Multiscale Modeling of Silk and Silk‐Based Biomaterials—A Review

Abstract

Silk embodies outstanding material properties and biologically relevant functions achieved through a delicate hierarchical structure. It can be used to create high‐performance, multifunctional, and biocompatible materials through mild processes and careful rational material designs. To achieve this goal, computational modeling has proven to be a powerful platform to unravel the causes of the excellent mechanical properties of silk, to predict the properties of the biomaterials derived thereof, and to assist in devising new manufacturing strategies. Fine‐scale modeling has been done mainly through all‐atom and coarse‐grained molecular dynamics simulations, which offer a bottom‐up description of silk. In this work, a selection of relevant contributions of computational modeling is reviewed to understand the properties of natural silk, and to the design of silk‐based materials, especially combined with experimental methods. Future research directions are also pointed out, including approaches such as 3D printing and machine learning, that may enable a high throughput design and manufacturing of silk‐based biomaterials.

Revealing Spider Silk's 3D Nanostructure Through Low Temperature Plasma Etching and Advanced Low-Voltage SEM

“…This is essential to build a quantitative picture of nano-and microstructure distribution, especially considering that spider silk modeling approaches have yet to incorporate our knowledge of these multi-scale structures (Yarger et al, 2018). The various approaches taken to date in the mechanistic modeling of spider silk have been summed up in a recent review (López Barreiro et al, 2018). Various modeling approaches have had some success in reproducing spider silk's mechanical behavior but the incorporation of multiscale structures and their interactions into mechanistic models is yet to be realized in part due to the practical difficulty of liking atomistic approaches to micron scale models.…”

“…Currently, mechanical models do not consider this radial structure present in the most extensively studied Nephila dragline silk, which is at odds with the widespread agreement that multiscale organization is integral to the fiber's characteristic tensile response (Nova et al, 2010;Giesa et al, 2011;Skelton and Nagase, 2012;López Barreiro et al, 2018;Yarger et al, 2018). A better dataset concerning the 3D mechanical properties and spatial distribution of different structural units within the silk will allow for better multi-scale mechanical models and will be important in successfully designing spider-silk mimicking fibers and polymers with tailored properties (Koeppel and Holland, 2017).…”

Hydrothermal Effect on Mechanical Properties of Nephila pilipes Spidroin

“…Spiders have evolved to produce unique/specialized silk proteins and build orb webs (comprised of silk threads) to account for various functional properties and applications [26]. Each of those silk proteins possess diverse material and biological properties that are tailored for specific applications [27][28][29]. In this research, we primarily compared the silk properties between two common spider species, N. pilipes and C. moluccensis, allowing us to screen the ideal silk material in the subsequent experiments of this research.…”

Tensegrity Modelling and the High Toughness of Spider Dragline Silk

“…Whilst there have been several concerted modelling efforts to relate silk's structures to its mechanical properties [3][4][5][6][7][8]18,19], accounting for the precise contributions of each of these structural elements on a fibre's mechanical response has been inconclusive. Consider, e.g., the role played by the interfaces between the fibrils, which some studies define as mechanically weak and responsible for easy slippage of adjacent fibrils [6], while other studies observe the presence of heterogeneous protrusions along such surfaces determining a non-slip kinematics and energy dissipation due to interlocking effects [20].…”

“…Consider, e.g., the role played by the interfaces between the fibrils, which some studies define as mechanically weak and responsible for easy slippage of adjacent fibrils [6], while other studies observe the presence of heterogeneous protrusions along such surfaces determining a non-slip kinematics and energy dissipation due to interlocking effects [20]. In addition, while the literature to-date is populated by a number of multiscale and hierarchical approaches to the mechanics of the dragline silk [1][2][3][4][5][6]18], and there is experimental evidence of the partitioning of the spider silk fibres into layers with different mechanical behaviours [7,8], one observes that the grading of the mechanical properties along the radial coordinate of silk fibres has not been extensively investigated.…”