Tough synthetic spider-silk fibers obtained by titanium dioxide incorporation and formaldehyde cross-linking in a simple wet-spinning process.

Due to its unique mechanical properties, spider silk shows great promise as a strong super-thin fiber in many fields. Although progress has been made in the field of synthesizing spider-silk fiber from recombinant spidroin (spider silk protein) in the last few decades, methods to obtain synthetic spider-silk fibers as tough as natural silk from small-sized recombinant protein with a simple spinning process have eluded scientists. In this paper, a recombinant spidroin (MW: 93.4 kDa) was used to spin tough synthetic spider-silk fibers with a simple wet-spinning process. Titanium oxide incorporation and formaldehyde cross-linking were used to improve the mechanical properties of synthetic spider-silk fibers. Fibers treated with incorporation or/and cross-linking varied in microstructure, strength and extensibility while all exhibited enhanced strength and toughness. In particular, one fiber possessed a toughness of 249 ± 22 MJ/m3. This paper presents a new method to successfully spin tough spider-silk fibers in a simple way.

A nitroolefin functionalized BODIPY chemodosimeter for biothiols driven by an unexpected conjugated addition mechanism.

A weakly fluorescent nitroolefin functionalized BODIPY 1 was prepared and rapidly reacted with thiols through an unexpected conjugated addition to the azafulvene ring of BODIPY to generate highly fluorescent BODIPYs 4 and 5. This reaction was applied for the highly selective and sensitive detection of Cys in living cells.