Chemically crosslinked silk fibroin hydrogel with enhanced. Structures, mechanical properties and applications of silk. Silk fibroin is a highly insoluble fibrous protein produced by domestic silk worms bombyx mori. The sequential experimental procedure for protein extraction from bombyx mori silk cocoon has been shown in fig. The silk fibroin bounded to the methylatedfunctionalized. The rcsb pdb also provides a variety of tools and resources. Solution of silk fibroin because sf is coated by sericin, degummimg is very important.
Dialysis method was used to purify the dissolved silk fibroin. Nevertheless, silk fibroin can be rendered anticoagulant via sulfonation, not surprising considering the chemical structure of the natural anticoagulant heparin 24. Figure 11 structure of fibroin and the antiparallel. Protein secondary structure and orientation in silk as. Fibroin is the structural protein of silk fibers, and sericin is the watersoluble glue that binds the fibroin fibers together. Sf can be dissolved with neutral solutions of salts such as liscn, libr, and cacl2 32,33. Mechanical properties of robust ultrathin silk fibroin films. Silk fibroin, derived from bombyx mori cocoons, is a widely used and studied protein polymer for biomaterial applications. Preparation and characterization of silk fibroin as a. J mater sci biocompatible silk fibroin scaffold prepared by reactive inkjet printing patrick rider 2 yu zhang 1 christopher tse 0 yi zhang 0 dharana jayawardane 1 jonathan stringer 0 jill callaghan 2 i. Establishing an appropriate degradation rate is critical for tissue engineering scaffolds. The xrd patterns revealed that its molecular chains are orderly aligned along the axis of the silk fibers fig. Request pdf 3d printing of hierarchical silk fibroin structures like many other natural materials, silk is hierarchically structured from the amino acid level up to the cocoon or spider web. They were collected and frozen in liquid nitrogen and water in.
The electrospinning of regenerated sf was performed with formic acid as a. Sep 22, 2011 silk fibroin, derived from bombyx mori cocoons, is a widely used and studied protein polymer for biomaterial applications. As a member of the wwpdb, the rcsb pdb curates and annotates pdb data according to agreed upon standards. Pdf gellable silk fibroinpolyethylene sponge for hemostasis. Results showed that the purified silk fibroin mainly had irregular curly conformation. Xray diffraction curves of silk fibroin and silk fibroin exposed to different sterilizations were shown in. The fine structure of silk fibroin journal of cell biology. Request pdf structure and solubility of natural silk fibroin the solubility of silk fibroin in aqueoussalt, aqueousorganic, and organic media is analyzed. The crystal structure of fibroin in silk fibers has been investigated by xray diffraction xrd.
A clear fiber diagram was not obtained from xray diffraction pattern of a fcp 1x mat, but were led to assign the following rectangular unit cell to the alpha fibroin. The pdb archive contains information about experimentallydetermined structures of proteins, nucleic acids, and complex assemblies. Influence of film thickness on the surface structure and mineralizationtemplating of silk fibroin wei hao, david porter and zhengzhong shao experimental section aqueous solutions of silk fibroin were obtained through dissolving degummed bombyx mori silk fibers sf with 9. It has a long history of use in medicine, for example, as sutures and artificial ligaments. Silk in its raw state consists of two main proteins, seric. The solubility of silk fibroin in aqueoussalt, aqueousorganic, and organic media is analyzed. In this thesis work, fibroin was processed into a regenerated film and examined for potential biomaterial applications. Fibroin provides the main fibrous structure to the silkworm cocoon while sericin is a glue like. Materials fabrication from bombyx mori silk fibroin nature. Silk sericin ss silk fibroin sf blend nanofibers have been produced by electrospinning in a binary sssf trifluoroacetic acid tfa solution system, which was prepared by mixing 20 wt. Production of silk sericinsilk fibroin blend nanofibers.
The purified silk fibroin was characterized by ftir and thermoanalysis technique. The sf solution was differentiated into droplets which were induced by a syringe needle in the highvoltage electrostatic field. Potential applications of silk fibroin as a biomaterial core. 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, cano32 and cacl2. Waste silk fibers were dissolved in calcium chloride aqueous solution. The amino acid content of sfvf was measured by hitachi83550 amino acid tester. Cox, zanichelli 2006 sericin sericin is the second protein of silk. Smith 0 0 department of mechanical engineering, the university of sheffield, sheffield s1 3jd, uk 1 department of chemical and biological. Structural implications of a remarkable amino acid.
Silk iii is formed principally in solutions of fibroin at an interface i. To improve mechanical properties of fiber, the asspun fibers were postdrawn in 80 vol. The fiber is composed of microcrystalline arrays alternating with amorphous regions. Arrows present the longitudinal axis of the film in the direction of the blade movement. Smith 0 0 department of mechanical engineering, the university of sheffield, sheffield s1 3jd, uk 1 department of. The silk fibroin biofilms can exhibit perfect environmental adaptation for cell growth because of the porous structure of the silk fibroin biofilms. Mar 12, 2017 fibroin is an insoluble protein present in silk created by spiders, the larvae of bombyx mori, other moth genera such as antheraea, cricula, samia and gonometa, and numerous other insects. Materials fabrication from bombyx mori silk fibroin.
The results indicate that the regenerated silk fibroin rsf can be used for fabrication of porous silk fibroin scaffolds for various tissue engineering applications. Fibroin is an insoluble protein present in silk created by spiders, the larvae of bombyx mori, other moth genera such as antheraea, cricula, samia and gonometa, and numerous other insects. Silk fibroin has remarkable mechanical properties when formed into. They were almost the same and all showed a very broad peak at 2 20. Electrospun fibrous membranes are of interest as biomaterials because the increased surface area is favorable for cell adhesion 46, 77. Examination of silk fibers fragmented with ultrasonic radiation and negatively stained revealed the presence of ribbonlike filaments of welldefined lateral dimensions. Higher resolution revealed a granular morphology with lateral granular sizes reaching a fraction of a micrometer fig. An electrospinning process was used to fabricate silk fibroin sf nanofiber nonwovens for wound dressing applications. Together with chemical analysis, it was proposed that the chains are made up of glycine and alanine with occasional substitution by other amino acids. The fine structure of bombyx mori silk fibroin was investigated by electron microscopy and xray diffraction techniques. The goal of this proofofconcept study was the fabrication of porous silk fibroin sf microspheres which could be used as cell culture carriers under very mild processing conditions.
The fine structure of silk fibroin journal of cell. In this study, the degradation rate of silk fibroin threedimensional scaffolds was regulated by changing the molecular weight mw of the silk fibroin. Silk fibroin scaffolds with inverse opal structure for. Structure and solubility of natural silk fibroin springerlink. A novel method to photocrosslink silk fibroin protein is reported, using riboflavin vitamin b2 as a photoinitiator and the mechanism of crosslinking is determined. Mineralizationtemplating of silk fibroin influence of. The morphology and structure of the sls is known to depend on the nature of the ligands 7, their solvatation 8 and on the nanoparticle size 9. Fibroin definition is an insoluble protein comprising the filaments of the raw silk fiber. Control of the gelation process of silk fibroin solution thermal science, year 2014, vol. A hierarchical architecture of micropores and nanofibers was observed inside the scaffolds, and the related structures were analyzed. Silk fibroin based porous materials semantic scholar. The silk fibroin is a natural polymer that has been used.
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. Wxrwicker british cotton industry research association, shirley institute, didsbury, manchester 20, enghtnd received 16 november 1953 and in revised form 1 april 1954 an xray investigation of a precipitate obtained by the action of pancreatic enzymes on an. So, the silk fibroin biofilms are useful in a wide range of medical applications. Isolation of giant silk fibroin polysomes and fibroin mrnp. The structure of silk fibroin fiber from a wild silkworm, samia cynthia ricini. Research on structure and property of silk fibroin. May 22, 2010 the secondary structure of silk fibroin sf and the compatibility of the two components were associated with the carboxymethyl chitosan cmcs content in sfcmcs blend films. The effects of different sterilization methods on silk fibroin. Extraction and characterization of silk fibroin from waste. The results show that the structural distribution of the silk fibroin in crosssection is uniform without significant shellcore structure, which implies that the primary driving force to induce the conformation transition of silk fibroin from random coilhelix to. Spiders produce a variety of silks, and the cloning of genes for silk fibroins reveals a clear link between protein sequence and structureproperty relationships. Silk ii refers to the arrangement of fibroin molecules in spun silk, which has greater strength and is often used in various commercial applications. Silk fibroin has been used to generate fibrous silk membranes from reprocessed native silk fibers or by electrospinning 75, 76.
Direct observation of native silk fibroin conformation in. Research on structure and property of silk fibroin modified. Degummed silk fibroin from bombyx mori silkworm has potential carrier. Circular silk fibroin films o d 16 mm, n d 5 of increasing betasheet content 36 d 4%, 48 d 3, 58 d 4 were obtained by modulating the exposure to waterannealing vapours at 22 c. The fibroins produced in the spiders major ampullate ma gland, which forms the dragline and web frame, contain multiple repeats of motifs that include an 810 residue long poly. The extraction of fibroin protein from bombyx mori silk. Photocrosslinking of silk fibroin using riboflavin for ocular. The surface of the salbl silk fibroin films was relatively smooth, as observed in largescale images fig. The ala is uncharged and its rgroups are small, so it is inclined to form.
This paper reports on the haemostatic properties and mechanism of silk fibroin sf. Biocompatible silk fibroin scaffold prepared by reactive. The changes in the secondary structure of silk fibroin before and after electrospinning were studied by fourier. Structure and solubility of natural silk fibroin request pdf. Together with chemical analysis, it was proposed that the chains are made up of glycine and alanine with occasional substitution by. Recently, silk fibroin has been modified to improve hemocompatibility via addition of zwitterionic. Updated on 24may2018 3ua0 fib heavy chain silkworm 2khm fib3 cterminal spider nmr 2m0m nafib1 residues 250356 nephila antipodiana nmr 2mqa nafib1 rp domain residues 32163 nmr. Highpurity sf fiber can be obtained easily from degummed silk 31. A clear fiber diagram was not obtained from xray diffraction pattern of a fcp 1x mat, but were led to assign the following rectangular unit cell to the alphafibroin. The concentrated solution was stored at 4 c for further study. Users can perform simple and advanced searches based on. While there are multiple ways to separate the sericin and fibroin, one of the more. Mineralizationtemplating of silk fibroin influence of film.
In this paper, a series of testing had been done to study the structure and properties of sfvf. Fibroin is a biopolymer obtained from the cocoons of the bombyx mori silkworm that offers many unique advantages. Silk fibroin scaffolds with inverse opal structure for bone tissue engineering marianne r. Silk sericin sssilk fibroin sf blend nanofibers have been produced by electrospinning in a binary sssf trifluoroacetic acid tfa solution system, which was prepared by mixing 20 wt. Unfortunately, pure silkworm silk fibroin poor hemocompatibility 22, 23. The fibroin protein content of the solution was measured by bradford protein assay. Photocrosslinking of silk fibroin using riboflavin for. Long stretches of silk fibroin are composed of microcrystalline arrays of glyserglyalaglyalan interrupted by regions containing bulkier residues. Pure sf solution is prepared through dialysis for 3 days in. Effect of calcium chloride concentration on silk solubility was studied.
Pdf the amino acid sequence of the heavy chain of bombyx mori silk fibroin was derived from the gene sequence. Structure and properties of silk fibroincarboxymethyl. The strands of the beta sheets run parallel to the fiber axis. This article is from journal of translational medicine, volume 10. Jan 29, 2016 a novel method to photocrosslink silk fibroin protein is reported, using riboflavin vitamin b2 as a photoinitiator and the mechanism of crosslinking is determined. Silk in its raw state consists of two main proteins, sericin and fibroin, with a gluelike layer of sericin coating two singular filaments of fibroin called brins. Factors affecting the formation of the secondary structural organization of fibroin in solutions and in the solid state after the recovery from solutions are analyzed. Silk fibroin modified viscose fiber sfvf was a new fiber with silken handling and luster, which was produced via adding silk fibroin sf during the viscose process. Analysis of the breadths of the equatorial reflections in the xray diffraction. The degradation behavior of silk fibroin derived from. Silk fibroinpoly vinyl alcohol blend scaffolds for. The silk fiber is solubilized into an aqueous fibroin solution, which can then be used as an additive in culture or for producing 3d scaffolds for tissueengineering related studies. The adsorption of bovine serum albumin onto the fibroin film was investigated to.
A new example of biopolymerbased nanocomposites 121 most frequent sl structure is fcc face centered cubic. The silk fibroin scaffolds used for tissue engineering should degrade at a rate that matches the tissue growth rate. Silk fibroin sf, extracted mainly from silkworms, has become a popular biomaterial due to its. As with traditional tissueengineering approaches, the silk scaffolds are typically seeded in vitro with a specific cell type as most cells will adhere to fibroin. These features provided early clues to the utility of regenerated silk fibroin as a scaffoldmatrix for tissue engineering. Potential applications of silk fibroin as a biomaterial. Silk fibroin protein is isolated from middle silk glands and cocoons of different silkworms and is.
This mrnp particle contains biologically active silk fibroin mrna, as judged by cellfree translation in an mrnadependent reticulocyte cellfree system. The fine structure of silk fibroin, the journal of cell. Treatment of giant fibroin polyribosomes with edta releases a particle that sediments at 125s. The secondary structure of silk fibroin sf and the compatibility of the two components were associated with the carboxymethyl chitosan cmcs content in sfcmcs blend films. The polyribosomes contain approximately 45112 ribosomal particles, as judged by electron microscopy. Fibroin is a structural protein of silk fibers and sericins are the watersoluble gluelike. Examination of silk fibers fragmented with ultrasonic radiation and negatively stained revealed the presence of ribbonlike. Nmr and cd studies of bombyx mori silk fibroin revealed the presence of an ordered secondary structure 310. Such properties are attributed to the higherorder structure and primary structure.
Progress in modification of silk fibroin fiber springerlink. Analysis of the breadths of the equatorial reflections in the xray diffraction pattern of fibroin. The diameters of the sssf nanofibers ranged from 33 to 837 nm, and they showed a round. Regenerated silk fibroin rsf fibers were directly dryspun from rsf aqueous solutions into air. This enables integration of cells within the biomaterial. A rather complete conformation transition of sf from random coil to. Silk fibroin degradation related to rheological and. The diameters of the sssf nanofibers ranged from 33 to 837 nm, and they showed a round cross section. Fibroin is an insoluble protein present in silk produced by the larvae of bombyx mori, other moth genera such as antheraea, cricula, samia and gonometa, and numerous other insects. The primary structure of silk is a very simple repetitive domain structure, and this repetitive structure is common to various silks, such as spider pull yarn and wild species, in addition to silk fibroin, produced by b. Silk fibroin sf, a natural macromolecule spun by silkworm bombyx mori, has attracted the interest of scientists of various disciplines for a long time. Silk iii is a newly discovered structure of fibroin. Vetsch,2 jessica leemann,1 ralph muller, 2 andre r. Studart,1 sandra hofmann2,3,4 1department of materials, complex materials, eth zurich, 8093 zurich, switzerland 2department of health science and technology, institute for biomechanics, eth zurich, 8093 zurich, switzerland.
In this study, we treated degummed silk with four kinds of calciumalcohol solutions, and. Silk fibroin has a unique and useful combination of properties, including good biocompatibility and excellent mechanical performance. Information from its description page there is shown below. Degummed silk fibroin from bombyx mori silkworm has potential carrier capabilities for drug delivery in humans.
849 632 825 990 530 53 419 438 523 816 1314 699 1242 635 1219 526 62 753 714 1302 67 191 1126 1296 93 120 933 1159 361 1152 689 131 106 774 897 999 1330 1032