Home About us Contact
|
Home About us Contact | ||
|
|
||
Spider Silk (spider + silk)
Selected AbstractsToughness of Spider Silk at High and Low Temperatures,ADVANCED MATERIALS, Issue 1 2005Y. Yang The toughness of the major ampullate silk of spiders is shown to increase at low temperatures, unlike synthetic fibers. This temperature dependence of the mechanical properties of spider silk, together with other remarkable properties, demonstrates the potential usefulness of such a super-fiber in harsh environments. The Figure shows a single fiber of Nephila edulis spider silk fractured in liquid nitrogen. [source] Similarities in the Structural Organization of Major and Minor Ampullate Spider SilkMACROMOLECULAR RAPID COMMUNICATIONS, Issue 9-10 2009Periklis Papadopoulos Abstract Minor and major ampullate spider silks are studied under varying mechanical stress by static and time-resolved FT-IR spectroscopy. This enables one to trace the external mechanical excitation on a microscopic level and to determine for the different moieties the time dependence of the molecular order parameters and corresponding band shifts. It is concluded that the hierarchical nanostructure of both types of silk is similar, being composed of highly oriented nanocrystals, which are interconnected by amorphous chains that obey the worm-like chain model and have a Gaussian distribution of pre-strain. By that it is possible to describe the mechanical properties of both silks by two adjustable parameters only, the center and width of the distribution. For major ampullate silk, the observed variability is small in pronounced contrast to the findings for minor ampullate. [source] Skeletal tissue engineering using silk biomaterialsJOURNAL OF TISSUE ENGINEERING AND REGENERATIVE MEDICINE, Issue 2-3 2008Ana C. MacIntosh Abstract Silks have been proposed as potential scaffold materials for tissue engineering, mainly because of their physical properties. They are stable at physiological temperatures, flexible and resist tensile and compressive forces. Bombyx mori (silkworm) cocoon silk has been used as a suture material for over a century, and has proved to be biocompatible once the immunogenic sericin coating is removed. Spider silks have a similar structure to silkworm silk but do not have a sericin coating. This paper provides a general overview on the use of silk protein in biomaterials, with a focus on skeletal tissue engineering. Copyright © 2008 John Wiley & Sons, Ltd. [source] Toughness of Spider Silk at High and Low Temperatures,ADVANCED MATERIALS, Issue 1 2005Y. Yang The toughness of the major ampullate silk of spiders is shown to increase at low temperatures, unlike synthetic fibers. This temperature dependence of the mechanical properties of spider silk, together with other remarkable properties, demonstrates the potential usefulness of such a super-fiber in harsh environments. The Figure shows a single fiber of Nephila edulis spider silk fractured in liquid nitrogen. [source] A simple method for orienting silk and other flexible fibres in transmission electron microscopy specimensJOURNAL OF MICROSCOPY, Issue 3 2001J. E. Trancik When microstructures are characterized by transmission electron microscopy (TEM), the interpretation of results is facilitated if the material can be sectioned in defined orientations. In the case of fibres, it is especially useful if transverse and longitudinal sections can be obtained reliably. Here we describe a procedure for orienting spider silk and other flexible fibres for TEM investigation. Prior to embedding in epoxy resin, the silk is wound around a notched support made from polyester film. No glue is required. After the silk and its supporting film have been embedded and the resin has been cured the film can be peeled away to reveal nearly perfectly orientated silk threads. Both transverse and longitudinal sections can then be cut with a microtome. The method can be extended to obtain sections at any intermediate orientation. [source] The Weaver Wasp: Spinning Fungus into a NestBIOTROPICA, Issue 4 2010Mario X. Ruiz-González ABSTRACT Wasp nests range from simple to complex structures made of paper or mud. Here, we show that a Neotropical wasp of the genus Nitela builds its nest entirely by weaving endophytic fungal hyphae and spider silk harvested from the leaves growing in the understory of the rain forest in French Guiana. [source] Spider silk fibres in artificial nerve constructs promote peripheral nerve regenerationCELL PROLIFERATION, Issue 3 2008C. Allmeling 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. [source] Production and processing of spider silk proteinsJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 16 2009John G. Hardy Abstract Natural spider silk fibers have impressive mechanical properties (outperforming many man-made fibers) and are, moreover, biocompatible, biodegradable, and produced under benign conditions (using water as a solvent at ambient temperature). The problems associated with harvesting natural spider silks inspired us to devise a method to produce spider silk-like proteins biotechnologically (the first subject tackled in this highlight); we subsequently discuss their processing into various materials morphologies, and some potential technical and biomedical applications. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3957,3963, 2009 [source] Similarities in the Structural Organization of Major and Minor Ampullate Spider SilkMACROMOLECULAR RAPID COMMUNICATIONS, Issue 9-10 2009Periklis Papadopoulos Abstract Minor and major ampullate spider silks are studied under varying mechanical stress by static and time-resolved FT-IR spectroscopy. This enables one to trace the external mechanical excitation on a microscopic level and to determine for the different moieties the time dependence of the molecular order parameters and corresponding band shifts. It is concluded that the hierarchical nanostructure of both types of silk is similar, being composed of highly oriented nanocrystals, which are interconnected by amorphous chains that obey the worm-like chain model and have a Gaussian distribution of pre-strain. By that it is possible to describe the mechanical properties of both silks by two adjustable parameters only, the center and width of the distribution. For major ampullate silk, the observed variability is small in pronounced contrast to the findings for minor ampullate. [source] | ||||||||||||||||