Bioinspired Silk Fiber Spinning System via Automated Track-Drawing

Abstract

Regenerated silk fibroin (SF) fiber is a multifaceted protein matrix suitable for engineering a wide variety of biological materials. Numerous artificial spinning systems have been developed to mimic the molecular structure and hierarchical properties found in native silks. Here, we show a bioinspired technique that can readily form nanofibers and induce both orientation and structure formation of crystalline β-sheet assemblies seen in natural silk. In this study, electrospun postdrawn SF nanofibers were fabricated using an automated track-drawing (TD) approach for the continuous production of highly aligned protein nanofibers. This one-step postdrawing process simulates the dominant pulling force seen in natural spinning. The mechanical performance of the postdrawn SF nanofibers with a draw ratio of 2 (DR2) via TD exhibited a 115% increase in Young's modulus and an 80% increase in ultimate tensile strength, compared with the undrawn SF fibers after water treatment. It was also determined that the intermolecular β-sheet content in DR2 nanofibers increased by 75%. This contribution led to higher glass-transition and degradation temperatures. These biomimetic fibers with structural hierarchy and mechanical properties may be used to build high-performance load-bearing and directionally propagating structures relevant in biomaterial and sustainable material applications.

Impact of physio-chemical spinning conditions on the mechanical properties of biomimetic spider silk fibers

“…Detailed quantification of the influence of post-spin stretching could provide useful information to maximize the strength 28,52 , as has been shown e.g. for a fiber made from regenerated silk fibroin that gained an increased strength of up to 80% with a 2-fold drawing ratio 45,54,55 . There are no reports of post-spin stretched NT2RepCT fibers, as all the fibers described thus far refer to asspun fibers (Supplementary Table 2).…”

Flexible and Biocompatible Silk Fiber-Based Composite Phase Change Material for Personal Thermal Management

“…The TGA curves are shown in Figure b, and the corresponding data are listed in Table S2. The mass loss of SF in the TGA curve (314–342.1 °C) can be assigned to the thermal decomposition of organic macromolecules (fibroin). , In the temperature region from 100 to 250 °C, the pure CA and the SF/CA composite PCM have a significant weight loss due to the decomposition of CA. The onset decomposition temperature of the SF/CA composite PCM is slightly lower than that of the pure CA, which may be due to the interaction between CA and the SF support material slightly reducing the thermal stability of CA.…”

Research Progress on Spider‐Inspired Tough Fibers†

“…By simulating the process of silk postdrawing and applying external high pressure that the silkworm itself could not withstand, Dave et al . [ 79 ] altered the internal chemical bond composition of proteins as well as the arrangement of their molecular chains and β‐sheet crystals, thus leading to the improvement of the molecular orientation and mechanical characteristics of electrostatic spinning nanofibers (Figure 12 a—d). Compared with unstretched regenerated silk fibroin protein, the mechanical properties got enhanced by 115%, the ultimate tensile strength increased by 80%, and the glass transition and degradation temperature also increased.…”