Lab-grown muscle isn't new. In 2013, a group of researchers created enough muscle to make a burger that they could eat. But until recently, researchers weren't able to grow muscle that could contract in response to an external stimuli. Now, researchers at Duke University are reporting that they have successfully grown contracting muscle in the lab. The finding, a bioengineering first, means that we may finally be able to engineer muscle that not only looks and feels like real muscle, but that acts like it, too.

To grow contracting muscle in the lab, the researchers started out with a sample of human muscle cell precursors. Then, they expanded the cells and placed them on 3D scaffolding filled with a nourishing gel. According to the researchers, it took a year to develop the right "recipe," but eventually they figured it out: when the researchers subjected the lab-grown muscle to electrical stimuli, it contracted. Moreover, the researchers were able to show that the nerve signaling pathways in the muscle were functional.

Being able to create muscle in a lab that can mimic normal muscle behavior is a big step for medicine. Doctors may soon be able to use this technology to accurately predict the effect of various drugs on the human body, without putting anyone in danger. Furthermore, researchers might one day be able to use biopsied cells to grow muscle that can be used to tailor treatments to individual patients.

The researchers have already demonstrated that the lab-grown muscle's response to cholesterol and performance enhancement drugs matches that of regular human muscle. They now plan to delve more deeply into the effects of various drugs on the muscle. Eventually, they would like to find a way to grow the muscle from stem cells, instead of biopsied cells.

"There are a some diseases, like Duchenne Muscular Dystrophy for example, that make taking muscle biopsies difficult," Nenad Bursac, study co-author and Duke University biomedical engineer, said in a press release. "If we could grow working, testable muscles from induced pluripotent stem cells, we could take one skin or blood sample and never have to bother the patient again."