The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Thomas Scheibel - One of the best experts on this subject based on the ideXlab platform.
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in vivo coating of bacterial magnetic nanoparticles by magnetosome expression of Spider Silk inspired peptides
Biomacromolecules, 2018Co-Authors: Frank Mickoleit, Thomas Scheibel, Christian B Borkner, Mauricio Toronahuelpan, Heike M Herold, Denis S Maier, Juergen M Plitzko, Dirk SchülerAbstract:Magnetosomes are natural magnetic nanoparticles with exceptional properties that are synthesized in magnetotactic bacteria by a highly regulated biomineralization process. Their usability in many applications could be further improved by encapsulation in biocompatible polymers. In this study, we explored the production of Spider Silk-inspired peptides on magnetosomes of the alphaproteobacterium Magnetospirillum gryphiswaldense. Genetic fusion of different Silk sequence-like variants to abundant magnetosome membrane proteins enhanced magnetite biomineralization and caused the formation of a proteinaceous capsule, which increased the colloidal stability of isolated particles. Furthermore, we show that Spider Silk peptides fused to a magnetosome membrane protein can be used as seeds for Silk fibril growth on the magnetosome surface. In summary, we demonstrate that the combination of two different biogenic materials generates a genetically encoded hybrid composite with engineerable new properties and enhanced...
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Biofabrication of Cell-Loaded 3D Spider Silk Constructs**
Angewandte Chemie, 2015Co-Authors: Kristin Schacht, Tomasz Jungst, Matthias Schweinlin, Andrea Ewald, Jürgen Groll, Thomas ScheibelAbstract:Biofabrication is an emerging and rapidly expanding field of research in which additive manufacturing techniques in combination with cell printing are exploited to generate hierarchical tissue-like structures. Materials that combine printability with cytocompatibility, so called bioinks, are currently the biggest bottleneck. Since recombinant Spider Silk proteins are non-immunogenic, cytocompatible, and exhibit physical crosslinking, their potential as a new bioink system was evaluated. Cell-loaded Spider Silk constructs can be printed by robotic dispensing without the need for crosslinking additives or thickeners for mechanical stabilization. Cells are able to adhere and proliferate with good viability over at least one week in such Spider Silk scaffolds. Introduction of a cell-binding motif to the Spider Silk protein further enables fine-tuned control over cell–material interactions. Spider Silk hydrogels are thus a highly attractive novel bioink for biofabrication.
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processing of recombinant Spider Silk proteins into tailor made materials for biomaterials applications
Current Opinion in Biotechnology, 2014Co-Authors: Kristin Schacht, Thomas ScheibelAbstract:Spider Silk has extraordinary mechanical properties, is biocompatible and biodegradable, and therefore an ideal material for biomedical applications. However, a drawback for any application is the inhomogeneity of Spider Silk, as seen for other natural materials, as well as the low availability due to the cannibalism of most Spiders. Recently, developed recombinant Spider Silk proteins ensure constant material properties, as well as scalable production, and further the processing into morphologies other than fibres. Biotechnology enables genetic modification, broadening the range of applications, such as implant coatings, scaffolds for tissue engineering, wound dressing devices as well as drug delivery systems.
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Spider Silk Coatings as a Bioshield to Reduce Periprosthetic Fibrous Capsule Formation
Advanced Functional Materials, 2014Co-Authors: Philip H. Zeplin, Lin Romer, Martin C. Jordan, Nathalie C. Maksimovikj, Joachim Nickel, Gregor Lang, Axel Leimer, Thomas ScheibelAbstract:Medical grade silicones have been employed for decades in medical applications. The associated long-term complications, such as capsule formation and contraction have, however, not been fully addressed yet. The aim of this study is to elucidate if capsule formation and/or contraction can be mitigated by veiling the surface of the silicone during the critical phase after implantation. Medical grade silicone implants are homogeneously coated with a micrometer thin layer of recombinant Spider Silk proteins. Biocompatibility analysis in vitro and in vivo focuses on specific physiological reactions. Applying quantitative methods for the determination of marker-specific gene expression and protein concentration, it is detected that the Silk coating inhibits fibroblast proliferation, collagen I synthesis, and differentiation of monocytes into CD68-positive histiocytes. It significantly reduces capsule thickness, post-operative inflammation, synthesis and re-modeling of extracellular matrix, and expression of contracture-mediating factors. Therefore, coatings made of recombinant Spider Silk proteins considerably reduce major post-operative complications associated with implantation of silicone-based alloprosthetics, such as capsular fibrosis and contraction, rendering Spider Silk coatings a bioshield for such implants.
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recombinant production of Spider Silk proteins
Advances in Applied Microbiology, 2013Co-Authors: Aniela Heidebrecht, Thomas ScheibelAbstract:Abstract Natural Spider Silk fibers combine extraordinary properties such as stability and flexibility which results in a toughness superseding that of all other fiber materials. As the Spider’s aggressive territorial behavior renders their farming not feasible, the biotechnological production of Spider Silk proteins (spidroins) is essential in order to investigate and employ them for applications. In order to accomplish this task, two approaches have been tested: firstly, the expression of partial cDNAs, and secondly, the expression of synthetic genes in several host organisms, including bacteria, yeast, plants, insect cells, mammalian cells, and transgenic animals. The experienced problems include genetic instability, limitations of the translational and transcriptional machinery, and low solubility of the produced proteins. Here, an overview of attempts to recombinantly produce spidroins will be given, and advantages and disadvantages of the different approaches and host organisms will be discussed.
David L Kaplan - One of the best experts on this subject based on the ideXlab platform.
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Antimicrobial coating of Spider Silk to prevent bacterial attachment on Silk surgical sutures.
Acta Biomaterialia, 2019Co-Authors: Albina R. Franco, Isabel B Leonor, David L Kaplan, Emanuel M. Fernandes, Márcia T. Rodrigues, Fernando Rodrigues, Manuela E. Gomes, Rui L. ReisAbstract:Abstract Microbial infections from post-surgery or other medical-related procedure is a serious health problem. Nowadays, the research is focused on the development of new drug-free materials with antibacterial properties to prevent or minimize the risk of infections. Spider Silk is known for its unique biomechanical properties allied with biocompatibility. Recombinant DNA technology allows to bioengineering Spider Silk with antimicrobial peptides (AMP). Thus, our goal was to bioengineered Spider Silk proteins with AMP (6mer-HNP1) as an antibacterial drug-free coating for commercial Silk sutures (Perma-Hand®) for decreasing bacterial infections. Perma-Hand® sutures were coated with 6mer-HNP1 by dip coating. In vitro tests, using human fetal lung fibroblasts (MRC5), showed that coated sutures sustained cell viability, and also, the contact with red blood cells (RBCs) demonstrate blood compatibility. Also, the coatings inhibited significantly the adherence and formation of biofilm, where sutures coated with 6mer-HNP1 produced a 1.5 log reduction of Methicillin-Resistant Staphylococcus aureus (MRSA) and a 2 log reduction of Escherichia coli (E. coli) compared to the uncoated Perma-Hand® suture. The mechanical properties of Perma-Hand® sutures were not affected by the presence of bioengineered Spider Silk proteins. Thus, the present work demonstrated that using Spider Silk drug-free coatings it is possible to improve the antibacterial properties of the commercial sutures. Furthermore, a new class of drug-free sutures for reducing post-implantation infections can be developed. Statement of Significance Microbial infections from post-surgery or other medical-related procedure is a serious health problem. Developing new drug-free materials with antibacterial properties is an approach to prevent or minimize the risk of infections. Spider Silk is known for its unique biomechanical properties allied with biocompatibility. Recombinant DNA technology allow to bioengineering Spider Silk with antimicrobial peptides (AMP). Our goal is bioengineered Spider Silk proteins with AMP as an antibacterial coating for Silk sutures. The coatings showed exceptional antibacterial properties and maintained intrinsic mechanical features. In vitro studies showed a positive effect of the coated sutures on the cell behavior. With this new drug-free bioengineered Spider Silk coating is possible to develop a new class of drug-free sutures for reducing post-implantation infections.
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conformation and dynamics of soluble repetitive domain elucidates the initial β sheet formation of Spider Silk
Nature Communications, 2018Co-Authors: Nur Alia Oktaviani, David L Kaplan, Akimasa Matsugami, Ali D Malay, F Hayashi, Keiji NumataAbstract:The β-sheet is the key structure underlying the excellent mechanical properties of Spider Silk. However, the comprehensive mechanism underlying β-sheet formation from soluble Silk proteins during the transition into insoluble stable fibers has not been elucidated. Notably, the assembly of repetitive domains that dominate the length of the protein chains and structural features within the spun fibers has not been clarified. Here we determine the conformation and dynamics of the soluble precursor of the repetitive domain of Spider Silk using solution-state NMR, far-UV circular dichroism and vibrational circular dichroism. The soluble repetitive domain contains two major populations: ~65% random coil and ~24% polyproline type II helix (PPII helix). The PPII helix conformation in the glycine-rich region is proposed as a soluble prefibrillar region that subsequently undergoes intramolecular interactions. These findings unravel the mechanism underlying the initial step of β-sheet formation, which is an extremely rapid process during Spider Silk assembly.
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bioengineered chimeric Spider Silk uranium binding proteins
Macromolecular Bioscience, 2013Co-Authors: Sreevidhya Krishnaji, David L KaplanAbstract:Heavy metals constitute a source of environmental pollution. Here, novel functional hybrid biomaterials for specific interactions with heavy metals are designed by bioengineering consensus sequence repeats from Spider Silk of Nephila clavipes with repeats of a uranium peptide recognition motif from a mutated 33-residue of calmodulin protein from Paramecium tetraurelia. The self-assembly features of the Silk to control nanoscale organic/inorganic material interfaces provides new biomaterials for uranium recovery. With subsequent enzymatic digestion of the Silk to concentrate the sequestered metals, options can be envisaged to use these new chimeric protein systems in environmental engineering, including to remediate environments contaminated by uranium.
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Purification and cytotoxicity of tag-free bioengineered Spider Silk proteins.
Journal of Biomedical Materials Research Part A, 2012Co-Authors: Hanna Dams-kozlowska, Paulina Tomasiewicz, Jolanta Lozinska, Agnieszka Majer, David L Kaplan, Andrzej MackiewiczAbstract:Bioengineered Spider Silk-like proteins can serve as biomaterials for various biomedical applications. These proteins can be assembled in several morphological forms such as films, microcapsules, spheres, fibers, gels and scaffolds. However, crucial points for recombinant Spider Silks for human use are toxicity and immunogenicity. To assess this issue two bioengineered Spider Silk proteins composed of different numbers of repetitive motifs of the consensus repeats from spidroin-1 from Nephila clavipes (15X and 6X) were cloned and expressed in E. coli. The proteins were free of tag-sequence and were purified using two methods based on (i) thermal and (ii) organic acid resistance of the Spider Silks. The soluble Spider Silk proteins were not cytotoxic and did not activate macrophages over a wide range of concentrations, except when present at the highest concentration. Films made of the different Silk variants supported the growth of the cells. Based on these data, and since the biodegradation rate of Silk is very slow, the bioengineered Spider Silks are presumed safe biomaterials for biomedical applications.
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antimicrobial functionalized genetically engineered Spider Silk
Biomaterials, 2011Co-Authors: Silvia Gomes, João Filipe Mano, Isabel B Leonor, Rui L. Reis, David L KaplanAbstract:Genetically engineered fusion proteins offer potential as multifunctional biomaterials for medical use. Fusion or chimeric proteins can be formed using recombinant DNA technology by combining nucleotide sequences encoding different peptides or proteins that are otherwise not found together in nature. In the present study, three new fusion proteins were designed, cloned and expressed and assessed for function, by combining the consensus sequence of dragline Spider Silk with three different antimicrobial peptides. The human antimicrobial peptides human neutrophil defensin 2 (HNP-2), human neutrophil defensins 4 (HNP-4) and hepcidin were fused to Spider Silk through bioengineering. The Spider Silk domain maintained its self-assembly features, a key aspect of these new polymeric protein biomaterials, allowing the formation of b-sheets to lock in structures via physical interactions without the need for chemical crosslinking. These new functional Silk proteins were assessed for antimicrobial activity against Gram e Escherichia coli and Gram þ Staphylococcus aureus and microbicidal activity was demonstrated. Dynamic light scattering was used to assess protein aggregation to clarify the antimicrobial patterns observed. Attenuated-total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and circular dichroism (CD) were used to assess the secondary structure of the new recombinant proteins. In vitro cell studies with a human osteosarcoma cell line (SaOs-2) demonstrated the compatibility of these new proteins with mammalian cells.
Peter M. Vogt - One of the best experts on this subject based on the ideXlab platform.
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Interactions between Spider Silk and Cells – NIH/3T3 Fibroblasts Seeded on Miniature Weaving Frames
2013Co-Authors: Joern W. Kuhbier, Christina Allmeling, Anja Hillmer, Merlin Guggenheim, Kerstin Reimers, Cornelia Kasper, Peter M. VogtAbstract:Background: Several materials have been used for tissue engineering purposes, since the ideal matrix depends on the desired tissue. Silk biomaterials have come to focus due to their great mechanical properties. As untreated Silkworm Silk has been found to be quite immunogenic, an alternative could be Spider Silk. Not only does it own unique mechanical properties, its biocompatibility has been shown already in vivo. In our study, we used native Spider dragline Silk which is known as the strongest fibre in nature. Methodology/Principal Findings: Steel frames were originally designed and manufactured and woven with Spider Silk, harvesting dragline Silk directly out of the animal. After sterilization, scaffolds were seeded with fibroblasts to analyse cell proliferation and adhesion. Analysis of cell morphology and actin filament alignment clearly revealed adherence. Proliferation was measured by cell count as well as determination of relative fluorescence each after 1, 2, 3, and 5 days. Cell counts for native Spider Silk were also compared with those for trypsin-digested Spider Silk. Spider Silk specimens displayed less proliferation than collagen- and fibronectin-coated cover slips, enzymatic treatment reduced adhesion and proliferation rates tendentially though not significantly. Nevertheless, proliferation could be proven with high significance (p,0.01). Conclusion/Significance: Native Spider Silk does not require any modification to its application as a biomaterial that can rival any artificial material in terms of cell growth promoting properties. We could show adhesion mechanics on intracellula
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First investigation of Spider Silk as a braided microsurgical suture
Journal of Biomedical Materials Research Part B, 2011Co-Authors: Joern W. Kuhbier, Christina Allmeling, Anja Hillmer, Björn Menger, Kerstin Reimers, Cornelia Kasper, Peter M. Vogt, Christine RadtkeAbstract:Inhibition of axonal outgrowth accompanied by neuroma formation appears in microsurgical nerve repair as reaction to common microsuture materials like Silk, nylon, or polyglycolic acid. In contrast, recent findings revealed advan- tages of Spider Silk fibers in guiding Schwann cells in nerve regeneration. Here, we asked if we could braid microsutures from native Spider Silk fibers. Microsutures braided of native Spider dragline Silk were manufactured, containing either 2 � 15 or 3 � 10 single fibres strands. Morphologic appearance was studied and tensile strength and stress-strain ratio (SSR) were calculated. The constructed Spider Silk sutures showed a median thickness of 25 lm, matching the USP definition of 10-0. Maximum load and tensile strength for both Spider Silk microsutures were significantly more than 2-fold higher than for nylon suture; SSR was 1.5-fold higher. All values except elasticity were higher in 3 � 10 strand sutures compared to 2 � 15 strand sutures, but not significantly. In this pilot study, we demonstrate the successful manufacture of microsutures from Spider Silk. With regards to the mechanical properties, these sutures were superior to nylon sutures. As Spider Silk displays high biocompatibility in nerve regeneration, its usage in microsurgical nerve repair should be considered. V C
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interactions between Spider Silk and cells nih 3t3 fibroblasts seeded on miniature weaving frames
PLOS ONE, 2010Co-Authors: Joern W. Kuhbier, Christina Allmeling, Anja Hillmer, Bjoern Menger, Gudrun Brandes, Merlin Guggenheim, Kerstin Reimers, Cornelia Kasper, Peter M. VogtAbstract:Background Several materials have been used for tissue engineering purposes, since the ideal matrix depends on the desired tissue. Silk biomaterials have come to focus due to their great mechanical properties. As untreated Silkworm Silk has been found to be quite immunogenic, an alternative could be Spider Silk. Not only does it own unique mechanical properties, its biocompatibility has been shown already in vivo. In our study, we used native Spider dragline Silk which is known as the strongest fibre in nature. Methodology/Principal Findings Steel frames were originally designed and manufactured and woven with Spider Silk, harvesting dragline Silk directly out of the animal. After sterilization, scaffolds were seeded with fibroblasts to analyse cell proliferation and adhesion. Analysis of cell morphology and actin filament alignment clearly revealed adherence. Proliferation was measured by cell count as well as determination of relative fluorescence each after 1, 2, 3, and 5 days. Cell counts for native Spider Silk were also compared with those for trypsin-digested Spider Silk. Spider Silk specimens displayed less proliferation than collagen- and fibronectin-coated cover slips, enzymatic treatment reduced adhesion and proliferation rates tendentially though not significantly. Nevertheless, proliferation could be proven with high significance (p<0.01). Conclusion/Significance Native Spider Silk does not require any modification to its application as a biomaterial that can rival any artificial material in terms of cell growth promoting properties. We could show adhesion mechanics on intracellular level. Additionally, proliferation kinetics were higher than in enzymatically digested controls, indicating that Spider Silk does not require modification. Recent findings concerning reduction of cell proliferation after exposure could not be met. As biotechnological production of the hierarchical composition of native Spider Silk fibres is still a challenge, our study has a pioneer role in researching cellular mechanics on native Spider Silk fibres.
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Spider Silk fibres in artificial nerve constructs promote peripheral nerve regeneration
Cell Proliferation, 2008Co-Authors: Christina Allmeling, Gudrun Brandes, Merlin Guggenheim, S Kall, Andreas Jokuszies, C.-y. Choi, Kerstin Reimers, Cornelia Kasper, Peter M. VogtAbstract:OBJECTIVE: In our study, we describe the use of Spider Silk fibres as a new material in nerve tissue engineering, in a 20-mm sciatic nerve defect in rats. MATERIALS AND METHODS: We compared isogenic nerve grafts to vein grafts with Spider Silk fibres, either alone or supplemented with Schwann cells, or Schwann cells and matrigel. Controls, consisting of veins and matrigel, were transplanted. After 6 months, regeneration was evaluated for clinical outcome, as well as for histological and morphometrical performance. RESULTS: Nerve regeneration was achieved with isogenic nerve grafts as well as with all constructs, but not in the control group. Effective regeneration by isogenic nerve grafts and grafts containing Spider Silk was corroborated by diminished degeneration of the gastrocnemius muscle and by good histological evaluation results. Nerves stained for S-100 and neurofilament indicated existence of Schwann cells and axonal re-growth. Axons were aligned regularly and had a healthy appearance on ultrastructural examination. Interestingly, in contrast to recently published studies, we found that bridging an extensive gap by cell-free constructs based on vein and Spider Silk was highly effective in nerve regeneration. CONCLUSION: We conclude that Spider Silk is a viable guiding material for Schwann cell migration and proliferation as well as for axonal re-growth in a long-distance model for peripheral nerve regeneration.
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use of Spider Silk fibres as an innovative material in a biocompatible artificial nerve conduit
Journal of Cellular and Molecular Medicine, 2006Co-Authors: Christina Allmeling, S Kall, Andreas Jokuszies, Kerstin Reimers, Peter M. VogtAbstract:Defects of peripheral nerves still represent a challenge for surgical nerve reconstruction. Recent studies concentrated on replacement by artificial nerve conduits from different synthetic or biological materials. In our study, we describe for the first time the use of Spider Silk fibres as a new material in nerve tissue engineering. Schwann cells (SC) were cultivated on Spider Silk fibres. Cells adhered quickly on the fibres compared to polydioxanone monofilaments (PDS). SC survival and proliferation was normal in Live/Dead assays. The Silk fibres were ensheathed completely with cells. We developed composite nerve grafts of acellularized veins, Spider Silk fibres and SC diluted in matrigel. These artificial nerve grafts could be cultivated in vitro for one week. Histological analysis showed that the cells were vital and formed distinct columns along the Silk fibres. In conclusion, our results show that artificial nerve grafts can be constructed successfully from Spider Silk, acellularized veins and SC mixed with matrigel.
Jan Johansson - One of the best experts on this subject based on the ideXlab platform.
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sterilized recombinant Spider Silk fibers of low pyrogenicity
Biomacromolecules, 2010Co-Authors: My Hedhammar, Sonja Von Aulock, Hanna Bramfeldt, Teodora Baris, Mona Widhe, Glareh Askarieh, Kerstin Nordling, Jan JohanssonAbstract:We have recently shown that it is possible to recombinantly produce a miniature Spider Silk protein, 4RepCT, that spontaneously self-assembles into mechanically stable macroscopic fibers (Stark, M.; Grip, S.; Rising, A.; Hedhammar, M.; Engstrom, W.; Hjalm, G.; Johansson, J. Macroscopic fibers self-assembled from recombinant miniature Spider Silk proteins. Biomacromolecules 2007, 8 (5), 1695−1701). When produced as a soluble fusion protein (with thioredoxin) in Escherichia coli, the Spider Silk protein can be subjected to several purification steps without aggregating. Here, combined purification and endotoxin removal is achieved using a simple cell wash procedure, protein affinity purification, and LPS depletion. No toxic chemicals were included in the process and the protein retained its ability to self-assemble into fibers. With this method, fibers with pyrogenicity corresponding to less than 1 EU/mg could be recovered. Moreover, the fibers could be sterilized through autoclaving with retained morpholog...
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macroscopic fibers self assembled from recombinant miniature Spider Silk proteins
Biomacromolecules, 2007Co-Authors: Margareta Stark, Anna Rising, Stefan Grip, Wilhelm Engstrom, Goran Hjalm, My Hedhammar, Jan JohanssonAbstract:Strength, elasticity, and biocompatibility make Spider Silk an attractive resource for the production of artificial biomaterials. Spider Silk proteins, spidroins, contain hundreds of repeated poly alanine/glycine-rich blocks and are difficult to produce recombinantly in soluble form. Most previous attempts to produce artificial Spider Silk fibers have included solubilization steps in nonphysiological solvents. It is here demonstrated that a miniature spidroin from a protein in dragline Silk of Euprosthenops australis can be produced in a soluble form in Escherichia coli when fused to a highly soluble protein partner. Although this miniature spidroin contains only four poly alanine/glycine-rich blocks followed by a C-terminal non-repetitive domain, meter-long fibers are spontaneously formed after proteolytic release of the fusion partner. The structure of the fibers is similar to that of dragline Silks, and although self-assembled from recombinant proteins they are as strong as fibers spun from redissolved...
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macroscopic fibers self assembled from recombinant miniature Spider Silk proteins
Biomacromolecules, 2007Co-Authors: Margareta Stark, Anna Rising, Stefan Grip, Wilhelm Engstrom, Goran Hjalm, My Hedhammar, Jan JohanssonAbstract:Strength, elasticity, and biocompatibility make Spider Silk an attractive resource for the production of artificial biomaterials. Spider Silk proteins, spidroins, contain hundreds of repeated poly alanine/glycine-rich blocks and are difficult to produce recombinantly in soluble form. Most previous attempts to produce artificial Spider Silk fibers have included solubilization steps in nonphysiological solvents. It is here demonstrated that a miniature spidroin from a protein in dragline Silk of Euprosthenops australis can be produced in a soluble form in Escherichia coli when fused to a highly soluble protein partner. Although this miniature spidroin contains only four poly alanine/glycine-rich blocks followed by a C-terminal non-repetitive domain, meter-long fibers are spontaneously formed after proteolytic release of the fusion partner. The structure of the fibers is similar to that of dragline Silks, and although self-assembled from recombinant proteins they are as strong as fibers spun from redissolved Silk. Moreover, the fibers appear to be biocompatible because human tissue culture cells can grow on and attach to the fibers. These findings enable controlled production of high-performance biofibers at large scale under physiological conditions.
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n terminal nonrepetitive domain common to dragline flagelliform and cylindriform Spider Silk proteins
Biomacromolecules, 2006Co-Authors: Anna Rising, Wilhelm Engstrom, Goran Hjalm, Jan JohanssonAbstract:Spider Silk has been extensively studied for its outstanding mechanical properties. Partial intermediate and C-terminal sequences of different Spider Silk proteins have been determined, and during the past decade also N-terminal domains have been characterized. However, only some of these N-terminal domains have been reported to contain signal peptides, leaving the mechanism whereby they enter the secretory pathway open to speculation. Here we present the sequence of a 394-residue N-terminal region of the Euprosthenops australis major ampullate spidroin 1 (MaSp1). A close comparison with published sequences from other species revealed the presence of N-terminal signal peptides followed by an approximately 130-residue nonrepetitive domain. From secondary structure predictions, helical wheel analysis, and circular dichroism spectroscopy this domain is concluded to contain five α-helices and is a conserved constituent of hitherto analyzed dragline, flagelliform, and cylindriform Spider Silk proteins.
Christina Allmeling - One of the best experts on this subject based on the ideXlab platform.
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Interactions between Spider Silk and Cells – NIH/3T3 Fibroblasts Seeded on Miniature Weaving Frames
2013Co-Authors: Joern W. Kuhbier, Christina Allmeling, Anja Hillmer, Merlin Guggenheim, Kerstin Reimers, Cornelia Kasper, Peter M. VogtAbstract:Background: Several materials have been used for tissue engineering purposes, since the ideal matrix depends on the desired tissue. Silk biomaterials have come to focus due to their great mechanical properties. As untreated Silkworm Silk has been found to be quite immunogenic, an alternative could be Spider Silk. Not only does it own unique mechanical properties, its biocompatibility has been shown already in vivo. In our study, we used native Spider dragline Silk which is known as the strongest fibre in nature. Methodology/Principal Findings: Steel frames were originally designed and manufactured and woven with Spider Silk, harvesting dragline Silk directly out of the animal. After sterilization, scaffolds were seeded with fibroblasts to analyse cell proliferation and adhesion. Analysis of cell morphology and actin filament alignment clearly revealed adherence. Proliferation was measured by cell count as well as determination of relative fluorescence each after 1, 2, 3, and 5 days. Cell counts for native Spider Silk were also compared with those for trypsin-digested Spider Silk. Spider Silk specimens displayed less proliferation than collagen- and fibronectin-coated cover slips, enzymatic treatment reduced adhesion and proliferation rates tendentially though not significantly. Nevertheless, proliferation could be proven with high significance (p,0.01). Conclusion/Significance: Native Spider Silk does not require any modification to its application as a biomaterial that can rival any artificial material in terms of cell growth promoting properties. We could show adhesion mechanics on intracellula
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First investigation of Spider Silk as a braided microsurgical suture
Journal of Biomedical Materials Research Part B, 2011Co-Authors: Joern W. Kuhbier, Christina Allmeling, Anja Hillmer, Björn Menger, Kerstin Reimers, Cornelia Kasper, Peter M. Vogt, Christine RadtkeAbstract:Inhibition of axonal outgrowth accompanied by neuroma formation appears in microsurgical nerve repair as reaction to common microsuture materials like Silk, nylon, or polyglycolic acid. In contrast, recent findings revealed advan- tages of Spider Silk fibers in guiding Schwann cells in nerve regeneration. Here, we asked if we could braid microsutures from native Spider Silk fibers. Microsutures braided of native Spider dragline Silk were manufactured, containing either 2 � 15 or 3 � 10 single fibres strands. Morphologic appearance was studied and tensile strength and stress-strain ratio (SSR) were calculated. The constructed Spider Silk sutures showed a median thickness of 25 lm, matching the USP definition of 10-0. Maximum load and tensile strength for both Spider Silk microsutures were significantly more than 2-fold higher than for nylon suture; SSR was 1.5-fold higher. All values except elasticity were higher in 3 � 10 strand sutures compared to 2 � 15 strand sutures, but not significantly. In this pilot study, we demonstrate the successful manufacture of microsutures from Spider Silk. With regards to the mechanical properties, these sutures were superior to nylon sutures. As Spider Silk displays high biocompatibility in nerve regeneration, its usage in microsurgical nerve repair should be considered. V C
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interactions between Spider Silk and cells nih 3t3 fibroblasts seeded on miniature weaving frames
PLOS ONE, 2010Co-Authors: Joern W. Kuhbier, Christina Allmeling, Anja Hillmer, Bjoern Menger, Gudrun Brandes, Merlin Guggenheim, Kerstin Reimers, Cornelia Kasper, Peter M. VogtAbstract:Background Several materials have been used for tissue engineering purposes, since the ideal matrix depends on the desired tissue. Silk biomaterials have come to focus due to their great mechanical properties. As untreated Silkworm Silk has been found to be quite immunogenic, an alternative could be Spider Silk. Not only does it own unique mechanical properties, its biocompatibility has been shown already in vivo. In our study, we used native Spider dragline Silk which is known as the strongest fibre in nature. Methodology/Principal Findings Steel frames were originally designed and manufactured and woven with Spider Silk, harvesting dragline Silk directly out of the animal. After sterilization, scaffolds were seeded with fibroblasts to analyse cell proliferation and adhesion. Analysis of cell morphology and actin filament alignment clearly revealed adherence. Proliferation was measured by cell count as well as determination of relative fluorescence each after 1, 2, 3, and 5 days. Cell counts for native Spider Silk were also compared with those for trypsin-digested Spider Silk. Spider Silk specimens displayed less proliferation than collagen- and fibronectin-coated cover slips, enzymatic treatment reduced adhesion and proliferation rates tendentially though not significantly. Nevertheless, proliferation could be proven with high significance (p<0.01). Conclusion/Significance Native Spider Silk does not require any modification to its application as a biomaterial that can rival any artificial material in terms of cell growth promoting properties. We could show adhesion mechanics on intracellular level. Additionally, proliferation kinetics were higher than in enzymatically digested controls, indicating that Spider Silk does not require modification. Recent findings concerning reduction of cell proliferation after exposure could not be met. As biotechnological production of the hierarchical composition of native Spider Silk fibres is still a challenge, our study has a pioneer role in researching cellular mechanics on native Spider Silk fibres.
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Spider Silk fibres in artificial nerve constructs promote peripheral nerve regeneration
Cell Proliferation, 2008Co-Authors: Christina Allmeling, Gudrun Brandes, Merlin Guggenheim, S Kall, Andreas Jokuszies, C.-y. Choi, Kerstin Reimers, Cornelia Kasper, Peter M. VogtAbstract:OBJECTIVE: In our study, we describe the use of Spider Silk fibres as a new material in nerve tissue engineering, in a 20-mm sciatic nerve defect in rats. MATERIALS AND METHODS: We compared isogenic nerve grafts to vein grafts with Spider Silk fibres, either alone or supplemented with Schwann cells, or Schwann cells and matrigel. Controls, consisting of veins and matrigel, were transplanted. After 6 months, regeneration was evaluated for clinical outcome, as well as for histological and morphometrical performance. RESULTS: Nerve regeneration was achieved with isogenic nerve grafts as well as with all constructs, but not in the control group. Effective regeneration by isogenic nerve grafts and grafts containing Spider Silk was corroborated by diminished degeneration of the gastrocnemius muscle and by good histological evaluation results. Nerves stained for S-100 and neurofilament indicated existence of Schwann cells and axonal re-growth. Axons were aligned regularly and had a healthy appearance on ultrastructural examination. Interestingly, in contrast to recently published studies, we found that bridging an extensive gap by cell-free constructs based on vein and Spider Silk was highly effective in nerve regeneration. CONCLUSION: We conclude that Spider Silk is a viable guiding material for Schwann cell migration and proliferation as well as for axonal re-growth in a long-distance model for peripheral nerve regeneration.
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use of Spider Silk fibres as an innovative material in a biocompatible artificial nerve conduit
Journal of Cellular and Molecular Medicine, 2006Co-Authors: Christina Allmeling, S Kall, Andreas Jokuszies, Kerstin Reimers, Peter M. VogtAbstract:Defects of peripheral nerves still represent a challenge for surgical nerve reconstruction. Recent studies concentrated on replacement by artificial nerve conduits from different synthetic or biological materials. In our study, we describe for the first time the use of Spider Silk fibres as a new material in nerve tissue engineering. Schwann cells (SC) were cultivated on Spider Silk fibres. Cells adhered quickly on the fibres compared to polydioxanone monofilaments (PDS). SC survival and proliferation was normal in Live/Dead assays. The Silk fibres were ensheathed completely with cells. We developed composite nerve grafts of acellularized veins, Spider Silk fibres and SC diluted in matrigel. These artificial nerve grafts could be cultivated in vitro for one week. Histological analysis showed that the cells were vital and formed distinct columns along the Silk fibres. In conclusion, our results show that artificial nerve grafts can be constructed successfully from Spider Silk, acellularized veins and SC mixed with matrigel.