2. 2
ꙮ Mechanical Properties: Silk vs Other polymers
ꙮ Effect of internal structure
ꙮ Effect of moisture content
ꙮ Effect of temperature
ꙮ In vitro Degradation
ꙮ Immunological Responses
6. 6
ꙮ β-sheet crystallites & amorphous matrix
ꙮ Parallel vs. antiparallel β-sheet crystallites
Structures, mechanical properties and applications of silk fibroin materials, Leng-Duei Koh, Progress in Polymer Science 46 (2015) 86–110
7. 7
ꙮ Intermolecular vs. intramolecular β-sheet crystallites
ꙮ Size of β-sheet crystallites
Structures, mechanical properties and applications of silk fibroin materials, Leng-Duei Koh et al., Progress in Polymer Science 46 (2015) 86–110
8. 8
ꙮ Effect of water
content on the
properties of silk
(Bombyx mori)
Influence of Water Content on the β-Sheet Formation, Thermal Stability, Water Removal, and Mechanical Properties of Silk Materials, Kenjiro Yazawa,
Biomacromolecules 17 (2016) 1057−1066
9. 9
(a) Weight change in silk (b) Derivative plot of (a)
Influence of Water Content on the β-Sheet Formation, Thermal Stability, Water Removal, and Mechanical Properties of Silk Materials, Kenjiro Yazawa,
Biomacromolecules 17 (2016) 1057−1066
10. 10
ꙮ Silk, as a biomaterial, is defined by the United States Pharmacopeia(USP)
as non-degradable.
ꙮ It degrades in around a year.
ꙮ In vitro degradation of silk fibroin was studied by Rebecca Horan with
phosphate-buffered saline (PBS) & Protease XIV
11. 11
SEM images of silk fibers incubated in PBS for (a) 1 day, (b) 21 days and (c) 42 days, or in 1.0 mg/ml protease solution for
(d) 1 day, (e)21 days and (f) 42 days.
In vitro degradation of silk fibroin, Rebecca L. Horan et al., Biomaterials 26 (2005) 3385–3393
12. 12
Mass of silk matrix as a function of time in PBS or 1.0 mg/ml protease.
13. 13
ꙮ strong immune reactions took place only when virgin silk was used.
ꙮ Degummed silk sutures were relatively inert.
ꙮ fibroin-coated polyester sutures have demonstrated that regenerated
silk fibroin does not induce any significant thrombogenicity.
14. 14
[1] L. D. Koh et al., “Structures, mechanical properties and applications of silk
fibroin materials,” Prog. Polym. Sci., vol. 46, pp. 86–110, 2015.
[2] K. Yazawa, K. Ishida, H. Masunaga, T. Hikima, and K. Numata, “Influence
of Water Content on the β-Sheet Formation, Thermal Stability, Water
Removal, and Mechanical Properties of Silk Materials,”
Biomacromolecules, vol. 17, no. 3, pp. 1057–1066, 2016.
[3] M. Santin, A. Motta, G. Freddi, and M. Cannas, “In vitro evaluation of the
inflammatory potential of the silk fibroin,” J. Biomed. Mater. Res., vol. 46,
no. 3, pp. 382–389, 1999.
