Fibroin polymer

Yuan, Q., Yao, J., Huang, L., Chen, X., Shao, Z., 2010. Correlation between structural and dynamic mechanical transitions of regenerated silk fibroin. Polymer 51, 6278-6283. 

Sionkowska, A., Planecka, A. The influence of UV radiation on silk fibroin. Polym. Degrad. Stab. 96, 523-528 (2011)... 

Asakura, Yao, J., Yang, M., Zhu, Z., and Hirose, H., Stracture of the Spinning Apparatus of a Wild Silkworm Sarnia Cynthia Ricini and Molecular Dynamics Calculation on the Stmctural Change of the Silk Fibroin , Polymer, 48, 2064-2070,2007. 

Several examples have been described in which a chiral natural polymer, such as silk fibroin or chitosan, act as chiral ligand and support at the same time. In such cases, the chiral ligand (the monomer or monomers coordinating... 

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. 

Inoue, S. I., Magoshi, J., Tanaka, T., Magoshi, Y., and Becker, M. (2000b). Atomic force microscopy Bombyx mori silk fibroin molecules and their higher order structure. /. Polym. Sci. BPolym. Phys. 38, 1436-1439. 

Tsukada, M., Freddi, G., Gotoh, Y., and Kasai, N. (1994). Physical and chemical-properties of tussah silk fibroin films. / Polym. Sri. B Polym. Phys. 32, 1407-1412. 

The beta arrangement, or pleated sheet conformation (see Figure 14.2), is predominant when small pendant groups are present in the chain, as in silk fibroin. The silk fibroins, which are spun by various species of silkworms, are monofilament polypeptides with extensive secondary interchain bonding. The crystalline portion of the fibroin is a polymer of a hexapeptide. The... 

The first successful experiments were reported by Schwab [16] Cu, Ni and Pt on quartz HI were used to dehydrogenate racemic 2-butanol 23. At low conversions, a measurable optical rotation of the reaction solution indicated that one enantiomer of 23 had reacted preferentially (eeright-handed quartz gave the opposite optical rotation it was deduced that the chiral arrangement of the crystal was indeed responsible for this kinetic resolution (for a review see [8]). Later, natural fibres like silk fibroin H5 (Akabori [21]), polysaccharides H8 (Balandin [23]) and cellulose H12 (Harada [29]) were employed as chiral carriers or as protective polymer for several metals. With the exception of Pd/silk fibroin HS, where ee s up to 66% were reported, the optical yields observed for catalysts from natural or synthetic (H8, Hll. H13) chiral supports were very low and it was later found that the results observed with HS were not reproducible [4],... 

The attractive properties of silk fibers as a natural, sustainable product have inspired researchers to look for options to fabricate such fibers without the use of worms or spiders. Furthermore, these natural polymers, silk proteins (both fibroin and spidroin), allow for adjustable mechanical properties, thermal resistance (Drummy et al., 2005 Motta et al., 2002), as well as biomedical compatibility (Vepari and Kaplan, 2007). 

In order to improve the properties and the spinnability, fibroin sometimes has been electrospun together with other natural or synthetic polymers (Jin et al., 2002 Park et al., 2004, 2006 Wang et al., 2004, 2006). For instance, Jin et al. (2002) developed an aqueous process for silk electrospinning in combination with PEO. More recently, Cao (2008) used PVA/Silk Fibroin (SF), Gelatin/SF, and Hydroxyapatite (HAP)/SF to produce double-layered (core-shell) nanofibers (mats) by coelectrospinning. 

To extend the application area of silk proteins-based materials, blending the fibroin with other natural macromolecules and synthetic polymers, or even manufacturing composites with silk fibers are a few of the possible strategies. 

Arai, T., Freddi, G., Innocenti, R., and Tsukada, M. "Biodegradation of Bombyx mori silk fibroin fibers and films".. Appl. Polym. Sci. 91(4), 2383-2390 (2004). 

Chen, C., Cao, C.B., Ma, X.L., Tang, Y., and Zhu, H.S. "Preparation of non-woven mats from all-aqueous silk fibroin solution with electrospinning method". Polymer 47(18), 6322-6327 (2006a). 

Freddi, G., Tsukada, M., and Beretta, S. "Structure and physical properties of silk fibroin polyacrylamide blend films". ]. Appl. Polym. Sci. 71(10), 1563-1571 (1999). 

Hu, K., Lv, Q., Cui, F.Z., Feng, Q.L., Kong, X.D., Wang, H.L., Huang, L.Y., and Li, T. "Biocompatible fibroin blended films with recombinant human-like collagen for hepatic tissue engineering". J. Bioact. Compat. Polym. 21(1), 23-37 (2006a). 

Kino, R., Ikoma, T., Monkawa, A., Yunoki, S., Munekata, M., Tanaka, J., and Asakura, T. "Deposition of bone-like apatite on modified silk fibroin films from simulated body fluid". J. Appl. Polym. Sci. 99(5), 2822-2830 (2006). 

Matsumoto, K., Uejima, H., Iwasaki, T., Sano, Y., and Sumino, H. "Studies on regenerated protein fibers 3. Production of regenerated silk fibroin fiber by the self-dialyzing wet spinning method". J. Appl. Polym. Sci. 60(4), 503-511 (1996). 

Motta, A., Migliaresi, C., Faccioni, F., Torricelli, P., Fini, M., and Giardino, R. "Fibroin hydrogels for biomedical applications Preparation, characterization and in vitro cell culture studies". ]. Biomat. Sci. Polym. Ed. 15(7), 851-864 (2004). 

Shulha, H., Foo, C.W.P., Kaplan, D.L., and Tsukruk, V.V. "Unfolding the multi-length scale domain structure of silk fibroin protein"Polymer 47(16), 5821-5830 (2006). 

Wang, H., Shao, H.L., and Hu, X.C. "Structure of silk fibroin fibers made by an electrospinning process from a silk fibroin aqueous solution". J. Appl. Polym. Sci. 101(2), 961-968 (2006). 

Internal Structure of Silk and Linen. Triangular-shaped silk filaments (called brins and composed of the protein fibroin) are embedded in a second protein (sericin) to form the bave unit. Microscopic examination of fabrics woven with the silk bave unit and subsequently cleaned of sericin reveals paired brin filaments. Fibroin contains 16 amino acids, and more than 80 of the polymer is composed of glycine, alanine, and serine only (6). Their small side groups allow chains of these amino acids to pack together closely to form the crystalline portions of the fiber. The bulkier amino acids, such as tyrosine, disrupt crystal order and produce the amorphous areas of the internal structure of the fiber. 

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