Structural and characterization studies of insoluble thai bombyx mori silk fibroin films


  • Noor Izyan Syazana Mohd Yusoff Universiti Teknologi Malaysia
  • Mat Uzir Wahit Universiti Teknologi Malaysia
  • Juhana Jaafar Universiti Teknologi Malaysia
  • Tuck-Whye Wong Universiti Teknologi Malaysia



Silk fibroin films, post treatment, induce β sheet, insoluble films


Bombyx Mori fiber consists of two major proteins which are fibroin and sericin. The silk fibroin (SF) is the core structural protein of silk fiber. SF protein structures comprise of primary and secondary structures; where the primary structure contains series of amino acid and secondary structure with Silk I refers to the water-soluble and Silk II, high β sheet extent which is insoluble. This study was conducted to compare the structural and characterization of insoluble Thai Bombyx Mori SF with different types of post-treatement.  Thai silk cocoons, which were degummed and dissolved in 9.3 M LiBr solution at 60 °C. The obtained SF solutions were dialyzed and purified. SF films were prepared by solution casting and immersing in methanol and ethanol, followed by water annealing in water saturated  vacuum. Post-treatment was purposely done to regenerate and induce of the β sheet structure to enhance the insolubilities and the stabilities properties of the SF films. The SF films structural conformation, characterization and thermal stability were characterized. Attenuated total reflectance-Fourier transformed infrared spectroscopy (ATR-FTIR) showed that SF films were presented in a more stable form after ethanol post treatment, which also supporting by X-ray diffraction (XRD) analysis which indicated the tendency to higher structural organization.  Thermal analysis resutls showed that SF was thermally stable and improved after post treatment.  The contact angle of post treated SF increased the hydrophobicity of the  films. The  thai SF films could be the promising candidate for applications in tissue regeneration, optical devices, and flexible electronic displays with the possibility  to control the SF structure and properties.

Author Biographies

Noor Izyan Syazana Mohd Yusoff, Universiti Teknologi Malaysia

Faculty of Chemical and Energy Engineering

Mat Uzir Wahit, Universiti Teknologi Malaysia

Faculty of Chemical and Energy Engineering

Juhana Jaafar, Universiti Teknologi Malaysia

Advanced Membrane Technology Research Centre (AMTEC)

Tuck-Whye Wong, Universiti Teknologi Malaysia

Faculty of Bioscience and Biomedical Engineering


Abdel-Fattah, W. I., Atwa, N., Ali, G. W. (2015). Influence of the protocol of fibroin extraction on the antibiotic activities of the constructed composites. Progress in Biomaterials, 4(2), 77-88.

Asakura, T., Kuzuhara, A., Tabeta, R., Saito, H. (1985). Conformational characterization of Bombyx mori silk fibroin in the solid state by high-frequency carbon-13 cross polarization-magic angle spinning NMR, x-ray diffraction, and infrared spectroscopy. Macromolecules, 18(10), 1841-1845.

Asha, S., Sangappa, Y., Ganesh, S. (2015). Tuning the refractive index and optical band gap of silk fibroin films by electron irradiation. Journal of Spectroscopy, 7.

Autran, P., Xavier, C., Dulce, G., Eduardo, L. (2010). Follow up of a model used for extraction fibroin by UV–VIS, XRD, FTIR and SEM/EDS. In: Congress of artificial organs and biomaterials.

Aznar-Cervantes, S., Martínez, J. G., Bernabeu-Esclapez, A., Lozano-Pérez, A. A., Meseguer-Olmo, L., Otero, T. F., et al. (2016). Fabrication of electrospun silk fibroin scaffolds coated with graphene oxide and reduced graphene for applications in biomedicine. Bioelectrochemistry, 108, 36-45.

Chankow, S., Luemunkong, S., Kanokpanont, S. (2016, 7-9 Dec. 2016). Conformational transitions of thai silk fibroin secondary structures. Paper presented at the 2016 9th Biomedical Engineering International Conference (BMEiCON), 1-5.

Cho, H. J., Ki, C. S., Oh, H., Lee, K. H., Um, I. C. (2012). Molecular weight distribution and solution properties of silk fibroins with different dissolution conditions. International Journal of Biological Macromolecules, 51(3), 336-341.

Hu, Y., Zhang, Q., You, R., Wang, L., Li, M. (2012). The relationship between secondary structure and biodegradation behavior of silk fibroin scaffolds. Advances in Materials Science and Engineering, 2012, 5.

Huang, X., Fan, S., Altayp, A. I. M., Zhang, Y., Shao, H., Hu, X., et al. (2014). Tunable structures and properties of electrospun regenerated silk fibroin mats annealed in water vapor at different times and temperatures. Journal of Nanomaterials, 2014, 7.

Hu, X., Kaplan, D., and Cebe, P. (2006). Determining beta-sheet crystallinity in fibrous proteins by thermal analysis and infrared spectroscopy. Macromolecules, 39(18), 6161-6170.

Jaramillo-Quiceno, N., Álvarez-López, C., Restrepo-Osorio, A. (2017). Structural and thermal properties of silk fibroin films obtained from cocoon and waste silk fibers as raw materials. Procedia Engineering, 200(Supplement C), 384-388.

Jin, H.-J., Park, J., Valluzzi, R., Cebe, P., Kaplan, D. L. (2004). Biomaterial films of bombyx mori silk fibroin with poly(ethylene oxide). Biomacromolecules, 5(3), 711-717.

Jin, H. J., Park, J., Karageorgiou, V., Kim, U. J., Valluzzi, R., Cebe, P., et al. (2005). Water‐stable silk films with reduced β‐sheet content. Advanced Functional Materials, 15(8), 1241-1247.

Lawrence, B. D., Omenetto, F., Chui, K., Kaplan, D. L. (2008). Processing methods to control silk fibroin film biomaterial features. Journal of Materials Science, 43(21), 6967.

Lawrence, B. D., Wharram, S., Kluge, J. A., Leisk, G. G., Omenetto, F. G., Rosenblatt, M. I., et al. (2010). Effect of hydration on silk film material properties. Macromolecular Bioscience, 10(4), 393-403.

Lee, M. C., Kim, D.-K., Lee, O. J., Kim, J.-H., Ju, H. W., Lee, J. M., et al. (2016). Fabrication of silk fibroin film using centrifugal casting technique for corneal tissue engineering. Journal of Biomedical Materials Research Part B: Applied Biomaterials, 104(3), 508-514.

Lee, X., Wahit, M. U., Adrus, N. (2016). Biodegradable and temperature-responsive thermoset polyesters with renewable monomers. Journal of Applied Polymer Science, 133(40), 1-9.

Li, M., Lu, S., Wu, Z., Tan, K., Minoura, N., Kuga, S. (2002). Structure and properties of silk fibroin–poly(vinyl alcohol) gel. International Journal of Biological Macromolecules, 30(2), 89-94.

Liu, M., Zhang, Y., Wu, C., Xiong, S., Zhou, C. (2012). Chitosan/halloysite nanotubes bionanocomposites: Structure, mechanical properties and biocompatibility. International Journal of Biological Macromolecules, 51(4), 566-575.

Lu, Q., Hu, X., Wang, X., Kluge, J. A., Lu, S., Cebe, P., et al. (2010). Water-insoluble silk films with silk I structure. Acta biomaterialia, 6(4), 1380-1387.

Nogueira, G. M., Rodas, A. C. D., Leite, C. A. P., Giles, C., Higa, O. Z., Polakiewicz, B., et al. (2010). Preparation and characterization of ethanol-treated silk fibroin dense membranes for biomaterials application using waste silk fibers as raw material. Bioresource Technology, 101(21), 8446-8451.

Putthanarat, S., Zarkoob, S., Magoshi, J., Chen, J. A., Eby, R. K., Stone, M., et al. (2002). Effect of processing temperature on the morphology of silk membranes. Polymer, 43(12), 3405-3413.

Sashina, E. S., Bochek, A. M., Novoselov, N. P., Kirichenko, D. A. (2006). Structure and solubility of natural silk fibroin. Russian Journal of Applied Chemistry, 79(6), 869-876.

Seib, F. P., Maitz, M. F., Hu, X., Werner, C., Kaplan, D. L. (2012). Impact of processing parameters on the haemocompatibility of Bombyx mori silk films. Biomaterials, 33(4), 1017-1023.

Silva, M. F., de Moraes, M. A., Nogueira, G. M., Rodas, A. C. D., Higa, O. Z., Beppu, M. M. (2013). Glycerin and ethanol as additives on silk fibroin films: Insoluble and malleable films. Journal of Applied Polymer Science, 128(1), 115-122.

Tsukada, M., Gotoh, Y., Nagura, M., Minoura, N., Kasai, N., Freddi, G. (1994). Structural changes of silk fibroin membranes induced by immersion in methanol aqueous solutions. Journal of Polymer Science Part B: Polymer Physics, 32(5), 961-968.

Um, I. C., Kweon, H., Park, Y. H., Hudson, S. (2001). Structural characteristics and properties of the regenerated silk fibroin prepared from formic acid. International Journal of Biological Macromolecules, 29(2), 91-97.

Wang, L., Lu, C., Zhang, B., Zhao, B., Wu, F., Guan, S. (2014). Fabrication and characterization of flexible silk fibroin films reinforced with graphene oxide for biomedical applications. RSC Advances, 4(76), 40312-40320.

Yoon, H., Kim, E. Y., Kim, H., Park, C. H., Joo, C.-K., Khang, G. (2014). Fabrication of transparent silk fibroin film for the regeneration of corneal endothelial cells; preliminary study. Macromolecular Research, 22(3), 297-303.

Zhang, C., Song, D., Lu, Q., Hu, X., Kaplan, D. L., Zhu, H. (2012). Flexibility regeneration of silk fibroin in vitro. Biomacromolecules, 13(7), 2148-2153.