Spider silk is known for its incredible strength. For its size, it is stronger than most man-made materials, and scientists have long dreamed of a way to synthesize it.
Unfortunately for us humans, there are problems with synthesizing spider silk. Professor Fuzhong Zhang at the Washington University McKelvey School of Engineering explained that there is a problem with getting the amount of nanocrystals in synthetic silk right. Nanocrystals are an important component in making the silk strong.
“Spiders have figured out how to spin fibers with a desirable amount of nanocrystals,” explained Zhang. “But when humans use artificial spinning processes, the amount of nanocrystals in a synthetic silk fiber is often lower than its natural counterpart.”
To solve this problem, Zhang’s lab created new silk genetic sequences with code that emphasized the creation of nanocrystals.
“After our previous work, I wondered if we could create something better than spider silk using our synthetic biology platform,” said Zhang.
The newly designed protein turned out to be simpler than previous attempts at synthetic spider silk and easier for bacteria to synthesize in culture.
The resulting fibers are tougher than steel and kevlar; they are also stronger than some spider silks. The scientists at Zhang’s lab are optimistic about what this breakthrough could mean, hoping that this research could lead to more in the near future.
“This demonstrates that we can engineer biology to produce materials that beat the best material in nature,” said Zhang.
The small project examined just three – out of thousands – of possible variations on spider silk that could be engineered to potentially improve its properties for use by humans. This means that there are likely many more high performing materials to be manufactured based on spider silk alone, not to mention the endless possibilities of tweaking thousands of other natural products in the world.