Properties of Biomimetic Artificial Spider Silk Fibers Tuned by PostSpin Bath Incubation

Efficient production of artificial spider silk fibers with properties that match its natural counterpart has still not been achieved. Recently, a biomimetic process for spinning recombinant spider silk proteins (spidroins) was presented, in which important molecular mechanisms involved in native spider silk spinning were recapitulated. However, drawbacks of these fibers included inferior mechanical properties and problems with low resistance to aqueous environments. In this work, we show that ≥5 h incubation of the fibers, in a collection bath of 500 mM NaAc and 200 mM NaCl, at pH 5 results in fibers that do not dissolve in water or phosphate buffered saline, which implies that the fibers can be used for applications that involve wet/humid conditions. Furthermore, incubation in the collection bath improved the strain at break and was associated with increased β-sheet content, but did not affect the fiber morphology. In summary, we present a simple way to improve artificial spider silk fiber strain at break and resistance to aqueous solvents.

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Hydrothermal Effect on Mechanical Properties of Nephila pilipes Spidroin

Polymers ◽

10.3390/polym12051013 ◽

2020 ◽

Vol 12 (5) ◽

pp. 1013 ◽

Cited By ~ 1

Author(s):

Hsuan-Chen Wu ◽

Aditi Pandey ◽

Liang-Yu Chang ◽

Chieh-Yun Hsu ◽

Thomas Chung-Kuang Yang ◽

...

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Spider Silk ◽

Post Treatment ◽

Molecular Structures ◽

Random Coil ◽

Silk Fibers ◽

Physical Strength ◽

Β Sheet ◽

Post Treatment Process

The superlative mechanical properties of spider silk and its conspicuous variations have instigated significant interest over the past few years. However, current attempts to synthetically spin spider silk fibers often yield an inferior physical performance, owing to the improper molecular interactions of silk proteins. Considering this, herein, a post-treatment process to reorganize molecular structures and improve the physical strength of spider silk is reported. The major ampullate dragline silk from Nephila pilipes with a high β-sheet content and an adequate tensile strength was utilized as the study material, while that from Cyrtophora moluccensis was regarded as a reference. Our results indicated that the hydrothermal post-treatment (50–70 °C) of natural spider silk could effectively induce the alternation of secondary structures (random coil to β-sheet) and increase the overall tensile strength of the silk. Such advantageous post-treatment strategy when applied to regenerated spider silk also leads to an increment in the strength by ~2.5–3.0 folds, recapitulating ~90% of the strength of native spider silk. Overall, this study provides a facile and effective post-spinning means for enhancing the molecular structures and mechanical properties of as-spun silk threads, both natural and regenerated.

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Self-assembled semi-crystallinity at parallel β -sheet nanocrystal interfaces in clustered MaSp1 (spider silk) proteins

Materials Science and Engineering C ◽

10.1016/j.msec.2015.08.038 ◽

2016 ◽

Vol 58 ◽

pp. 366-371 ◽

Cited By ~ 16

Author(s):

Erly Sintya ◽

Parvez Alam

Keyword(s):

Spider Silk ◽

Silk Proteins ◽

Self Assembled ◽

Β Sheet

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Scalable Spider Silk Inspired Materials with High Extensibility and Super Toughness

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.893.31 ◽

2021 ◽

Vol 893 ◽

pp. 31-35

Author(s):

Jin Lian Hu ◽

Yuan Zhang Jiang ◽

Lin Gu

Keyword(s):

Chemical Synthesis ◽

Spider Silk ◽

Helical Structure ◽

Silk Proteins ◽

Dragline Silk ◽

Spider Dragline Silk ◽

Argiope Trifasciata ◽

Chemical Synthesis Route ◽

Β Sheet ◽

Huge Challenge

Spiders silks have extraordinary strength and toughness simultaneously, thus has become dreamed materials by scientists and industries. Although there have been tremendous attempts to prepare fibers from genetically manufacture spider silk proteins, however, it has been still a huge challenge because of tedious procedure and high cost. Here, a facile spider-silk-mimicking strategy is reported for preparing highly scratchable polymers and supertough fibers from chemical synthesis route. Polymer films with high extensibility (>1200%) and supertough fibers (~387 MJ m-3) are achieved by introducing polypeptides with β-sheet and α-helical structure in polyureathane/urea polymers. Notabley,the toughness of the fiber is more than twice the reported value of a normal spider dragline silk, and comparable with the toughest spider silk, aciniform silk of Argiope trifasciata.

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Transgenic and Diet-Enhanced Silk Production for Reinforced Biomaterials: A Metamaterial Perspective

Annual Review of Biomedical Engineering ◽

10.1146/annurev-bioeng-082719-032747 ◽

2020 ◽

Vol 22 (1) ◽

pp. 79-102 ◽

Cited By ~ 1

Author(s):

Jung Woo Leem ◽

Malcolm J. Fraser ◽

Young L. Kim

Keyword(s):

Biomedical Applications ◽

Large Scale ◽

Spider Silk ◽

Biological Properties ◽

Fiber Spinning ◽

Silk Proteins ◽

Silk Fibers ◽

Production Methods ◽

Synthetic Materials ◽

Functional Additive

Silk fibers, which are protein-based biopolymers produced by spiders and silkworms, are fascinating biomaterials that have been extensively studied for numerous biomedical applications. Silk fibers often have remarkable physical and biological properties that typical synthetic materials do not exhibit. These attributes have prompted a wide variety of silk research, including genetic engineering, biotechnological synthesis, and bioinspired fiber spinning, to produce silk proteins on a large scale and to further enhance their properties. In this review, we describe the basic properties of spider silk and silkworm silk and the important production methods for silk proteins. We discuss recent advances in reinforced silk using silkworm transgenesis and functional additive diets with a focus on biomedical applications. We also explain that reinforced silk has an analogy with metamaterials such that user-designed atypical responses can be engineered beyond what naturally occurring materials offer. These insights into reinforced silk can guide better engineering of superior synthetic biomaterials and lead to discoveries of unexplored biological and medical applications of silk.

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Mechanical Properties of Spider Silk for Use As a Biomaterial: Molecular Dynamics Investigations

Volume 3: Advanced Materials: Design, Processing, Characterization, and Applications ◽

10.1115/imece2020-23951 ◽

2020 ◽

Author(s):

Atul Rawal ◽

Kristen L. Rhinehardt ◽

Ram V. Mohan

Keyword(s):

Mechanical Properties ◽

Molecular Dynamics ◽

Spider Silk ◽

Complete Separation ◽

Silk Protein ◽

Silk Proteins ◽

Silk Fibers ◽

Spider Silk Protein ◽

Β Chain ◽

Smd Simulations

Abstract Even though silkworm are the most dominant type of silk fibers used for commercial applications, spider silk has a definitive role in biomedical applications due to its biocompatibility and excellent mechanical properties as biomaterials. In recent years, recombinant production of the silk proteins at a larger scale has found new interest. Spider silk composites with a combination of a variety of other biomaterials have also been used to improve properties such as bio-compatibility, mechanical strength and controlled degradation. [1] A major constituent of spider silk fibers, are spidroin proteins. These are made up of repetitive segments flanked by conserved non-repetitive domains. The fiber proteins consist of a light chain and a heavy chain that are connected via a single disulfide bond. [2] Present paper employed steered molecular dynamics (SMD) as the principal method of investigating the mechanical properties of these nanoscale spider silk protein 3LR2, with a residual count of 134 amino acids. [3]. SMD simulations were performed by pulling on β-chain of the protein in the x-direction, while holding the other fixed. The focus of this paper is to investigate the mechanical properties of the nanoscale spider silk proteins with lengths of about 4.5nm in a folded state, leading to understanding of their feasibility in bio-printing of a composite spider silk biomaterial with a blend of various other biomaterials such as collagen. An in-depth insight into the fraying and tensile deformation and structural properties of the spider silk proteins are of innovative significance for a multitude of biomedical engineering applications. A calculated Gibbs free energy value of 18.59 kCal/mol via umbrella sampling corresponds with a complete separation of a single chain from a spider silk protein in case of fraying. Force needed for complete separation of the chain from the spider silk protein is analyzed, and discussed in this paper. It is found that the protein molecule undergoes a tensile stretch at strain rates of ≅ 11.65. An elastic modulus of 20.136 GPa, calculated via simple SMD simulations by subjecting the silk β-chain to a tensile stretch is also presented.

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Faculty Opinions recommendation of Spider silk fibers spun from soluble recombinant silk produced in mammalian cells.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1003596.39007 ◽

2002 ◽

Author(s):

Eaton E Lattman

Keyword(s):

Mammalian Cells ◽

Spider Silk ◽

Silk Fibers

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High‐toughness Spider Silk Fibers Spun from Soluble Recombinant Silk Produced in Mammalian Cells

Biopolymers Online ◽

10.1002/3527600035.bpol8005 ◽

2003 ◽

Author(s):

Costas N. Karatzas ◽

Nathalie Chretien ◽

François Duguay ◽

Annie Bellemare ◽

Jiang Feng Zhou ◽

...

Keyword(s):

Mammalian Cells ◽

Spider Silk ◽

Silk Fibers ◽

High Toughness

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Interfacial Crystallization and Supramolecular Self-Assembly of Spider Silk Inspired Protein at the Water-Air Interface

Materials ◽

10.3390/ma14154239 ◽

2021 ◽

Vol 14 (15) ◽

pp. 4239

Author(s):

Pezhman Mohammadi ◽

Fabian Zemke ◽

Wolfgang Wagermaier ◽

Markus B. Linder

Keyword(s):

Self Assembly ◽

Spider Silk ◽

Assembly Process ◽

Protein Solution ◽

Time Resolved ◽

Macromolecular Assembly ◽

X Ray Scattering ◽

Air Interface ◽

Fundamental Research ◽

Β Sheet

Macromolecular assembly into complex morphologies and architectural shapes is an area of fundamental research and technological innovation. In this work, we investigate the self-assembly process of recombinantly produced protein inspired by spider silk (spidroin). To elucidate the first steps of the assembly process, we examined highly concentrated and viscous pendant droplets of this protein in air. We show how the protein self-assembles and crystallizes at the water–air interface into a relatively thick and highly elastic skin. Using time-resolved in situ synchrotron X-ray scattering measurements during the drying process, we showed that the skin evolved to contain a high β-sheet amount over time. We also found that β-sheet formation strongly depended on protein concentration and relative humidity. These had a strong influence not only on the amount, but also on the ordering of these structures during the β-sheet formation process. We also showed how the skin around pendant droplets can serve as a reservoir for attaining liquid–liquid phase separation and coacervation from the dilute protein solution. Essentially, this study shows a new assembly route which could be optimized for the synthesis of new materials from a dilute protein solution and determine the properties of the final products.

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