In this paper, the main goal is to prepare silk fibroin nano-fiber, which is used for regenerated tissue applications. Silk scaffold nano-fibers made by electro-spinning technology can be used in regenerated tissue ap...In this paper, the main goal is to prepare silk fibroin nano-fiber, which is used for regenerated tissue applications. Silk scaffold nano-fibers made by electro-spinning technology can be used in regenerated tissue applications. The purpose of the research is to prepare a silk-fibroin nano-fiber solution for potential applications in tissue engineering. Using a degumming process, pure silk fibroin protein is extracted from silk cocoons. The protein solution for fibroin is purified, and the protein content is determined. The precise chemical composition, exact temperature, time, voltage, distance, ratio, and humidity all have a huge impact on degumming, solubility, and electro-spinning nano-fibers. The SEM investigates the morphology of silk fibroin nano-fibres at different magnifications. It also reveals the surface condition, fiber orientation, and fiber thickness of the silk fibroin nano-fiber. The results show that regenerated silk fibroin and nano-fiber can be used in silk fibroin scaffolds for various tissue engineering applications.展开更多
Regenerative medicine progress is based on the development of cell and tissue bioengineering. One of the aims of tissue engineering is the development of scaffolds, which should substitute the functions of the replace...Regenerative medicine progress is based on the development of cell and tissue bioengineering. One of the aims of tissue engineering is the development of scaffolds, which should substitute the functions of the replaced organ after their implantation into the body. The tissue engineering material must meet a range of requirements, including biocompatibility, mechanical strength, and elasticity. Furthermore, the materials have to be attractive for cell growth: stimulate cell adhesion, migration, proliferation and differentiation. One of the natural biomaterials is silk and its component (silk fibroin). An increasing number of scientists in the world are studying silk and silk fibroin. The purpose of this review article is to provide information about the properties of natural silk (silk fibroin), as well as its manufacture and clinical application of each configuration of silk fibroin in medicine. Materials and research methods. Actual publications of foreign authors on resources PubMed, Medline, E-library have been analyzed. The selection criteria were materials containing information about the structure and components of silk, methods of its production in nature. This article placed strong emphasis on silk fibroin, the ways of artificial modification of it for use in various sphere of medicine.展开更多
Many studies have shown that bio-scaffolds have important value for promoting axonal regeneration of injured spinal cord.Indeed,cell transplantation and bio-scaffold implantation are considered to be effective methods...Many studies have shown that bio-scaffolds have important value for promoting axonal regeneration of injured spinal cord.Indeed,cell transplantation and bio-scaffold implantation are considered to be effective methods for neural regeneration.This study was designed to fabricate a type of three-dimensional collagen/silk fibroin scaffold (3D-CF) with cavities that simulate the anatomy of normal spinal cord.This scaffold allows cell growth in vitro and in vivo.To observe the effects of combined transplantation of neural stem cells (NSCs) and 3D-CF on the repair of spinal cord injury.Forty Sprague-Dawley rats were divided into four groups: sham (only laminectomy was performed),spinal cord injury (transection injury of T10 spinal cord without any transplantation),3D-CF (3D scaffold was transplanted into the local injured cavity),and 3D-CF + NSCs (3D scaffold co-cultured with NSCs was transplanted into the local injured cavity.Neuroelectrophysiology,imaging,hematoxylin-eosin staining,argentaffin staining,immunofluorescence staining,and western blot assay were performed.Apart from the sham group,neurological scores were significantly higher in the 3D-CF + NSCs group compared with other groups.Moreover,latency of the 3D-CF + NSCs group was significantly reduced,while the amplitude was significantly increased in motor evoked potential tests.The results of magnetic resonance imaging and diffusion tensor imaging showed that both spinal cord continuity and the filling of injury cavity were the best in the 3D-CF + NSCs group.Moreover,regenerative axons were abundant and glial scarring was reduced in the 3D-CF + NSCs group compared with other groups.These results confirm that implantation of 3D-CF combined with NSCs can promote the repair of injured spinal cord.This study was approved by the Institutional Animal Care and Use Committee of People’s Armed Police Force Medical Center in 2017 (approval No.2017-0007.2).展开更多
Treatment and functional reconstruction after central nervous system injury is a major medical and social challenge. An increasing number of researchers are attempting to use neural stem cells combined with artificial...Treatment and functional reconstruction after central nervous system injury is a major medical and social challenge. An increasing number of researchers are attempting to use neural stem cells combined with artificial scaffold materials, such as fibroin, for nerve repair. However, such approaches are challenged by ethical and practical issues. Amniotic tissue, a clinical waste product, is abundant, and amniotic epithe- lial cells are pluripotent, have low immunogenicity, and are not the subject of ethical debate. We hypothesized that amniotic epithelial cells combined with silk fibroin scaffolds would be conducive to the repair of spinal cord injury. To test this, we isolated and cultured amniotic epithelial cells, and constructed complexes of these cells and silk fibroin scaffolds. Implantation of the cell-scaffold complex into a rat model of spinal cord injury resulted in a smaller glial scar in the damaged cord tissue than in model rats that received a blank scaffold, or amniotic epithelial cells alone. In addition to a milder local immunological reaction, the rats showed less inflammatory cell infiltration at the trans- plant site, milder host-versus-graft reaction, and a marked improvement in motor function. These findings confirm that the transplantation of amniotic epithelial ceils combined with silk fibroin scaffold can promote the repair of spinal cord injury. Silk fibroin scaffold can provide a good nerve regeneration microenvironment for amniotic epithelial cells.展开更多
Three dimensional(3D) bioprinting, which involves depositing bioinks(mixed biomaterials) layer by layer to form computer-aided designs, is an ideal method for fabricating complex 3D biological structures. However,...Three dimensional(3D) bioprinting, which involves depositing bioinks(mixed biomaterials) layer by layer to form computer-aided designs, is an ideal method for fabricating complex 3D biological structures. However, it remains challenging to prepare biomaterials with micro-nanostructures that accurately mimic the nanostructural features of natural tissues. A novel nanotechnological tool, electrospinning, permits the processing and modification of proper nanoscale biomaterials to enhance neural cell adhesion, migration, proliferation, differentiation, and subsequent nerve regeneration. The composite scaffold was prepared by combining 3D bioprinting with subsequent electrochemical deposition of polypyrrole and electrospinning of silk fibroin to form a composite polypyrrole/silk fibroin scaffold. Fourier transform infrared spectroscopy was used to analyze scaffold composition. The surface morphology of the scaffold was observed by light microscopy and scanning electron microscopy. A digital multimeter was used to measure the resistivity of prepared scaffolds. Light microscopy was applied to observe the surface morphology of scaffolds immersed in water or Dulbecco's Modified Eagle's Medium at 37℃ for 30 days to assess stability. Results showed characteristic peaks of polypyrrole and silk fibroin in the synthesized conductive polypyrrole/silk fibroin scaffold, as well as the structure of the electrospun nanofiber layer on the surface. The electrical conductivity was 1 × 10^-5–1 × 10^-3 S/cm, while stability was 66.67%. A 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay was employed to measure scaffold cytotoxicity in vitro. Fluorescence microscopy was used to observe Ed U-labeled Schwann cells to quantify cell proliferation. Immunohistochemistry was utilized to detect S100β immunoreactivity, while scanning electron microscopy was applied to observe the morphology of adherent Schwann cells. Results demonstrated that the polypyrrole/silk fibroin scaffold was not cytotoxic and did not affect Schwann cell proliferation. Moreover, filopodia formed on the scaffold and Schwann cells were regularly arranged. Our findings verified that the composite polypyrrole/silk fibroin scaffold has good biocompatibility and may be a suitable material for neural tissue engineering.展开更多
Spinal cord injury repair is one of the major challenges in medicine,as it can lead to permanent loss of function of central nervous system and damage to other function of the body.Stem cell transplantation together w...Spinal cord injury repair is one of the major challenges in medicine,as it can lead to permanent loss of function of central nervous system and damage to other function of the body.Stem cell transplantation together with tissue engineering is increasingly becoming a potential choice of treatment.However,direct transplantation of stem cells without scaffolds has yielded poor clinical outcome.Here we show a strategy of using mouse embryonic stem cells(ESCs)cultured within a silk fibroin(SF)based,three-dimensional scaffold with oriented channels by a directional temperature field freezing technique and lysophilization.We find that the ESCs maintained proliferation and migrated in the scaffolds and the cells migrated fastest along the SF channels.SF scaffolds contributed to ESC differentiation into neural and glial cell like cells and expressions of the neural and glial cell markers MAP2 and GFAP were greatly elevated when retinoic acid was used as an inducing factor.Our results suggest that this approach may offer some hope in the future for spinal cord injury repair using SF scaffolds and ESCs.展开更多
Besides excellent biodegradability and biocompatibility,a useful tissue engineering scaffold should provide favorable surface properties,outstanding mechanical strength and controlled drug release property. In this pa...Besides excellent biodegradability and biocompatibility,a useful tissue engineering scaffold should provide favorable surface properties,outstanding mechanical strength and controlled drug release property. In this paper,a mild process to prepare porous tussah silk fibroin( TSF) scaffolds from aqueous solution was described. The n-butanol was used to control the self-assembly of tussah silk. The scaffolds with different TSF concentrations and the same volume showed differences in pore size and distribution. The maximum porosity of the poprepared porous scaffolds was 80% in this paper. And the pore size of the prepared porous scaffolds with different concentrations was between 10μm and 230 μm. X-ray diffraction( XRD) analysis revealed that amorphous TSF was crystallized to β-sheet secondary structure upon gelatin. The TSF scaffolds for controlled drug release was studied and the result showed that the time of drug release was significantly longer. The produced TSF scaffolds with sustained drug release have potential application in tissue engineering.展开更多
Vitamin E( VE) is an ideal antioxidant and a stabilizing agent in biological membranes. In this study,silk fibroin( SF) /hydroxybutyl chitosan( HBC) nanofibrous scaffolds are loaded with VE tocopherol polyethylene gly...Vitamin E( VE) is an ideal antioxidant and a stabilizing agent in biological membranes. In this study,silk fibroin( SF) /hydroxybutyl chitosan( HBC) nanofibrous scaffolds are loaded with VE tocopherol polyethylene glycol 1000 succinate( VE TPGS) via electrospinning. SEM images show that the average nanofibrous diameter has no significant difference when the content of VE TPGS increases to 4. 0%( SF / HBC). However,the average nanofibrous diameter decreases largely to 200 nm when the VE TPGS content reaches 6. 0%. Furthermore,VE TPGS presents a sustained release behavior from the nanofibrous scaffolds. Cell viability studies of mouse skin fibroblasts( L929) demonstrate that VE TPGS loaded SF / HBC nanofibrous scaffolds present good cellular compatibility.Moreover,the incorporation of VE TPGS could strengthen the ability of SF / HBC nanofibrous scaffolds on protecting the cells against oxidation stress using the Tertbutyl hydroperoxide( t-BHP)-induced oxidative injury model. Therefore,VE TPGS-loaded SF /HBC nanofibrous scaffolds might be potential candidates for personal skin care,wound dressing and skin tissue engineering scaffolds.展开更多
In order to investigate the effect ofArg-Gly-Asp (RGD) peptide-modified silk biomaterial on the adhesion and proliferation of bone marrow-derived mesenchymal stem cells (MSCs), MSCs of third generation were seeded...In order to investigate the effect ofArg-Gly-Asp (RGD) peptide-modified silk biomaterial on the adhesion and proliferation of bone marrow-derived mesenchymal stem cells (MSCs), MSCs of third generation were seeded onto the surface of RGD-decorated silk (silk-RGD group), silk alone (silk group) or tissue culture plate (TCP group). After incubation for 4 or 12 h, MSCs were examined quantitatively by using precipitation method for cell attachment. The cell proliferation, which was defined as cell density, was compared among the three groups after culture for 1, 2, 3, and 4 days. Cell skeleton, which was labeled fluorescently, was observed under laser confocal microscope after 24 h of culture. The results showed that cell adhesion rate in silk-RGD group was higher than in silk group (P〈0.05), but similar to that in TCP group after incubation for 4 or 12 h (P〉0.05). There were no sig- nificant differences in the cell proliferation among the three groups at different time points (P〉0.05 for all). Laser confocal microscopy revealed that in silk-RGD group, MSCs, strongly fluorescently stained, spread fully, with stress fibers clearly seen, while in silk group, actin filaments were sparsely aligned and less stress fibers were found. It was concluded that RGD peptide could improve the ad- hesion of MSCs to the silk scaffold, but had no impact on the proliferation of the cells.展开更多
Establishing an appropriate degradation rate is critical for tissue engineering scaffolds. In this study, the degradation rate of silk fibroin three-dimensional scaffolds was regulated by changing the molecular weight...Establishing an appropriate degradation rate is critical for tissue engineering scaffolds. In this study, the degradation rate of silk fibroin three-dimensional scaffolds was regulated by changing the molecular weight (MW) of the silk fibroin. The solubility of silk fibroin depends primarily on the ionic ability of the slovent to dissolve silk fibroin, therefore, we regulated the MW of the silk fibroin using LiBr, Ca(NO3)2 and CaCl2 to dissolve the silk fibers. SDS-PAGE analysis showed that the MW of the CaCl2-derived silk fibroin was lower than the MW produced using LiBr and Ca(NO3)2. In vitro and in vivo degradation results showed that the scaffolds prepared by low-MW silk fibroin were more rapidly degraded. Furthermore, FTIR and amino acid analysis suggested that the amorphous regions were preferentially degraded by Collagenase IA, while the SDS-PAGE and amino acid analysis indicated that the scaffolds were degraded into polypeptides (mainly at 10-30 kDa) and amino acids. Because the CaCl2-derived scaffolds contained abundant low MW polypeptides, inter-intramolecular entanglement and traversing of molecular chains in the crystallites reduced, which resulted in rapid degradation. The in vivo degradation results suggested that the degradation rate of the CaCl2-derived scaffolds was better matched to dermis regeneration, indicating that the degradation rate of silk fibroin can be effectively regulated by changing the MW to achieve a suitable dermal tissue regeneration rate.展开更多
Tissue engineering provides a promising approach for regenerative medicine.The ideal engineered tissue should have the desired structure and functional properties suitable for uniform cell distribution and stable shap...Tissue engineering provides a promising approach for regenerative medicine.The ideal engineered tissue should have the desired structure and functional properties suitable for uniform cell distribution and stable shape fidelity in the full period of in vitro culture and in vivo implantation.However,due to insufficient cell infiltration and inadequate mechanical properties,engineered tissue made from porous scaffolds may have an inconsistent cellular composition and a poor shape retainability,which seriously hinders their further clinical application.In this study,silk fibroin was integrated with silk short fibers with a physical and chemical double-crosslinking network to fabricate fiber-reinforced silk fibroin super elastic absorbent sponges(Fr-SF-SEAs).The Fr-SF-SEAs exhibited the desirable synergistic properties of a honeycomb structure,hygroscopicity and elasticity,which allowed them to undergo an unconventional cyclic compression inoculation method to significantly promote cell diffusion and achieve a uniform cell distribution at a high-density.Furthermore,the regenerated cartilage of the Fr-SF-SEAs scaffold withstood a dynamic pressure environment after subcutaneous implantation and maintained its precise original structure,ultimately achieving human-scale ear-shaped cartilage regeneration.Importantly,the SF-SEAs prepara-tion showed valuable universality in combining chemicals with other bioactive materials or drugs with reactive groups to construct microenvironment bionic scaffolds.The established novel cell inoculation method is highly versatile and can be readily applied to various cells.Based on the design concept of dual-network Fr-SF-SEAs scaffolds,homogenous and mature cartilage was successfully regenerated with precise and complicated shapes,which hopefully provides a platform strategy for tissue engineering for various cartilage defect repairs.展开更多
In order to provide a biomimetic natural extracellular matrix microenvironment with excellent mechanical capacity for tissue regeneration,a novel porous hybrid glycidyl methacrylate-modified silk fibroin/poly(L-lactic...In order to provide a biomimetic natural extracellular matrix microenvironment with excellent mechanical capacity for tissue regeneration,a novel porous hybrid glycidyl methacrylate-modified silk fibroin/poly(L-lactic acid-co-ε-caprolactone)–polyethylene glycol diacrylate(SFMA/P(LLA-CL)–PEGDA)hybrid three-dimensional(3D)nanofibrous scaffolds was successfully fabricated through the combination of 3D nanofibrous platforms and divinyl PEGDA based photocrosslinking,and then further improved water resistance by ethanol vapor post-treatment.Scanning electron microscopy and micro-computed tomography results demonstrated significant PEGDA hydrogel-like matrices bonded nanofibers,which formed a 3D structure similar to that of“steel bar(nanofibers)‒cement(PEGDA)”,with proper pore size,high porosity,and high pore connectivity density.Meanwhile,the hybrid 3D nanofibrous scaffolds showed outstanding swelling properties as well as improved compressive and tensile properties.Furthermore,these hybrid 3D nanofibrous scaffolds could provide a biocompatible microenvironment,capable of inducing the material‒cell hybrid and regulating human umbilical vein endothelial cells proliferation.They thus present significant potential in tissue regeneration.展开更多
文摘In this paper, the main goal is to prepare silk fibroin nano-fiber, which is used for regenerated tissue applications. Silk scaffold nano-fibers made by electro-spinning technology can be used in regenerated tissue applications. The purpose of the research is to prepare a silk-fibroin nano-fiber solution for potential applications in tissue engineering. Using a degumming process, pure silk fibroin protein is extracted from silk cocoons. The protein solution for fibroin is purified, and the protein content is determined. The precise chemical composition, exact temperature, time, voltage, distance, ratio, and humidity all have a huge impact on degumming, solubility, and electro-spinning nano-fibers. The SEM investigates the morphology of silk fibroin nano-fibres at different magnifications. It also reveals the surface condition, fiber orientation, and fiber thickness of the silk fibroin nano-fiber. The results show that regenerated silk fibroin and nano-fiber can be used in silk fibroin scaffolds for various tissue engineering applications.
文摘Regenerative medicine progress is based on the development of cell and tissue bioengineering. One of the aims of tissue engineering is the development of scaffolds, which should substitute the functions of the replaced organ after their implantation into the body. The tissue engineering material must meet a range of requirements, including biocompatibility, mechanical strength, and elasticity. Furthermore, the materials have to be attractive for cell growth: stimulate cell adhesion, migration, proliferation and differentiation. One of the natural biomaterials is silk and its component (silk fibroin). An increasing number of scientists in the world are studying silk and silk fibroin. The purpose of this review article is to provide information about the properties of natural silk (silk fibroin), as well as its manufacture and clinical application of each configuration of silk fibroin in medicine. Materials and research methods. Actual publications of foreign authors on resources PubMed, Medline, E-library have been analyzed. The selection criteria were materials containing information about the structure and components of silk, methods of its production in nature. This article placed strong emphasis on silk fibroin, the ways of artificial modification of it for use in various sphere of medicine.
基金supported by the National Natural Science Foundation of China,No.11672332(to XYC)the National Key Research and Development Plan of China,No.2016YFC1101500(to SZ)
文摘Many studies have shown that bio-scaffolds have important value for promoting axonal regeneration of injured spinal cord.Indeed,cell transplantation and bio-scaffold implantation are considered to be effective methods for neural regeneration.This study was designed to fabricate a type of three-dimensional collagen/silk fibroin scaffold (3D-CF) with cavities that simulate the anatomy of normal spinal cord.This scaffold allows cell growth in vitro and in vivo.To observe the effects of combined transplantation of neural stem cells (NSCs) and 3D-CF on the repair of spinal cord injury.Forty Sprague-Dawley rats were divided into four groups: sham (only laminectomy was performed),spinal cord injury (transection injury of T10 spinal cord without any transplantation),3D-CF (3D scaffold was transplanted into the local injured cavity),and 3D-CF + NSCs (3D scaffold co-cultured with NSCs was transplanted into the local injured cavity.Neuroelectrophysiology,imaging,hematoxylin-eosin staining,argentaffin staining,immunofluorescence staining,and western blot assay were performed.Apart from the sham group,neurological scores were significantly higher in the 3D-CF + NSCs group compared with other groups.Moreover,latency of the 3D-CF + NSCs group was significantly reduced,while the amplitude was significantly increased in motor evoked potential tests.The results of magnetic resonance imaging and diffusion tensor imaging showed that both spinal cord continuity and the filling of injury cavity were the best in the 3D-CF + NSCs group.Moreover,regenerative axons were abundant and glial scarring was reduced in the 3D-CF + NSCs group compared with other groups.These results confirm that implantation of 3D-CF combined with NSCs can promote the repair of injured spinal cord.This study was approved by the Institutional Animal Care and Use Committee of People’s Armed Police Force Medical Center in 2017 (approval No.2017-0007.2).
基金supported by the Scientific Research Project Fund of Wuxi Municipal Health and Family Planning Commission,No.MS201402
文摘Treatment and functional reconstruction after central nervous system injury is a major medical and social challenge. An increasing number of researchers are attempting to use neural stem cells combined with artificial scaffold materials, such as fibroin, for nerve repair. However, such approaches are challenged by ethical and practical issues. Amniotic tissue, a clinical waste product, is abundant, and amniotic epithe- lial cells are pluripotent, have low immunogenicity, and are not the subject of ethical debate. We hypothesized that amniotic epithelial cells combined with silk fibroin scaffolds would be conducive to the repair of spinal cord injury. To test this, we isolated and cultured amniotic epithelial cells, and constructed complexes of these cells and silk fibroin scaffolds. Implantation of the cell-scaffold complex into a rat model of spinal cord injury resulted in a smaller glial scar in the damaged cord tissue than in model rats that received a blank scaffold, or amniotic epithelial cells alone. In addition to a milder local immunological reaction, the rats showed less inflammatory cell infiltration at the trans- plant site, milder host-versus-graft reaction, and a marked improvement in motor function. These findings confirm that the transplantation of amniotic epithelial ceils combined with silk fibroin scaffold can promote the repair of spinal cord injury. Silk fibroin scaffold can provide a good nerve regeneration microenvironment for amniotic epithelial cells.
基金supported by the National Natural Science Foundation of China,No.81671823,81701835a grant from the National Key Research and Development Program of China,No.2016YFC1101603a grant from the Natural Science Research Program of Nantong of China,No.MS12016056
文摘Three dimensional(3D) bioprinting, which involves depositing bioinks(mixed biomaterials) layer by layer to form computer-aided designs, is an ideal method for fabricating complex 3D biological structures. However, it remains challenging to prepare biomaterials with micro-nanostructures that accurately mimic the nanostructural features of natural tissues. A novel nanotechnological tool, electrospinning, permits the processing and modification of proper nanoscale biomaterials to enhance neural cell adhesion, migration, proliferation, differentiation, and subsequent nerve regeneration. The composite scaffold was prepared by combining 3D bioprinting with subsequent electrochemical deposition of polypyrrole and electrospinning of silk fibroin to form a composite polypyrrole/silk fibroin scaffold. Fourier transform infrared spectroscopy was used to analyze scaffold composition. The surface morphology of the scaffold was observed by light microscopy and scanning electron microscopy. A digital multimeter was used to measure the resistivity of prepared scaffolds. Light microscopy was applied to observe the surface morphology of scaffolds immersed in water or Dulbecco's Modified Eagle's Medium at 37℃ for 30 days to assess stability. Results showed characteristic peaks of polypyrrole and silk fibroin in the synthesized conductive polypyrrole/silk fibroin scaffold, as well as the structure of the electrospun nanofiber layer on the surface. The electrical conductivity was 1 × 10^-5–1 × 10^-3 S/cm, while stability was 66.67%. A 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay was employed to measure scaffold cytotoxicity in vitro. Fluorescence microscopy was used to observe Ed U-labeled Schwann cells to quantify cell proliferation. Immunohistochemistry was utilized to detect S100β immunoreactivity, while scanning electron microscopy was applied to observe the morphology of adherent Schwann cells. Results demonstrated that the polypyrrole/silk fibroin scaffold was not cytotoxic and did not affect Schwann cell proliferation. Moreover, filopodia formed on the scaffold and Schwann cells were regularly arranged. Our findings verified that the composite polypyrrole/silk fibroin scaffold has good biocompatibility and may be a suitable material for neural tissue engineering.
基金supported by funds from Huazhong University of Science and Technology,Wuhan,China
文摘Spinal cord injury repair is one of the major challenges in medicine,as it can lead to permanent loss of function of central nervous system and damage to other function of the body.Stem cell transplantation together with tissue engineering is increasingly becoming a potential choice of treatment.However,direct transplantation of stem cells without scaffolds has yielded poor clinical outcome.Here we show a strategy of using mouse embryonic stem cells(ESCs)cultured within a silk fibroin(SF)based,three-dimensional scaffold with oriented channels by a directional temperature field freezing technique and lysophilization.We find that the ESCs maintained proliferation and migrated in the scaffolds and the cells migrated fastest along the SF channels.SF scaffolds contributed to ESC differentiation into neural and glial cell like cells and expressions of the neural and glial cell markers MAP2 and GFAP were greatly elevated when retinoic acid was used as an inducing factor.Our results suggest that this approach may offer some hope in the future for spinal cord injury repair using SF scaffolds and ESCs.
基金Collaborative Innovation Center of Textile and Garment Industry of Henan Province,China(No.hnfz14004)
文摘Besides excellent biodegradability and biocompatibility,a useful tissue engineering scaffold should provide favorable surface properties,outstanding mechanical strength and controlled drug release property. In this paper,a mild process to prepare porous tussah silk fibroin( TSF) scaffolds from aqueous solution was described. The n-butanol was used to control the self-assembly of tussah silk. The scaffolds with different TSF concentrations and the same volume showed differences in pore size and distribution. The maximum porosity of the poprepared porous scaffolds was 80% in this paper. And the pore size of the prepared porous scaffolds with different concentrations was between 10μm and 230 μm. X-ray diffraction( XRD) analysis revealed that amorphous TSF was crystallized to β-sheet secondary structure upon gelatin. The TSF scaffolds for controlled drug release was studied and the result showed that the time of drug release was significantly longer. The produced TSF scaffolds with sustained drug release have potential application in tissue engineering.
基金the Independent Design Project of Key Scientific and Technological Innovation Team of Zhejiang Province,China(No.2010R50012-19)the Key Student Research Training Project of Jiaxing University,China(No.851713022)+1 种基金Technology Commission of JiaxingM unicipality Program,China(No.2012AY1030)National Natural Science Foundation of China(No.31271035)
文摘Vitamin E( VE) is an ideal antioxidant and a stabilizing agent in biological membranes. In this study,silk fibroin( SF) /hydroxybutyl chitosan( HBC) nanofibrous scaffolds are loaded with VE tocopherol polyethylene glycol 1000 succinate( VE TPGS) via electrospinning. SEM images show that the average nanofibrous diameter has no significant difference when the content of VE TPGS increases to 4. 0%( SF / HBC). However,the average nanofibrous diameter decreases largely to 200 nm when the VE TPGS content reaches 6. 0%. Furthermore,VE TPGS presents a sustained release behavior from the nanofibrous scaffolds. Cell viability studies of mouse skin fibroblasts( L929) demonstrate that VE TPGS loaded SF / HBC nanofibrous scaffolds present good cellular compatibility.Moreover,the incorporation of VE TPGS could strengthen the ability of SF / HBC nanofibrous scaffolds on protecting the cells against oxidation stress using the Tertbutyl hydroperoxide( t-BHP)-induced oxidative injury model. Therefore,VE TPGS-loaded SF /HBC nanofibrous scaffolds might be potential candidates for personal skin care,wound dressing and skin tissue engineering scaffolds.
文摘In order to investigate the effect ofArg-Gly-Asp (RGD) peptide-modified silk biomaterial on the adhesion and proliferation of bone marrow-derived mesenchymal stem cells (MSCs), MSCs of third generation were seeded onto the surface of RGD-decorated silk (silk-RGD group), silk alone (silk group) or tissue culture plate (TCP group). After incubation for 4 or 12 h, MSCs were examined quantitatively by using precipitation method for cell attachment. The cell proliferation, which was defined as cell density, was compared among the three groups after culture for 1, 2, 3, and 4 days. Cell skeleton, which was labeled fluorescently, was observed under laser confocal microscope after 24 h of culture. The results showed that cell adhesion rate in silk-RGD group was higher than in silk group (P〈0.05), but similar to that in TCP group after incubation for 4 or 12 h (P〉0.05). There were no sig- nificant differences in the cell proliferation among the three groups at different time points (P〉0.05 for all). Laser confocal microscopy revealed that in silk-RGD group, MSCs, strongly fluorescently stained, spread fully, with stress fibers clearly seen, while in silk group, actin filaments were sparsely aligned and less stress fibers were found. It was concluded that RGD peptide could improve the ad- hesion of MSCs to the silk scaffold, but had no impact on the proliferation of the cells.
文摘Establishing an appropriate degradation rate is critical for tissue engineering scaffolds. In this study, the degradation rate of silk fibroin three-dimensional scaffolds was regulated by changing the molecular weight (MW) of the silk fibroin. The solubility of silk fibroin depends primarily on the ionic ability of the slovent to dissolve silk fibroin, therefore, we regulated the MW of the silk fibroin using LiBr, Ca(NO3)2 and CaCl2 to dissolve the silk fibers. SDS-PAGE analysis showed that the MW of the CaCl2-derived silk fibroin was lower than the MW produced using LiBr and Ca(NO3)2. In vitro and in vivo degradation results showed that the scaffolds prepared by low-MW silk fibroin were more rapidly degraded. Furthermore, FTIR and amino acid analysis suggested that the amorphous regions were preferentially degraded by Collagenase IA, while the SDS-PAGE and amino acid analysis indicated that the scaffolds were degraded into polypeptides (mainly at 10-30 kDa) and amino acids. Because the CaCl2-derived scaffolds contained abundant low MW polypeptides, inter-intramolecular entanglement and traversing of molecular chains in the crystallites reduced, which resulted in rapid degradation. The in vivo degradation results suggested that the degradation rate of the CaCl2-derived scaffolds was better matched to dermis regeneration, indicating that the degradation rate of silk fibroin can be effectively regulated by changing the MW to achieve a suitable dermal tissue regeneration rate.
基金support from the National Key Research and Development Program of China(2018YFC1105800,2017YFC1103900)the National Natural Science Foundation of China(82102211,81871502)+5 种基金the Shanghai Municipal Key Clinical Specialty(shslczdzk06601)the Shanghai Collaborative Innovation Program on Regenerative Medicine and Stem Cell Research(2019CXJQ01)the Key Research and Development Program of Henan Province(No.221111310100)the Major Science and Technology Projects of Xinxiang City(No.21ZD006)the Clinical Research Plan of SHDC(No.SHDC2020CR2045B)the Start-up Funds of Talent Construction and Scientific Research in Shanghai 9th People's Hospital(2021rcyj-ld).
文摘Tissue engineering provides a promising approach for regenerative medicine.The ideal engineered tissue should have the desired structure and functional properties suitable for uniform cell distribution and stable shape fidelity in the full period of in vitro culture and in vivo implantation.However,due to insufficient cell infiltration and inadequate mechanical properties,engineered tissue made from porous scaffolds may have an inconsistent cellular composition and a poor shape retainability,which seriously hinders their further clinical application.In this study,silk fibroin was integrated with silk short fibers with a physical and chemical double-crosslinking network to fabricate fiber-reinforced silk fibroin super elastic absorbent sponges(Fr-SF-SEAs).The Fr-SF-SEAs exhibited the desirable synergistic properties of a honeycomb structure,hygroscopicity and elasticity,which allowed them to undergo an unconventional cyclic compression inoculation method to significantly promote cell diffusion and achieve a uniform cell distribution at a high-density.Furthermore,the regenerated cartilage of the Fr-SF-SEAs scaffold withstood a dynamic pressure environment after subcutaneous implantation and maintained its precise original structure,ultimately achieving human-scale ear-shaped cartilage regeneration.Importantly,the SF-SEAs prepara-tion showed valuable universality in combining chemicals with other bioactive materials or drugs with reactive groups to construct microenvironment bionic scaffolds.The established novel cell inoculation method is highly versatile and can be readily applied to various cells.Based on the design concept of dual-network Fr-SF-SEAs scaffolds,homogenous and mature cartilage was successfully regenerated with precise and complicated shapes,which hopefully provides a platform strategy for tissue engineering for various cartilage defect repairs.
基金This work was sponsored by the Jiaxing Public Welfare Research Project(Grant Nos.2021AY10062 and 2021AY10063)the Zhejiang Provincial Natural Science Foundation of China(Grant Nos.LY20C100003 and LY22C100001)the National Undergraduate Training Program for Innovation and Entrepreneurship(Grant No.202010354009).
文摘In order to provide a biomimetic natural extracellular matrix microenvironment with excellent mechanical capacity for tissue regeneration,a novel porous hybrid glycidyl methacrylate-modified silk fibroin/poly(L-lactic acid-co-ε-caprolactone)–polyethylene glycol diacrylate(SFMA/P(LLA-CL)–PEGDA)hybrid three-dimensional(3D)nanofibrous scaffolds was successfully fabricated through the combination of 3D nanofibrous platforms and divinyl PEGDA based photocrosslinking,and then further improved water resistance by ethanol vapor post-treatment.Scanning electron microscopy and micro-computed tomography results demonstrated significant PEGDA hydrogel-like matrices bonded nanofibers,which formed a 3D structure similar to that of“steel bar(nanofibers)‒cement(PEGDA)”,with proper pore size,high porosity,and high pore connectivity density.Meanwhile,the hybrid 3D nanofibrous scaffolds showed outstanding swelling properties as well as improved compressive and tensile properties.Furthermore,these hybrid 3D nanofibrous scaffolds could provide a biocompatible microenvironment,capable of inducing the material‒cell hybrid and regulating human umbilical vein endothelial cells proliferation.They thus present significant potential in tissue regeneration.