Robust composite silk fibers pulled out of silkworms directly fed with nanoparticles

Intrinsically reinforced silks obtained by incorporation of graphene quantum dots into silkworms

“…It should be noted that the control-silks in this study show a lower breaking strength (246.28 MPa) compared with the typical commercial silks (300-700 MPa) [7,27], the difference should be attributed to the variety of silkworms [27]. It was reported that the mechanical properties of silks were closely related to the rearing environment, spinning speed, degumming process, test-ing parameters, etc.…”

“…Traditional extrinsical functionalization immobilizes certain additives on the surface of silks [12][13][14][15], or re-spin silk fibers from regenerated silk fibroin solution with additives [16][17][18], during which period the structures of silks are easily destroyed due to tedious procedures, harsh condition and the use of toxic reagents. Intrinsical functionalizations including genetic alteration [19][20][21] of silkworms or in vivo uptake of specific diets by silkworms [22][23][24][25][26][27] can result in modified silks directly and are much greener. Compared with genetic alteration which needs complicated procedures, the recently developed in vivo uptake method is much easier.…”

“…Compared with genetic alteration which needs complicated procedures, the recently developed in vivo uptake method is much easier. Several groups have acquired functionalized silks via adding additives such as dyes [22,23], amino acids [24], bordeaux mixture [25] and nanomaterials [26][27][28][29][30][31] into the feed of silkworms, among which nanomaterials gain much attention owing to their unique mechanical, antibacterial and photoelectric properties, etc. Cai et al [26] demonstrated that silks with improved mechanical properties could be produced by adding TiO 2 nanoparticles into the feed of silkworms.…”

“…Cai et al [26] demonstrated that silks with improved mechanical properties could be produced by adding TiO 2 nanoparticles into the feed of silkworms. Our group [27] found that the mechanical properties of silks could be enhanced significantly by feeding silkworms with mulberry leaves sprayed with copper nanoparticles. Wang and coworkers [28] obtained pristine magnetic silks by feeding silkworms with mulberry leaves sprayed with nano Fe 3 O 4 powder.…”

Disruption of the Metal Ion Environment by EDTA for Silk Formation Affects the Mechanical Properties of Silkworm Silk

“…A number of researchers have reported that the mechanical properties of silk fiber can be modified by transgenic silkworm overexpression with the spider gene [3,4,5,6]. In addition, numerous studies have attempted to endow the silk fiber with special mechanical performance directly by feeding silkworms with inorganic nanoparticles such as single-walled carbon nanotubes, nanocarbon, TiO 2 nanoparticles, and graphene [7,8,9,10]. Especially, recent evidence suggests that metal ions, pH, and shear forces are involving in the conformational transition of silk proteins, which will affect the mechanical properties of silk fiber [11,12].…”