Design, Fabrication, and Function of Silk‐Based Nanomaterials

Abstract

Animal silks, consisting of pure protein components, offer an extraordinary combination of strength, elongation, and toughness, exceeding most engineered materials. The secret to this success is their unique nanoarchitectures formed through the hierarchical self-assembly of silk proteins. This natural process contrasts the production of artificial silk materials, which usually are directly constructed as bulk structures from silk fibroin molecular. A variety of fabrication strategies to control nanostructures of silks or to create functional materials from silk nanoscale building blocks have been developed in the recent years. These emerging fabrication strategies offer an opportunity to tailor the structure of SF at the nanoscale and provide a promising route to produce structurally and functionally optimized silk nanomaterials. Herein, the critical roles of silk nanoarchitectures on property and function of natural silk fibers is reviewed and the strategies of utilization of these silk nanobuilding blocks is outlined. Further, the state of the art techniques to create silk nanoarchitectures and to generate silk-based nanocomponents is summarized. An effective approach to constructing sophisticated silk functional nanocomposites with promising applications in regenerative medicine, drug delivery, as well as optical and electronic device designs is provided.Further, such insights suggest templates to consider for other materials systems.

Ultrastrong and Highly Sensitive Fiber Microactuators Constructed by Force‐Reeled Silks

“…These characteristics are almost 1.6 times higher than that of the CSF with strength and modulus of 359 ± 83 MPa and 7 ± 2 GPa, respectively. Furthermore, the FRSF is tougher than most of the natural and synthetic materials and is comparable with N. clavipes spider silk with the strain of 31 ± 6% and the toughness of 131 ± 77 MJ m −3 . The trade‐off of the strength, modulus, and the toughness in the FRSF is better than those for most of the synthetic fibers (Figure d).…”

“…First, the primary structure of the A. pernyi silk is similar to that of the spider silk . In other words, both silk proteins consist of the highly repetitive poly (alanine) and glycine‐rich domains . Second, A. pernyi silks are widely available, while low‐cost and sustainable .…”

“…2020, 7,1902743 FRSF is tougher than most of the natural and synthetic mate rials and is comparable with N. clavipes spider silk with the strain of 31 ± 6% and the toughness of 131 ± 77 MJ m −3 . [18,24,25] The tradeoff of the strength, modulus, and the toughness in the FRSF is better than those for most of the synthetic fibers ( Figure 2d). For example, although the strength and the Young's modulus of Kevlar fiber approach to 3.6 and 130 GPa, the corre sponding strain to failure and the toughness are only 2.7% and 50 MJ m −3 .…”

“…[16,17] In other words, both silk proteins consist of the highly repetitive poly (alanine) and glycinerich domains. [18] Second, A. pernyi silks are widely available, while lowcost and sustainable. [19,20] More spe cifically, the global annual production of A. pernyi cocoons is up to 60 000 tons, [9] and no specific feeding environment is required for A. pernyi silkworms.…”

Revealing the Influence of the Degumming Process in the Properties of Silk Fibroin Nanoparticles

“…In general, a hot aqueous medium is used as extracting medium, preferably alkaline, in which SS is soluble and thus is separated from SF fibers, which remain essentially insoluble under these conditions. Several degumming methods have been reviewed recently showing the effect of this critical processing step on the structure and properties of SF for multiple applications [15][16][17][18][19][20][21][22][23][24]. Among the different methods, the use of an autoclave in different configurations is frequently mentioned: in an aqueous solution subjected to 121 °C for 20 minutes [15] or using water vapor generated in the autoclave [17].…”