The McKelvey School of Engineering at Washington University has developed a synthetic approach to polymerize proteins within engineered microbes. The microbes were able to produce titin, a high-molecular weight protein that is used in muscle development. This was then spun into fibers. This material could one day be used as clothing or protective gear. Credit: Washington University, St. Louis
Would you consider wearing clothing made from muscle fibers? They can be used to tie your shoes, or worn as a belt. Although it may sound odd, these fibers can withstand more energy before they break than nylon, silk, nylon or Kevlar.
This muscle can be made without causing any harm to an animal.
The McKelvey School of Engineering at Washington University has developed a synthetic approach to polymerizing proteins in engineered microbes. This allowed the microbes produce titin, a high-molecular weight protein that is used in muscle development. It was then spun into fibers.
Their research was published in Nature Communications on Monday, August 30, 2013.
Its production is affordable and can be scaled. Fuzhong Zhang, a professor at the Department of Energy, Environmental & Chemical Engineering, said that it may be possible to use natural muscle fibers for many applications. These applications could be realized without the need to use animal tissue.
Zhang's lab has produced a synthetic muscle protein called titin. This is one of three major proteins that make up muscle tissue. The large molecular structure of titin is critical to its mechanical properties. Cameron Sargent, a Ph.D. candidate in the Division of Biological and Biomedical Sciences, was the first author of the paper with Christopher Bowen, a recent graduate of the Department of Energy, Environmental & Chemical Engineering.
Zhang stated that muscle fibers have been a topic of long-term interest. For many applications, researchers have tried to create materials that are similar to muscles. "Why can't we just make synthetic muscles directly?" He said. "But they're not going harvest them from animals. We'll use microbes for it."
The research team created bacteria that could be used to make ultra-high molecularweight polymers. These are approximately two megadaltons in weight, 50 times larger than the average bacterial protein. The researchers then used a wet spinning process to transform the proteins into fibers of around ten microns diameter (or a tenth of the thickness human hair).
The group worked with Young Shin Jun, a professor in the Department of Energy, Environmental & Chemical Engineering, as well as Sinan Keten, a professor in Northwestern University's Department of Mechanical Engineering. They then analyzed the fiber structure to determine the molecular mechanisms that allow them to have an extraordinary combination of strength, toughness, and damping ability, or the ability of dissipate heat.
Sargent noted that the fibers can be used to make fancy clothing and protective armor. However, they are more durable than Kevlar (the material used in bulletproof vests). He also pointed out the potential biomedical uses of the material. This synthetic material, which is almost identical to proteins found in muscle tissue and can therefore be used for tissue engineering and sutures, could also be biocompatible.
Zhang's research team isn't content with just synthetic muscle fiber. Their microbial synthesis strategy will allow for more innovative materials in the future. Based on their research, Zhang, Cameron, Bowen and Cameron filed a patent application.
Sargent stated that the beauty of the system was that it can be used anywhere. "We can take protein from different contexts and then put them in this platform for polymerization to create longer, more sustainable proteins for different material applications."
More information: Nature Communications (2021) Microbial production megadalton-titin produces fibers with beneficial mechanical properties. Information from Nature Communications: Microbial production of megadalton Tiin yields fibers with beneficial mechanical properties, (2021). DOI: 10.1038/s41467-021-25360-6
