Production Of High-performance Recombinant/Regenerated Silk Protein Fibers

Silks of spider and silkworm are proteinaceous biomaterial materials with excellent mechanical properties,good biocompatibility,and biodegradability,which can be widely used in the fields of biomedical,electronic,textile,and environmental engineering.However,the mass production of spider silk from nature is not possible because of spider's cannibalistic and territorial behavior.Although silkworm cocoon silk can be obtained in large quantities,its performance is far lower than spider silk.Therefore,it is hoped that a large number of recombinant/regenerated silk fibers with excellent properties can be obtained by artificial spinning,which can be applied in different fields as new biological materials.In this study,we produced high-performance artificial eggcase silks and regenerated silk fibroin fibers with used recombinant eggcase silk proteins and regenerated silk fibroin.Firstly,the production of artificial eggcase silks.TuSp1 and TuSp2 is the major and minor component of the eggcase silk of Spider Nephila antipodiana,respectively.TuSp1-N2RPC and TuSp2-RP were used in the production of artificial eggcase silk.The results show that a certain proportion of TuSp2-RP can improve the mechanical properties of artificial eggcase silks.The best molar ratio of TuSp1-N2RPC to TuSp2-RP in the spinning dope was 6:1.The average peak stress is 391±16 MPa,strain at break is 9±1%,Young's modulus is 8±1 GPa,and energy to break is 21±2 MJ/m³.Except for strain,its performance has been improved,and the average peak stress is 73%higher than its natural counterpart.Secondly,the production of RSF fibers.Degradated regenerated silk fibroin(De-RSF)and undegraded regenerated silk fibroin(Un-RSF)can be obtained by different methods from silkworm cocoon silk.0.02-0.06 M Ca²⁺in the spinning dope can improve the mechanical properties of De-RSF fibers.The average Un-RSF fiber's peak stress is 587±60 MPa,strain at break is 12±3%,Young's modulus is 15±3 GPa,and energy to break is 46±17 MJ/m³.Its performance which except for strain at break has been improved,and the average peak stress is 56%higher than its natural counterpart.The results of this study not only demonstrate the preparation of high-performance recombinant/regenerated silk fibers but also provide the technical guide for producing composite fibers of spider and silkworm silks.Besides,we can explore the effect of metal ions on the properties of artificial protein fibers.The preparation of high-performance recombinant/regenerated silk protein fibers may also create more application potentials for silk-like materials.