Mechanically strong globular protein-based fibers via microfluidic spinning technique.

Abstract

Typical proteins for the formation of light weight and mechanically strong biological fibers are composed of folded rigid and un-folded flexible units. In stark contrast to fibrous proteins, globular proteins are generally not regarded as a good candidate for fiber production due to their intrinsic structure defects. Thus, it is challenging to develop an efficient strategy for the construction of mechanically strong fibers by spherical proteins. Here, we demonstrate a new type of robust protein fiber by microfluidic technique, in which globular bovine serum albumin (BSA) is spun efficiently. Remarkably, the toughness of the fibers was up to 143 MJ/m 3 , and after post-stretching treatment, their breaking strength increased almost to 300 MPa due to the induced long-range ordered structure in the fibers. The performance is comparable or even higher than that of many recombinant spider silks or regenerated silkworm fibers. Thus, this work opens a new way for making biological fibers with high performance.