Extensible and self-recoverable proteinaceous materials derived from scallop byssal thread

Abstract

Biologically derived and biologically inspired fibers with outstanding mechanical properties have found attractive technical applications across diverse fields. Despite recent advances, few fibers can simultaneously possess high-extensibility and self-recovery properties especially under wet conditions. Here, we report protein-based fibers made from recombinant scallop byssal proteins with outstanding extensibility and self-recovery properties. We initially investigated the mechanical properties of the native byssal thread taken from scallop Chlamys farreri and reveal its high extensibility (327 ± 32%) that outperforms most natural biological fibers. Combining transcriptome and proteomics, we select the most abundant scallop byssal protein type 5-2 (Sbp5-2) in the thread region, and produce a recombinant protein consisting of 7 tandem repeat motifs (rTRM7) of the Sbp5-2 protein. Applying an organic solvent-enabled drawing process, we produce bio-inspired extensible rTRM7 fiber with high-extensibility (234 ± 35%) and self-recovery capability in wet condition, recapitulating the hierarchical structure and mechanical properties of the native scallop byssal thread. We further show that the mechanical properties of rTRM7 fiber are highly regulated by hydrogen bonding and intermolecular crosslinking formed through disulfide bond and metal-carboxyl coordination. With its outstanding mechanical properties, rTRM7 fiber can also be seamlessly integrated with graphene to create motion sensors and electrophysiological signal transmission electrode.

Aqueous spinning of robust, self-healable, and crack-resistant hydrogel microfibers enabled by hydrogen bond nanoconfinement

“…Nature produces diverse robust water-involving fibrous materials such as muscle fibers, nerves, and silks towards a range of different functionalities from safety, capture, water collection, sensing, to adaptive actuation 1 . These natural fibers have inspired the fabrication of numerous biomimetic hydrogel fibers with tailorable intelligent functions based on either polypeptides or non-peptide synthetic polymers [2][3][4][5][6] . However, due to the water-plasticizing nature and lack of hierarchical structure design, the mechanical performance of synthetic hydrogel fibers is often limited, which suffer from low strength and robustness to tolerate various damages.…”

Recent developments in artificial spider silk and functional gel fibers

“…Reproduced with permission: Copyright 2022, Nature. 48 (C) Photographs of the rTRM7 fiber during the drawing process. Reproduced with permission: Copyright 2022, Nature.…”

“…Reproduced with permission: Copyright 2022, Nature. 48 (D) Schematic of biomimetic spinning: A concentrated solution of NT2RepCT was extruded through a glass capillary into a spinning bath containing an aqueous buffer, pH 5. The pH change and shear forces mimicked the conditions of native silk spinning and induced immediate fiber formation.…”

“…(B) Schematic of the fabrication of rTRM7 fiber by the drawing process. Reproduced with permission: Copyright 2022, Nature 48 . (C) Photographs of the rTRM7 fiber during the drawing process.…”

“…(C) Photographs of the rTRM7 fiber during the drawing process. Reproduced with permission: Copyright 2022, Nature 48 . (D) Schematic of biomimetic spinning: A concentrated solution of NT2RepCT was extruded through a glass capillary into a spinning bath containing an aqueous buffer, pH 5.…”