Prof Mark Lewis talks about the benefits of lab-grown muscle.
Last month, Dutch scientists unveiled the world’s first lab-grown burger. They took cells from a cow and turned them into strips of muscle, which were then combined to make a patty that, while failing to impress gourmands, did at least reignite the debate on the best ways to address global food shortage.
It was a headline-grabbing take on stem cell research but then scientists have been doing similar things for years. For instance, researchers are hard at work trying to grow human tissue to replace worn-out or diseased muscle, nerve cells or cartilage.
Mark Lewis, a professor of musculoskeletal biology, and his colleagues at Loughborough University and University College London are using stem cell research to grow human muscles in a lab. Stem cells are our ‘mother cells’ – essentially, they possess the potential to grow into any type of cell in the body. In Lewis’s research, the ‘grown’ muscles are put through their paces in the laboratory’s mini gyms. This Friday, the team will be showcasing its research at Science Uncovered, a free event at London’s Natural History Museum.
Lewis wants to understand the effects different types of exercise have on performance. He hopes the results of his research will enable elite athletes to perfect their training regimes, as well as aiding older people with their exercise programmes and helping those with degenerative diseases.
‘There is no longer a one-size-fits-all method when it comes to exercise,’ he says. ‘One of the big debates is around the most appropriate exercise prescription for individuals. For example, regimes such as high intensity interval training (HIIT) might be the answer.’
Lewis’s research involves taking human muscle biopsies, extracting the cells and then reconstituting them with collagen to build new muscle.
‘Collagen is the most abundant organic molecule in the human body,’ he says. ‘Your muscles are made up of muscle cells and collagen, so we are trying to reconstitute that to make a muscle that mimics how human muscles behave. These in vitro muscle models are around two centimetres long.’
The muscle is then strapped into the lab’s mini gym. ‘We have a motor that stretches it and we can choose different regimes to simulate different types of exercises,’ says Lewis. ‘We can also use electrodes to make the muscle pulse to test its performance.’
Lewis says his research is at the preclinical testing stage. ‘Rather than get people into the lab, we can get their cells and exercise them
in our mini gyms,’ he says.
‘We can then see how they respond and use this information to see what you would then do with the human being.’
This could benefit those with degenerative diseases such as osteoarthritis. ‘If we can get muscle biopsies from people with osteoarthritis then we can exercise their model in our labs,’ he says. ‘We may be able to give their physiotherapist an idea of which types of exercises might benefit their condition.’
Lewis is part of the Arthritis Research UK Centre for Sport, Exercise and Osteoarthritis and some of his research is looking into the effectiveness of explosive strength training.
‘This is one of a number of important strands of work as part of our centre,’ says Jane Tadman, spokeswoman for Arthritis Research UK. ‘The main aims of the centre are to prevent injury in both elite and recreational athletes, and to reduce the risk of developing osteoarthritis as a result of injury.
‘We know exercise is good for everyone, whether or not they have arthritis, as it builds up the muscles that support the joints, but we’re not clear what type or level of exercise is best. If we could establish that, we could then target specific exercises at individuals with more effect.’
The big question is whether Lewis has the potential to implant muscle tissue into patients who have lost muscle through surgery, accidents or sports injuries.
‘To me, it’s a question of size,’ he says, ‘and I think this is also relevant for the burger research. The researchers say the technology could be a sustainable way of meeting the growing demand for meat and depleting livestock supplies. But could you get enough cells to make ten million burgers to feed everyone?
‘The same is true of our research: how do we get enough material to make the muscles that are in something like your quadriceps? That’s the challenge with transplantation.’
The technology might not be quite there for transplants on such a large scale but Lewis says he is also working with the Engineering and Physical Sciences Research Council to see if they can recreate enough cells for some of the smaller muscles in the body.
‘The muscles around the eye are tiny,’ he says, ‘so we might be able to recreate them for facial reconstruction. Or perhaps the muscles in the fingers. But this is a very niche and specialist market and we’re not there just yet.’
Professor Lewis and his fellow scientists are showcasing their work at Science Uncovered, at the Natural History Museum. www.nhm.ac.uk