The aim of this study was to prepare silk fibroin/sodium alginate composite film containing curcumin by casting method.Orthogonal test was used to optimize the formulation according to the values of tensile strength a...The aim of this study was to prepare silk fibroin/sodium alginate composite film containing curcumin by casting method.Orthogonal test was used to optimize the formulation according to the values of tensile strength and elongation at break.The release of curcumin in the optimal film was studied in order to explore its application as wound dressing.The results showed that the optimum composition of curcumin/silk fibroin/sodium alginate composite film was as follows:Silk fibroin(70 mg/mL)2.7 g,sodium alginate(24 mg/mL)0.84 g,span 40(5.0 mg/mL)0.4 g,glycerol(3.75%,V/V)3 mL,curcumin(0.2 mg/mL)0.016 g.The optimum film showed the tensile strength and the elongation at break was(0.628±0.032)MPa and(0.794±0.046)%,respectively.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
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
In order to improve the blood compatibility of silk fibroin (SF), poly(ethylene glycol) macromer (PEGM) in different amounts was added to the SF film to incorporate C=C group into the surface of blend films which were...In order to improve the blood compatibility of silk fibroin (SF), poly(ethylene glycol) macromer (PEGM) in different amounts was added to the SF film to incorporate C=C group into the surface of blend films which were then modified by SO2 gas plasma treatment. ATR-FITR and XPS were used to analyze the chemical change which had occurred on the film's surface. When the content of sulfur on the surface of blend films surpasses 1.59%, the antithrombogenicity of plasma treated films increases remarkably due to surface sulfonation. This result implies that SF with blend of PEGM after SO2 plasma treatment have potential use for making blood-contacting biomaterials.展开更多
To obtain water-insoluble silk fibroin (SF) materials, polyethylene glycol diglycidyl ether (PEG-DE) was selected as a crosslinking agent to prepare SF films (blends). The reaction conditions were optimized for ...To obtain water-insoluble silk fibroin (SF) materials, polyethylene glycol diglycidyl ether (PEG-DE) was selected as a crosslinking agent to prepare SF films (blends). The reaction conditions were optimized for the crosslinking of the SF molecules. The hot water stability of the blends was measured using BCA protein assay and gravimetric analysis. The molecular conformation and crystalline structure of the blends were analyzed by FTIR and XRD, respectively. When the mass ratio of SF:PEG-DE was 1.0:0.8, the hot water loss rate of the SF blends was minimized. PEG-DE could induce SF molecules to form fl-sheets during the gel reaction process, resulting in improved crystallinity and hot water dissolved resistance of the blend films. In order to demonstrate the eytotoxicity of the chemical reagents used to crosslink SF, L929 cells were seeded on the blend film (SF:PEG-DE = 1:1) and cultured for 3 days. Cells of L929 readily adhered and spread in the fusiform on the blend film resulting in high cell viability. The extracted liquid from the SF porous film did not inhibit cell proliferation, as estimated by the MTT assay.展开更多
To expand the future clinic applications of biodegradable magnesium alloy,polymer coatings with excellent biocompatibility are the keys to solve the local alkalinity and rapid hydrogen release.Natural-organic silk fib...To expand the future clinic applications of biodegradable magnesium alloy,polymer coatings with excellent biocompatibility are the keys to solve the local alkalinity and rapid hydrogen release.Natural-organic silk fibroin provides an approach to fabricate a protective coating on biomedical Mg-Zn-Ca alloy,however,the adhesion force and mechanical properties of the coating on substrates are ought to be further improved without any chemical conversion/intermediate layer.Hereby,based on VUV/O;surface activation,a hybrid of silk fibroin and sodium alginate is proposed to enhance the adhesion force and mechanical properties of the composite coatings on hydrophilic Mg-Zn-Ca alloy surfaces.Various mass ratios of sodium alginate addition were investigated to achieve the optimum coating strategy.The nanoscratch test and nanoindentation test confirmed that the adhesion force was tripled and mechanical properties index was significantly improved when the mass ratio of silk fibroin/sodium alginate was 70/30 compared to pure silk fibroin or sodium alginate coatings.Meanwhile,the corrosion rate of the coated Mg-Zn-Ca alloy was significantly delayed with the addition of sodium alginate,resulting in a reaction layer during corrosion process.Furthermore,the mechanisms for both adhesion and corrosion processes were discussed in detail.Our findings offer more possibilities for the controllable surface performance of degradable metals.展开更多
In this study, Schwann cells, at a density of 1 x 105 cells/well, were cultured on regenerated silk fibroin nanofibers (305 + 84 nm) prepared using the electrospinning method. Schwann cells cultured on the silk fib...In this study, Schwann cells, at a density of 1 x 105 cells/well, were cultured on regenerated silk fibroin nanofibers (305 + 84 nm) prepared using the electrospinning method. Schwann cells cultured on the silk fibroin nanofibers appeared more ordered, their processes extended further, and they formed more extensive and complex interconnections. In addition, the silk fibroin nanofibers had no impact on the proliferation of Schwann cells or on the secretion of ciliary neurotrophic factor, brain-derived neurotrophic factor or nerve growth factor. These findings indicate that regenerated electrospun silk fibroin nanofibers can promote Schwann cell adhesion, growth and proliferation, and have excellent biocompatibility.展开更多
The potential of combining bioactive glass(MBG) and silk fibroin(SF) together as a new drug delivery system was evaluated. The three-dimensional porous scaffolds were selected as the form of SF, and sol-gel method...The potential of combining bioactive glass(MBG) and silk fibroin(SF) together as a new drug delivery system was evaluated. The three-dimensional porous scaffolds were selected as the form of SF, and sol-gel method was adopted to fabricate MBG in this study. The characteristic of the synthesized material was measured by transmission electron microscopy and scanning electron microscopy. In vitro evaluation of drug delivery was carried out in terms of drug loading and drug release. And aspirin was chosen as the drug for scaffolds to carry out in vitro tests and repair BALB/C mice calvarial defects. Bone formation was examined by microcomputed tomography. The experimental results show that MBG/silk scaffolds have better physiochemical properties compared with silk scaffolds. In comparison to pure silk scaffolds, MBG/silk scaffolds enhance the drug loading efficiency, release rate in vitro and promote bone regeneration in vivo. Thus we conclude that MBG/silk scaffold is a more efficient drug delivery system than pure silk scaffolds.展开更多
To provide materials used in investigating the relationship between amino acid compositions of silk-like protein, structure, and functions, especially the biological functions, the motif genes encoding the silk fibroi...To provide materials used in investigating the relationship between amino acid compositions of silk-like protein, structure, and functions, especially the biological functions, the motif genes encoding the silk fibroin amorphous domain, SGFGPVANGGSGEASSESDFGSSGFGPVANASSGEASSESDFAG(F) were designed and extended using a "head-to-tail" construction strategy. The designed genes were cloned into PSLFA1180FA and multimerized to form structures containing a two-timer, a four-timer, an eight-timer, and a twelve-timer. All the resulting plasmids were digested using the restriction enzyme BamHI and the double-enzymes BglII/HindIII. Restriction enzyme analysis and DNA sequencing revealed the motif was successfully cloned into PSLFA1180FA and multimerized to form a twelve-timer without gene deletion or mutation.展开更多
The mechanical properties and water solubility of electrospinning SF films limit their use as biomaterials. In order to develop a tissue engineering biomaterial with both satisfying biological properties and sufficien...The mechanical properties and water solubility of electrospinning SF films limit their use as biomaterials. In order to develop a tissue engineering biomaterial with both satisfying biological properties and sufficient biomechanical properties,blended films composed of silk fibroin( SF) and poly( ε-caprolactone)( PCL) were fabricated by electrospinning in this study. Scanning electron microscope( SEM), X-ray diffraction( XRD),thermal analysis,Fourier transform-infrared( FT-IR),Raman spectra,mechanical testing,and water solubility were used to characterize the morphological, structural and mechanical properties of the blended electrospinning films. Results showed that the diameter of the blended fiber was distributed between 600 and1000 nm,and the fiber diameter increased as the PCL content increased. There is no obvious phase separation due to the similarity and intermiscibility,as well as the interactions( mainly hydrogen bonds), between the two polymers. Meanwhile, the secondary structures of SF changed from random coils and Silk I to Silk II because of the interactions between SF and PCL. For this reason,the tensile strength and elongation at break of the electrospinning films improved significantly,and the water solubility decreased. In conclusion,the blended electrospinning films fabricated in this study showed satisfying mechanical properties and water insolubilities,and they may be promising biomaterials for applications in tissue engineering for blood vessels,nerve conduits,tendons,ligaments and other tissues.展开更多
We have designed a novel nerve guidance conduit(NGC) made from silk fibroin and poly(lactic-co-glycolic acid) through electrospinning and weaving(ESP-NGCs). Several physical and biological properties of the ESP-...We have designed a novel nerve guidance conduit(NGC) made from silk fibroin and poly(lactic-co-glycolic acid) through electrospinning and weaving(ESP-NGCs). Several physical and biological properties of the ESP-NGCs were assessed in order to evaluate their biocompatibility. The physical properties, including thickness, tensile stiffness, infrared spectroscopy, porosity, and water absorption were determined in vitro. To assess the biological properties, Schwann cells were cultured in ESP-NGC extracts and were assessed by morphological observation, the MTT assay, and immunohistochemistry. In addition, ESP-NGCs were subcutaneously implanted in the backs of rabbits to evaluate their biocompatibility in vivo. The results showed that ESP-NGCs have high porosity, strong hydrophilicity, and strong tensile stiffness. Schwann cells cultured in the ESP-NGC extract fluids showed no significant differences compared to control cells in their morphology or viability. Histological evaluation of the ESP-NGCs implanted in vivo indicated a mild inflammatory reaction and high biocompatibility. Together, these data suggest that these novel ESP-NGCs are biocompatible, and may thus provide a reliable scaffold for peripheral nerve repair in clinical application.展开更多
Pentacene organic field-effect transistors (OFETs) based on single- or double-layer biocompatible dielectrics of poly(methyl methacrylate) (PMMA) and/or silk fibroin (SF) are fabricated. Compared with those de...Pentacene organic field-effect transistors (OFETs) based on single- or double-layer biocompatible dielectrics of poly(methyl methacrylate) (PMMA) and/or silk fibroin (SF) are fabricated. Compared with those devices based on sin- gle PMMA or SF dielectric or SF/PMMA bilayer dielectric, the OFETs with biocompatible PMMA/SF bilayer dielectric exhibit optimal performance with a high field-effect mobility of 0.21 cm2/Vs and a current on/off ratio of 1.5 × 104. By investigating the surface morphology of the pentacene active layer through atom force microscopy and analyzing the elec- trical properties, the performance enhancement is mainly attributed to the crystallization improvement of the pentacene and the smaller interface trap density at the dielectric/organic interface. Meanwhile, a low contact resistance also indicates that a good electrode/organic contact is formed, thereby assisting the performance improvement of the OFET.展开更多
The flexible wearable sensors with excellent stretchability,high sensitivity and good biocompatibility are significantly required for continuously physical condition tracking in health management and rehabilitation mo...The flexible wearable sensors with excellent stretchability,high sensitivity and good biocompatibility are significantly required for continuously physical condition tracking in health management and rehabilitation monitoring.Herein,we present a high-performance wearable sensor.The sensor is prepared with nanocomposite hydrogel by using silk fibroin(SF),polyacrylamide(PAM),polydopamine(PDA)and graphene oxide(GO).It can be used to monitor body motions(including large-scale and small-scale motions)as well as human electrophysiological(ECG)signals with high sensitivity,wide sensing range,and fast response time.Therefore,the proposed sensor is promising in the fields of rehabilitation,motion monitoring and disease diagnosis.展开更多
Silk protein fibroin,as a biomedical material,has good biocompatibility,biodegradability,regulation and excellent physical and chemical properties. In this work,a low density porous silk fibroin material is prepared f...Silk protein fibroin,as a biomedical material,has good biocompatibility,biodegradability,regulation and excellent physical and chemical properties. In this work,a low density porous silk fibroin material is prepared from fibroin solution by high-speed shearing with impeller. By adjusting shear rate of the stirrer,silk fibroin aerogel with different sizes of the aperture is prepared. In general, this aerogel has small porosity, uniform pores, good mechanical properties and slow rate of degradation. It is observed that increasing the shear rate results in higher porosity of aerogel,while the diameter of the aerogel becomes smaller. This silk aerogel may offer a new option as biomaterial for the tissue engineering application based on the information on the structural behaviors.展开更多
This paper mainly introduced the preparation of silk fibroin membranes and their structural change characteristics.Silk fibroin membranes can be used as tissue engineering materials,enzyme-immobilizing membranes,biose...This paper mainly introduced the preparation of silk fibroin membranes and their structural change characteristics.Silk fibroin membranes can be used as tissue engineering materials,enzyme-immobilizing membranes,biosensors and drug controlled-release membranes and other different materials.They have excellent characteristics such as non-toxic,non-polluting and degradable,and thus have broad application prospects.展开更多
Zwitterionic phosphobetaine bearing a hydroxyl and a zwitterionic group,8-hydroxy-2-octyl phosphorylcholine(HOPC),was synthesized and constructed to the surface of silk fibroin(SF) films in order to improve the he...Zwitterionic phosphobetaine bearing a hydroxyl and a zwitterionic group,8-hydroxy-2-octyl phosphorylcholine(HOPC),was synthesized and constructed to the surface of silk fibroin(SF) films in order to improve the hemocompatibility of fibroin films by a an isocyanate head group.The surface characteristics of the modified films were measured by attenuated total reflection Fourier transform infrared spectroscopy(ATR-FTIR) and electron spectroscopy for chemical analysis(ESCA),displaying the successful immobilization of Zwitterionic phosphobetaine on the surface of these fibroin films.Moreover,the further platelet adhesion test in platelets rich plasma(PRP) of human beings showed the zwitterionic phosphobetaine led mainly to good nonthrombogenicity.The experimental results indicated a reasonable approach to improve the blood compatibility of fibroin films.展开更多
The blend film of silk fibroin (SF) and poly(ethylene glycol)400 (PEG400) with a blend ratio of 2/1 (wt/wt) wasprepared simply by dropping a little PEG400 into the SF solution and then casting the mixed aqueous soluti...The blend film of silk fibroin (SF) and poly(ethylene glycol)400 (PEG400) with a blend ratio of 2/1 (wt/wt) wasprepared simply by dropping a little PEG400 into the SF solution and then casting the mixed aqueous solution at 50℃. Theresulting film exhibited much better mechanical properties in the dry and wet state than SF itself, owing to theconformational change of SF in the blends from the random coil to the β-sheet structure and intermolecular hydrogen bondformation between SF and PEG400. Thermogravimetric analysis showed that the initial thermal decomposition temperatureof the blend film was 170℃, which was 80℃ lower than that of SF (250℃) and 20℃ higher than that of PEG400 (150℃),and indicated a Strong interaction between two components of the blend. No crystalline peaks were observed in the X-raydiffraction curve of the blend film. Cell culture test showed that SF/PEG400 was a suitable substrate for the growth of humanumbilical vein endothelial cells (HUVEC).展开更多
A solution-phase approach to the synthesis of nano-Se/silk fibroin colloids(NSeSFC) by reducing selenious acid solution with silk fibroin(SF) was proposed, and the composites were in situ prepared by macrowave met...A solution-phase approach to the synthesis of nano-Se/silk fibroin colloids(NSeSFC) by reducing selenious acid solution with silk fibroin(SF) was proposed, and the composites were in situ prepared by macrowave method. The nanocomposites were characterized with ultraviolet-visible(UV-Vis) absorption spectrometry, resonance Rayleigh scattering(RRS) spectrometry and transmission electron microscopy(TEM). The nano-Se(0) solution exhibited the strongest resonance Rayleigh scattering at 579 rim. Through the RRS discussion, we found the best preparation and conservation condition of NSeSFC. The TEM image shows the sizes of the Se(0) particles were about 50 nm and dispersed equably. The resulted NSeSFC exhibited good stability, and it can be kept for a long period.展开更多
To improve the toughness of silk fibroin( SF) films,poly( ethylene glycol-glycerin)( PEGG) was synthesized with ethylene glycol and epichlorohydrin. The SF / PEGG blend films were prepared by casting aqueous solution ...To improve the toughness of silk fibroin( SF) films,poly( ethylene glycol-glycerin)( PEGG) was synthesized with ethylene glycol and epichlorohydrin. The SF / PEGG blend films were prepared by casting aqueous solution and their structures were characterized. The PEGG was in liquid state at room temperature so it will not be a single phrase at blend film. It crosslinked with SF and made it insolubility in water. The results of X-ray diffraction( XRD) indicated that the crystallinity of the SF in the blend films decreased with the content of PEGG increasing. The tensile strength and elongation at break of blend films were measured using an instron tensile tester. The results showed that the tensile strength and elongation at break of blend films were high enough for application.After the blend films were stored at room temperature for 100 d,the crystallinity, the tensile strength and elongation at wet state increased. The blend films are superior to SF films in providing excellent flexibility and mechanical properties in both dry and wet states. Based on the fact that SF has good biocompatibility,the SF /PEGG blend film will offer new options in many different biomedical applications.展开更多
基金funded by Livelihood Plan Project of Department of Science and Technology of Liaoning Province(2021JH2/10300069,2019-ZD-0845)Department of Education of Liaoning Province(LJKZ0918)National College Students’Innovation and Entrepreneurship Training Program(202210163013).
文摘The aim of this study was to prepare silk fibroin/sodium alginate composite film containing curcumin by casting method.Orthogonal test was used to optimize the formulation according to the values of tensile strength and elongation at break.The release of curcumin in the optimal film was studied in order to explore its application as wound dressing.The results showed that the optimum composition of curcumin/silk fibroin/sodium alginate composite film was as follows:Silk fibroin(70 mg/mL)2.7 g,sodium alginate(24 mg/mL)0.84 g,span 40(5.0 mg/mL)0.4 g,glycerol(3.75%,V/V)3 mL,curcumin(0.2 mg/mL)0.016 g.The optimum film showed the tensile strength and the elongation at break was(0.628±0.032)MPa and(0.794±0.046)%,respectively.
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 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This work was supported by the National Basic Science Research and Development Grants (973) of China (No.G1999064705) and the National High Technology Project (863) of China (No. 2002AA326030).
文摘In order to improve the blood compatibility of silk fibroin (SF), poly(ethylene glycol) macromer (PEGM) in different amounts was added to the SF film to incorporate C=C group into the surface of blend films which were then modified by SO2 gas plasma treatment. ATR-FITR and XPS were used to analyze the chemical change which had occurred on the film's surface. When the content of sulfur on the surface of blend films surpasses 1.59%, the antithrombogenicity of plasma treated films increases remarkably due to surface sulfonation. This result implies that SF with blend of PEGM after SO2 plasma treatment have potential use for making blood-contacting biomaterials.
基金Funded by National Natural Science Foundation of China(Nos.51173125 and 51473108)Natural Science Foundation of Jiangsu Province of China(Nos.BK2012633 and BK2041210)+2 种基金College Natural Science Research Project of Jiangsu Province of China(No.12KJA43004)the Science and Technology Development Foundation of Suzhou of China(Nos.SYG201001 and SS201341)Priority Academic Program Development of Jiangsu Higher Education Institutions[PAPD]
文摘To obtain water-insoluble silk fibroin (SF) materials, polyethylene glycol diglycidyl ether (PEG-DE) was selected as a crosslinking agent to prepare SF films (blends). The reaction conditions were optimized for the crosslinking of the SF molecules. The hot water stability of the blends was measured using BCA protein assay and gravimetric analysis. The molecular conformation and crystalline structure of the blends were analyzed by FTIR and XRD, respectively. When the mass ratio of SF:PEG-DE was 1.0:0.8, the hot water loss rate of the SF blends was minimized. PEG-DE could induce SF molecules to form fl-sheets during the gel reaction process, resulting in improved crystallinity and hot water dissolved resistance of the blend films. In order to demonstrate the eytotoxicity of the chemical reagents used to crosslink SF, L929 cells were seeded on the blend film (SF:PEG-DE = 1:1) and cultured for 3 days. Cells of L929 readily adhered and spread in the fusiform on the blend film resulting in high cell viability. The extracted liquid from the SF porous film did not inhibit cell proliferation, as estimated by the MTT assay.
基金supported by the National Natural Science Foundation of China(Grant No.51975151)the China Postdoctoral Science Foundation(Grant No.2017M610207)+1 种基金the Heilongjiang Provincial Natural Science Foundation of China(Grant No.LH2019E041)the Fundamental Research Funds for Central Universities(Grant No.HIT.NSRIF.2019005)。
文摘To expand the future clinic applications of biodegradable magnesium alloy,polymer coatings with excellent biocompatibility are the keys to solve the local alkalinity and rapid hydrogen release.Natural-organic silk fibroin provides an approach to fabricate a protective coating on biomedical Mg-Zn-Ca alloy,however,the adhesion force and mechanical properties of the coating on substrates are ought to be further improved without any chemical conversion/intermediate layer.Hereby,based on VUV/O;surface activation,a hybrid of silk fibroin and sodium alginate is proposed to enhance the adhesion force and mechanical properties of the composite coatings on hydrophilic Mg-Zn-Ca alloy surfaces.Various mass ratios of sodium alginate addition were investigated to achieve the optimum coating strategy.The nanoscratch test and nanoindentation test confirmed that the adhesion force was tripled and mechanical properties index was significantly improved when the mass ratio of silk fibroin/sodium alginate was 70/30 compared to pure silk fibroin or sodium alginate coatings.Meanwhile,the corrosion rate of the coated Mg-Zn-Ca alloy was significantly delayed with the addition of sodium alginate,resulting in a reaction layer during corrosion process.Furthermore,the mechanisms for both adhesion and corrosion processes were discussed in detail.Our findings offer more possibilities for the controllable surface performance of degradable metals.
基金supported by the Social Development Foundation of Suzhou, No. SYS201034the Open Project Program of Key Laboratory of Eco-Textiles, Ministry of Education, Jiangnan University, No. KLET1005
文摘In this study, Schwann cells, at a density of 1 x 105 cells/well, were cultured on regenerated silk fibroin nanofibers (305 + 84 nm) prepared using the electrospinning method. Schwann cells cultured on the silk fibroin nanofibers appeared more ordered, their processes extended further, and they formed more extensive and complex interconnections. In addition, the silk fibroin nanofibers had no impact on the proliferation of Schwann cells or on the secretion of ciliary neurotrophic factor, brain-derived neurotrophic factor or nerve growth factor. These findings indicate that regenerated electrospun silk fibroin nanofibers can promote Schwann cell adhesion, growth and proliferation, and have excellent biocompatibility.
基金Funded by the National Natural Science Foundation of China(No.81170992)
文摘The potential of combining bioactive glass(MBG) and silk fibroin(SF) together as a new drug delivery system was evaluated. The three-dimensional porous scaffolds were selected as the form of SF, and sol-gel method was adopted to fabricate MBG in this study. The characteristic of the synthesized material was measured by transmission electron microscopy and scanning electron microscopy. In vitro evaluation of drug delivery was carried out in terms of drug loading and drug release. And aspirin was chosen as the drug for scaffolds to carry out in vitro tests and repair BALB/C mice calvarial defects. Bone formation was examined by microcomputed tomography. The experimental results show that MBG/silk scaffolds have better physiochemical properties compared with silk scaffolds. In comparison to pure silk scaffolds, MBG/silk scaffolds enhance the drug loading efficiency, release rate in vitro and promote bone regeneration in vivo. Thus we conclude that MBG/silk scaffold is a more efficient drug delivery system than pure silk scaffolds.
基金National Natural Science Foundation of China(No. 51173125)Natural Science Foundations of Jiangsu Province of China(No. BK2010253,No. BK2012633)+2 种基金College Natural Science Research Project of Jiangsu Province of China(No. 12KJA43004)Science and Technology Plan Foundation of Suzhou of China(No. ZXS2012002)Priority Academic Program Development of Jiangsu Higher Education Institutions,China
文摘To provide materials used in investigating the relationship between amino acid compositions of silk-like protein, structure, and functions, especially the biological functions, the motif genes encoding the silk fibroin amorphous domain, SGFGPVANGGSGEASSESDFGSSGFGPVANASSGEASSESDFAG(F) were designed and extended using a "head-to-tail" construction strategy. The designed genes were cloned into PSLFA1180FA and multimerized to form structures containing a two-timer, a four-timer, an eight-timer, and a twelve-timer. All the resulting plasmids were digested using the restriction enzyme BamHI and the double-enzymes BglII/HindIII. Restriction enzyme analysis and DNA sequencing revealed the motif was successfully cloned into PSLFA1180FA and multimerized to form a twelve-timer without gene deletion or mutation.
基金National Natural Science Foundations of China(No.30970714,No.51103092)Natural Science Foundation of Jiangsu Province,China(No.BK2012634)+1 种基金College Natural Science Research Project of Jiangsu Province,China(No.12KJA430003)Priority Academic Program Development of Jiangsu Higher Education Institutions,China
文摘The mechanical properties and water solubility of electrospinning SF films limit their use as biomaterials. In order to develop a tissue engineering biomaterial with both satisfying biological properties and sufficient biomechanical properties,blended films composed of silk fibroin( SF) and poly( ε-caprolactone)( PCL) were fabricated by electrospinning in this study. Scanning electron microscope( SEM), X-ray diffraction( XRD),thermal analysis,Fourier transform-infrared( FT-IR),Raman spectra,mechanical testing,and water solubility were used to characterize the morphological, structural and mechanical properties of the blended electrospinning films. Results showed that the diameter of the blended fiber was distributed between 600 and1000 nm,and the fiber diameter increased as the PCL content increased. There is no obvious phase separation due to the similarity and intermiscibility,as well as the interactions( mainly hydrogen bonds), between the two polymers. Meanwhile, the secondary structures of SF changed from random coils and Silk I to Silk II because of the interactions between SF and PCL. For this reason,the tensile strength and elongation at break of the electrospinning films improved significantly,and the water solubility decreased. In conclusion,the blended electrospinning films fabricated in this study showed satisfying mechanical properties and water insolubilities,and they may be promising biomaterials for applications in tissue engineering for blood vessels,nerve conduits,tendons,ligaments and other tissues.
基金supported by the National Natural Science Foundation of China,No.81371687,81171457
文摘We have designed a novel nerve guidance conduit(NGC) made from silk fibroin and poly(lactic-co-glycolic acid) through electrospinning and weaving(ESP-NGCs). Several physical and biological properties of the ESP-NGCs were assessed in order to evaluate their biocompatibility. The physical properties, including thickness, tensile stiffness, infrared spectroscopy, porosity, and water absorption were determined in vitro. To assess the biological properties, Schwann cells were cultured in ESP-NGC extracts and were assessed by morphological observation, the MTT assay, and immunohistochemistry. In addition, ESP-NGCs were subcutaneously implanted in the backs of rabbits to evaluate their biocompatibility in vivo. The results showed that ESP-NGCs have high porosity, strong hydrophilicity, and strong tensile stiffness. Schwann cells cultured in the ESP-NGC extract fluids showed no significant differences compared to control cells in their morphology or viability. Histological evaluation of the ESP-NGCs implanted in vivo indicated a mild inflammatory reaction and high biocompatibility. Together, these data suggest that these novel ESP-NGCs are biocompatible, and may thus provide a reliable scaffold for peripheral nerve repair in clinical application.
基金Project supported by the National Natural Science Foundation of China(Grant No.61177032)the Foundation for Innovation Groups of the National Natural Science Foundation of China(Grant No.61021061)+1 种基金the Fundamental Research Funds for the Central Universities,China(Grant No.ZYGX2010Z004)the Scientific Research Staring Foundation for the Returned Overseas Chinese Scholars of the Education Ministry of China(Grant No.GGRYJJ08-05)
文摘Pentacene organic field-effect transistors (OFETs) based on single- or double-layer biocompatible dielectrics of poly(methyl methacrylate) (PMMA) and/or silk fibroin (SF) are fabricated. Compared with those devices based on sin- gle PMMA or SF dielectric or SF/PMMA bilayer dielectric, the OFETs with biocompatible PMMA/SF bilayer dielectric exhibit optimal performance with a high field-effect mobility of 0.21 cm2/Vs and a current on/off ratio of 1.5 × 104. By investigating the surface morphology of the pentacene active layer through atom force microscopy and analyzing the elec- trical properties, the performance enhancement is mainly attributed to the crystallization improvement of the pentacene and the smaller interface trap density at the dielectric/organic interface. Meanwhile, a low contact resistance also indicates that a good electrode/organic contact is formed, thereby assisting the performance improvement of the OFET.
基金Smart Medicine Research Project of Chongqing Medical University in 2020(YJSZHYX202022)Smart Medicine Research Project of Chongqing Medical University(ZHYX2019019)Chongqing Research Program of Basic Research and Frontier Technology(cstc2018jcyjAX0165).
文摘The flexible wearable sensors with excellent stretchability,high sensitivity and good biocompatibility are significantly required for continuously physical condition tracking in health management and rehabilitation monitoring.Herein,we present a high-performance wearable sensor.The sensor is prepared with nanocomposite hydrogel by using silk fibroin(SF),polyacrylamide(PAM),polydopamine(PDA)and graphene oxide(GO).It can be used to monitor body motions(including large-scale and small-scale motions)as well as human electrophysiological(ECG)signals with high sensitivity,wide sensing range,and fast response time.Therefore,the proposed sensor is promising in the fields of rehabilitation,motion monitoring and disease diagnosis.
基金National Natural Science Foundation of China(No.51373114)College Natural Science Research Project of Jiangsu Province,China(No.15KJA540001)
文摘Silk protein fibroin,as a biomedical material,has good biocompatibility,biodegradability,regulation and excellent physical and chemical properties. In this work,a low density porous silk fibroin material is prepared from fibroin solution by high-speed shearing with impeller. By adjusting shear rate of the stirrer,silk fibroin aerogel with different sizes of the aperture is prepared. In general, this aerogel has small porosity, uniform pores, good mechanical properties and slow rate of degradation. It is observed that increasing the shear rate results in higher porosity of aerogel,while the diameter of the aerogel becomes smaller. This silk aerogel may offer a new option as biomaterial for the tissue engineering application based on the information on the structural behaviors.
基金Supported by Chongqing Natural Science Foundation Project(18219)Chongqing Scientific Research Institution Performance Incentive Project(19537,20521)+1 种基金Chongqing Rongchang Agriculture and Animal Husbandry High Tech Industry R&D Special Project(20209)Chongqing Modern Mountain Characteristic Benefit Agriculture(Sericulture)Technology System Diversified Development Research Office(18304).
文摘This paper mainly introduced the preparation of silk fibroin membranes and their structural change characteristics.Silk fibroin membranes can be used as tissue engineering materials,enzyme-immobilizing membranes,biosensors and drug controlled-release membranes and other different materials.They have excellent characteristics such as non-toxic,non-polluting and degradable,and thus have broad application prospects.
基金Funded by the National High Technology Research and Development Program(863) of China (2006AA03Z445)
文摘Zwitterionic phosphobetaine bearing a hydroxyl and a zwitterionic group,8-hydroxy-2-octyl phosphorylcholine(HOPC),was synthesized and constructed to the surface of silk fibroin(SF) films in order to improve the hemocompatibility of fibroin films by a an isocyanate head group.The surface characteristics of the modified films were measured by attenuated total reflection Fourier transform infrared spectroscopy(ATR-FTIR) and electron spectroscopy for chemical analysis(ESCA),displaying the successful immobilization of Zwitterionic phosphobetaine on the surface of these fibroin films.Moreover,the further platelet adhesion test in platelets rich plasma(PRP) of human beings showed the zwitterionic phosphobetaine led mainly to good nonthrombogenicity.The experimental results indicated a reasonable approach to improve the blood compatibility of fibroin films.
基金This work was supported by the National Basic Science Research and Development Grants (973) of China (No. G1999064705).
文摘The blend film of silk fibroin (SF) and poly(ethylene glycol)400 (PEG400) with a blend ratio of 2/1 (wt/wt) wasprepared simply by dropping a little PEG400 into the SF solution and then casting the mixed aqueous solution at 50℃. Theresulting film exhibited much better mechanical properties in the dry and wet state than SF itself, owing to theconformational change of SF in the blends from the random coil to the β-sheet structure and intermolecular hydrogen bondformation between SF and PEG400. Thermogravimetric analysis showed that the initial thermal decomposition temperatureof the blend film was 170℃, which was 80℃ lower than that of SF (250℃) and 20℃ higher than that of PEG400 (150℃),and indicated a Strong interaction between two components of the blend. No crystalline peaks were observed in the X-raydiffraction curve of the blend film. Cell culture test showed that SF/PEG400 was a suitable substrate for the growth of humanumbilical vein endothelial cells (HUVEC).
基金Supported by the National Natural Science Foundation of China(No20775044)the Natural Science Foundation of Shandong Province of China(NoY2006B20)
文摘A solution-phase approach to the synthesis of nano-Se/silk fibroin colloids(NSeSFC) by reducing selenious acid solution with silk fibroin(SF) was proposed, and the composites were in situ prepared by macrowave method. The nanocomposites were characterized with ultraviolet-visible(UV-Vis) absorption spectrometry, resonance Rayleigh scattering(RRS) spectrometry and transmission electron microscopy(TEM). The nano-Se(0) solution exhibited the strongest resonance Rayleigh scattering at 579 rim. Through the RRS discussion, we found the best preparation and conservation condition of NSeSFC. The TEM image shows the sizes of the Se(0) particles were about 50 nm and dispersed equably. The resulted NSeSFC exhibited good stability, and it can be kept for a long period.
基金National Natural Science Foundations of China(Nos.51203107,51373114)the Priority Academic Program Development ofJiangsu Higher Education Institutions,ChinaNatural Science Foundation of Jiangsu Province,China(No.BK20131176)
文摘To improve the toughness of silk fibroin( SF) films,poly( ethylene glycol-glycerin)( PEGG) was synthesized with ethylene glycol and epichlorohydrin. The SF / PEGG blend films were prepared by casting aqueous solution and their structures were characterized. The PEGG was in liquid state at room temperature so it will not be a single phrase at blend film. It crosslinked with SF and made it insolubility in water. The results of X-ray diffraction( XRD) indicated that the crystallinity of the SF in the blend films decreased with the content of PEGG increasing. The tensile strength and elongation at break of blend films were measured using an instron tensile tester. The results showed that the tensile strength and elongation at break of blend films were high enough for application.After the blend films were stored at room temperature for 100 d,the crystallinity, the tensile strength and elongation at wet state increased. The blend films are superior to SF films in providing excellent flexibility and mechanical properties in both dry and wet states. Based on the fact that SF has good biocompatibility,the SF /PEGG blend film will offer new options in many different biomedical applications.