GPTMS hybrid film reach the maximum with 20% GPTMS content. Within a certain range, the water drop contact angle of SF/GPTMS hybrid film is positively correlated with the content of GPTMS. Endothelial cells (ECs) are best grown on hybrid SF/GPTMS hybrid film with 20% GPTMS content.

Silk Fibroin: A Promising Biomaterial

2011 ◽  
Vol 409 ◽  
pp. 99-104 ◽  
Author(s):  
Mariana Agostini de Moraes ◽  
Mariana Ferreira Silva ◽  
Raquel Farias Weska ◽  
Marisa Masumi Beppu
Keyword(s):  
Tissue Engineering ◽  
Controlled Release ◽  
Secondary Structure ◽  
Bombyx Mori ◽  
Structural Properties ◽  
Silk Fibroin ◽  
Protein Secondary Structure ◽  
Processing Conditions ◽  
Protein Fiber

Silk fibroin (SF) is a protein fiber spun by Bombyx mori silkworm. SF fibers are about 10-25 μm wide in diameter and a single cocoon may provide over 1000 m of SF fibers. SF can present several conformations regarding protein secondary structure which ultimately define the structural properties of SF-based materials. For this reason, a rigorous control on its processing conditions shall be performed. It is known that SF has excellent properties to be used in biomaterials field, controlled release and scaffolds for tissue engineering. In addition, SF can be processed in several forms, such as films, fibers, hydrogels or microparticles. This work seeks to provide an overview on SF processing conditions, regarding the preparation of SF membranes (dense and porous), hydrogels and biocomposites, focusing on biomaterials application.

EFFECT OF STORAGE TIME AND CONCENTRATION ON STRUCTURE OF REGENERATED SILK FIBROIN SOLUTION

2006 ◽  
Vol 20 (25n27) ◽  
pp. 3878-3883 ◽  
Author(s):  
FANG XIE ◽  
HUILI SHAO ◽  
XUECHAO HU
Keyword(s):  
Aqueous Solution ◽  
Silk Fibroin ◽  
Storage Time ◽  
Conformational Transition ◽  
Solution Concentration ◽  
Cd Spectroscopy ◽  
Random Coil ◽  
Conformational Transformation ◽  
Regenerated Silk Fibroin ◽  
Α Helix

Concentrated regenerated silk fibroin (RSF) aqueous solutions with concentration close to that of the native silk fibroin (15.5%, 25.5% and 31%) were prepared. The effect of storage time and concentration on the conformational transition of the concentrated RSF aqueous solution was studied by Raman spectroscopy and circular dichroism (CD) spectroscopy. At the same time, the conformational change of RSF aqueous solution in flowing state was also investigated. It was found that the conformation of silk fibroin was changed gradually from random coil/α-helix to β-sheet structure during the storage. And the conformational transformation was accelerated with the increasing of the RSF aqueous solution concentration. When the solution was in flowing state, the conformational transformation was also accelerated.

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