Sericins

Serial basin test Sericin Sericin gum Senate [12174-53-7] Serinal... 

Commercial and Artificial Processing. Commercially, silkworm cocoons are extracted in hot soapy water to remove the sticky sericin protein. The remaining fibroin or stmctural sdk is reeled onto spools, yielding approximately 300—1200 m of usable thread per cocoon. These threads can be dyed or modified for textile appUcations. Production levels of sdk textiles in 1992 were 67,000 metric tons worldwide. The highest levels were in China, at 30,000 t, foUowed byJapan, at 17,000 t, and other Asian and Oceanian countries, at 14,000 t (24). Less than 3000 metric tons are produced annually in each of eastern Europe, western Europe, and Latin America almost no production exists in North America, the Middle East, or Africa. 1993 projections were for a continued worldwide increase in sdk textile production to 75,000 metric tons by 1997 and 90,000 metric tons by 2002 (24). 

Silk (qv) suture is made from the threads spun by the silkworm Bombjx mori. The fiber is composed principally of the protein fibroin and has a natural coating composed of sericin gum. The gum is usually removed before braiding the silk yams to make sutures in a range of sizes. Fine silk sutures may be made by simply twisting the gum-coated silk yams to produce the desired diameter. White silk is undyed. Silk is either dyed black with logwood extract or blue with D C Blue No. 9. The suture may be uncoated or coated either with high molecular weight polydimethylsiloxane or with wax. 

Bast, m. n. bast gum (of silk), sericin. Bastand., abbrev. (Barometerstand height of barometer. 

Serien-nummer, /. serial number, -schaltung, /. (Elec.) series connection, -schnitt, m. serial section, -spektrum, n. series spectrum, versuch, m. serial experiment or test. Serizin, n. sericin. 

Besides the previously mentioned collagen, a wide variety of natural polymers have been involved in the synthesis of bio-nanohybrid materials with potential application in bone repair and dental prostheses. For instance, some recent examples refer to bionanocomposites based on the combination of HAP with alginate [96,97], chitosan [98,99], bovine serum albumin (BSA) [100], sodium caseinate [101], hyaluronic acid [102], silk fibroin [103,104], silk sericin [105], or polylactic add (PLA) [106,107]. These examples illustrate the increasing interest in the subject of HAP-based biohybrid materials, which has led to almost 400 articles appeared in scientific journals in 2006 alone. 

Takeuchi et at. [60] reported that cloth made of raw silk (R-silk) fiber forms hydroxyapatite in 1.5SBF but cloth made of normal silk (N-silk) fiber does not. The surfaces of raw silk and normal silk fibers consist of sericin and fibroin, respectively. 

Silk fibers or monolayers of silk proteins have a number of potential biomedical applications. Biocompatibility tests have been carried out with scaffolds of fibers or solubilized silk proteins from the silkworm Bombyx mori (for review see Ref. [38]). Some biocompatibility problems have been reported, but this was probably due to contamination with residual sericin. More recent studies with well-defined silkworm silk fibers and films suggest that the core fibroin fibers show in vivo and in vivo biocompatibility that is comparable to other biomaterials, such as polyactic acid and collagen. Altmann et al. [39] showed that a silk-fiber matrix obtained from properly processed natural silkworm fibers is a suitable material for the attachment, expansion and differentiation of adult human progenitor bone marrow stromal cells. Also, the direct inflammatory potential of silkworm silk was studied using an in vitro system [40]. The authors claimed that their silk fibers were mostly immunologically inert in short and long term culture with murine macrophage cells. 

Lazo, N. D., and Downing, D. T. (1999). Crystalline regions of Bombyx mori silk fibroin may exhibit beta-turn and beta-helix conformations. Macromolecules 32, 4700-4705. Lee, K. H. (2004). Silk sericin retards the crystallization of silk fibroin. Macromol. Rapid Commun. 25, 1792-1796. 

Ser Senne HO — CHo — CH — COOH 1 NEUTRAL AMINO ACIDS—HYDROXY TYPE 1865 by Cramer (sericine) 5.7... 

When there is no indication of the loss undergone during the ungumming of the silk prior to weighting, such loss is usually taken at 25% for organsine and 20% for tram silk, so that with 75 or 80 parts of fibroin found there correspond 25 or 20 parts of sericin. 

If the loss on stripping is assumed to be 25 %, the amount of sericin corresponding with this amount of ungummed silk will be... 

Degwert, J. and Hoppe, U. 1996. Influence of the protein sericin on cellular interactions of immune relevant cells. Patfiimerie Kosmetik 77(2) 74, 76, 94-100. 

The B. mori silk fiber is made up of two kinds of protein. One is called sericin, a water-soluble protein responsible for the gum-like, sticky coating covering the fiber, and the other is referred to as fibroin, the core filament of silk. The inner part of silk fiber is composed of two monofilaments called brins (Figure la) (Poza et al., 2002 Shao and Vollrath, 2002). 

Figure 1 (a) the sericin (outer layer) and fibroin filaments of Bombyx mori silkworm (b) the... 

As the coating protein of cocoon silk, sericin is proposed for bioapplications, although it has been reported to cause hypersensitivity (Altman et al., 2003). It is suggested that sericin could suppress the development of colon tumor by reducing cell proliferation and nitric acid production (Zhaorigetu,... 

Terada, S., Sasaki, M., Yanagihara, K., and Yamada, H. "Preparation of silk protein sericin as mitogenic factor for better mammalian cell culture". ]. Biosci. Bioeng. 100(6), 667-671 (2005). 

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