An+Introduction+to+Spider+silk

//“Weight-for-weight stronger than steel, finer than human hair, more resilient than any synthetic fiber, and completely biodegradable, dragline silk is every inch the 21st century super-material.”// – Paula Gould [1]


 * Introduction**

Spider silk is one of the strongest natural fibres known, and it consists of an amino-acid based polymer. There are many different types of spider silk proteins which are produced to serve different functions from different glands in the spider. The strength of some spider silks, such as the dragline silk, is comparable to that of high-grade steel [2]. Spider silk is also of low density, ductile, and able to maintain these remarkable characteristics over a broad range of temperatures [3] and tensions [4] up to its breaking point. Thus, spider silk has potential applications in several areas including the development of bulletproof materials [5], in the treatment of open wounds and the delivery of drugs [6], and in the fabrication of textiles. Spiders are territorial creatures, thus they cannot be housed in high densities, and it is also very difficult to extract and process substantial amounts of spider silk from spiders. Because of this, researchers are developing methods to use other organisms such as E.coli [7], silkworms [8] and even goats [5] to produce larger quantities of spider silk via the cloning and insertion of these genes. The major challenges faced to date are replicating the complex conditions in a laboratory environment required to produce fibres that are comparable to natural spider silk. [4] The objectives of this project are to examine the chemical properties of spider silk, the methods of synthetic production and the current and potential applications.

**Content:**

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=Types of Spider Silk =

 The many unique characteristics of spider silk can be attributed from the different types of spider silk. The variety of the silk comes from the ability of the spider to produce different qualities of silks for different uses in their biological environment. The common silks produced in most arachnids include, major-ampullate silk, capture-spiral silk, tubuliform silk, aciniform silk and minor ammuplate silk. Though due to the extensive time it takes to produce mass amounts of this precious silk, recent science has developed alternative methods to harvesting artificial spider silk and other silk-like high performance materials... read more

=Properties of Spider Silk =

Dragline spider silk is a complex system of different proteins and types of crystallization. This complex system forms a substance with outstanding mechanical properties. Dragline spider silk is a phenomenal substance. Its numerous uses are just beginning to be discovered. Dragline silk is classified as such because it is the silk that is used along the radii and the outside of the spider`s web, as well as the dragline that the spider uses to lower itself. Despite how thin the material is, this type of silk is exceptionally strong and elastic. The reasons surrounding this strength and elasticity are attributed to the evolutionary purpose of the silk itself. The spider’s silk needs to be thin in order to increase efficiency and to conserve energy while spinning the web. Since the web is the main source of food for the spider, it needs to have the proper amount of elasticity so a flying insect does not simply bounce off... __read more __

=Production of Spider Silk =

Production of spider silk involves two important steps that need to be addressed in order to mass produce spider silk, these are: -**The harvesting of spider silk**: This can be done by either directly extracting it from spiders, or by using a genetically modified organism to produce the silk. Traditionally, in order to investigate the properties of spider silk or attempt to develop any applications for it, researchers had to collect the silk directly from spiders. In order to mass produce spider silk innovative methods have been developed; these involve cloning the genes responsible for producing the more common dragline silk threads... <span style="font-family: 'Times New Roman',Times,serif; font-size: 16px;">read more

<span style="font-family: 'Times New Roman',Times,serif; font-size: 16px;">-**The spinning of spider silk:** <span style="background-color: #ffffff; font-family: 'Times New Roman',Times,serif; font-size: 16px;">Spiders are able to spin their silk at near-ambient temperatures and pressures using water as a solvent. They are able to produce this by judiciously controlling the folding and crystallization of the main protein constituents, as well as adding auxiliary compounds to create a composite material of defined structure... <span style="font-family: 'Times New Roman',Times,serif; font-size: 16px;">read more

=<span style="font-family: 'Times New Roman',Times,serif; font-size: 16px;">Companies Focusing on the Development of Spider Silk Technology =

<span style="font-family: 'Times New Roman',Times,serif; font-size: 16px;">Several biotechnology firms, research groups and textile companies are currently investigating all properties of spider silk. The foundation of the research being conducted is based off the multitude of properties spider silk exhibits. Prior to 2002, the spider silk industry was based solely out of individual laboratories that were studying the useful material. The work done by these laboratories was painstaking and incredibly inefficient due to the method of extracting the spider silk. These laboratories used large quantities of spiders, extracting trace amounts of thread from each individual; with no ability or mean to extract mass amounts. In 2002, Nexia Biotechnologies, Canadian firm, developed a way to produce spider silk in larger quantity, more efficiently and voided the use of spiders all together (a trend that would continue for industrial purposes)... read more

=<span style="font-family: 'Times New Roman',Times,serif; font-size: 16px;">Applications of Spider Silk = <span style="font-family: 'Times New Roman',Times,serif; font-size: 16px;"> <span style="font-family: 'Times New Roman',Times,serif; font-size: 16px;">Owing to its versatile properties, spider silk has potential applications in the medical field, military industry, and in the manufacture of textiles and recreational tools... read more

=<span style="font-family: 'Times New Roman',Times,serif; font-size: 16px;">Spider Silk in the Media =

<span style="font-family: 'Times New Roman',Times,serif; font-size: 16px;">Click here to see recent updates

<span style="font-family: 'Times New Roman',Times,serif; font-size: 16px;">[1]Gould, P. 2002. Exploiting Spiders’ Silk. Materials today. 5(12): 42-47. <span style="font-family: 'Times New Roman',Times,serif; font-size: 16px;">[2] Griffiths JR, Salanitri VR. 1980. The strength of spider silk. Journal of Material Science 15: 491-496. <span style="font-family: 'Times New Roman',Times,serif; font-size: 16px;">[3] Yang Y, Chen X, Shao Z, Zhou P, Porter D, Knight DP, Vollrath F. 2005. The toughness of spider silk at high and low temperatures. Advanced Materials 17 (1): 84-88. <span style="font-family: 'Times New Roman',Times,serif; font-size: 16px;">[4] Elices M, Guinea GV, Plaza GR, Karatzas C, Reikel C, Agullo-Rueda F, Daza R, Perez-Rigueiro J. 2011. Bioinspired fibers follow the track of natural spider silk. Macromolecules 44: 1166-1176. <span style="font-family: 'Times New Roman',Times,serif; font-size: 16px;">[5] Lazaris A, Arcidiacono S, Huang Y, Zhou JF, Duguay F, Chretien N, Welsh EA, Soares JW, Karatzas CN. 2002. Spider silk fibers spun from soluble recombinant silk produced in mammalian cells. Science 295 (5554): 472-476. <span style="font-family: 'Times New Roman',Times,serif; font-size: 16px;">[6] Kluge JA, Rabotyagova O, Leisk GG, Kaplan DL. 2008. Spider silks and their applications. Trends in Biotechnology 26(5): 244-251. <span style="font-family: 'Times New Roman',Times,serif; font-size: 16px;">[7] Xia XX, Qiana ZG, Kib CS, Parkb YH, Kaplanc DL, Lee SY. 2010. Native-sized recombinant spider silk protein produced in metabolically engineered Escherichia coli results in a strong fiber. PNAS 107 (32): 14059–14063. <span style="font-family: 'Times New Roman',Times,serif; font-size: 16px;">[8] Teuléa F, Miaob YG, Sohnc BH, Kimc YS, Hulla JJ, Fraser MJ, Lewisa RV, Jarvisa DL. 2011. Silkworms transformed with chimeric silkworm/spider silk genes spin composite silk fibers with improved mechanical properties. PNAS. doi: 10.1073/pnas.1109420109. Accessed Feb 13, 2012.