Ryan sikorski@Ryansikorski10
Spider silk is a natural biofiber, & has attracted extensive research becuz of its extraordinary properties including high tensile strength & toughness,[2]sciencedirect.com/science/articl… high thermal conductivity,[3]advanced.onlinelibrary.wiley.com/doi/10.1002/ad… supercontraction,[4]nature.com/articles/nmat1… & peculiar torsion rotational actuation.[5]pubs.aip.org/aip/apl/articl… These excellent properties make spider silk an attractive biomaterial for potential apps in artificial ligaments, heat sinks, artificial tendons, & artificial muscles.
W/ the in-depth study of the structure of spider silk, great progress has been made in the preparation of strong & tough fibers using different technologies such as biotech, nanotech, polymer chemistry, & materials science. The materials used to prepare strong & tough fibers include recombinant spidroins, non-spidroin proteins, polymer materials (e.g., hydrogels, polyurethanes, cellulose, etc.), & their composites.
Artificially mimicking natural spider silk by employing recombinant spidroins is an effective way to prepare artificial spider silk. Recombinant spidroins are generally prepared by genetic engineering techniques, including gene design, cloning, & protein expression in different foreign hosts such as bacteria,[46]pnas.org/doi/full/10.10… yeasts,[47]link.springer.com/article/10.100… insect cells,[48]sciencedirect.com/science/articl… plants,[49]nature.com/articles/nbt06… & mammary gland cells of goats. These artificial spider silk fibers are obtained from a solution of recombinant spidroins by various spinning techniques, including wet-spinning, dry-spinning, & electrospinning. During wet-spinning, the solution of recombinant spidroins is extruded into a coagulation bath, where the spidroins precipitate & the fibers are formed.[51]link.springer.com/article/10.100…
The mechanical properties of the artificial spider silk are also correlated to the concentration of the spinning dope & coagulation bath. It is generally difficult to achieve natural spidroins’ concentration (30–50%, w/v) w/ recombinant spidroins.[17]sciencedirect.com/science/articl…
The Xia group designed a microfluidic spinning chip to mimic the natural spinning apparatus, including shearing & elongational sections. The spinning dope of recombinant spidroins flowed through the microfluidic spinning chip, causing self-assembly & orientation of spidroins to form fibril structures.
advanced.onlinelibrary.wiley.com/doi/10.1002/ad…
Water-soluble recombinant spider dragline silk protein (w/ a low molecular weight of 47 kDa) was adopted to prepare aqueous spinning dope. Artificial spider silks were spun via microfluidic wet-spinning, using a continuous post-spin drawing process (WS-PSD). By mimicking the natural spinning apparatus, shearing & elongational sections were integrated in the microfluidic spinning chip to induce assembly, orientation of spidroins, & fibril structure formation.
The additional post-spin drawing process following the wet-spinning section partially mimics the spinning process of natural spider silk & substantially contributes to the compact aggregation of microfibrils. Subsequent post-stretching further improves the hierarchical structure of the fibres, including the crystalline structure, orientation, & fibril melting.
nature.com/articles/srep3…
We report the rational design, expression, & spinning of intrinsically red-colored artificial silk fibers. A mini-spidroin variant was engineered as a fusion w/ the red fluorescent protein mCherry, expressed @ high yields (20 g/L) in E. coli fed-batch fermentations, & purified under native conditions. Although the presence of the mCherry globular domain reduced spinnability when used alone, blending w/ wild-type mini-spidroins enabled continuous wet spinning into robust, fluorescent fibers.
Our biomimetic spinning approach preserved the correct folding of the mCherry domain w/in the fiber, resulting in stable red coloration & fluorescence, while maintaining mechanical properties comparable to those of other recombinant silks.
nature.com/articles/s4324…
