Caption: Engineered muscle fibers are stained with red and green dyes that recognize particular protein markers. The yellow color results from a combination of red and green. The blue dots are cell nuclei.
Credit: Duke University
When you do a hard workout at the gym, or run a marathon, you generate lots of little tears in muscle. This is usually not a problem and may even lead to improved muscle strength—because the injury activates stem cells in the muscle (called satellite cells) that replicate and form new muscle fibers to repair and rebuild the damaged tissue. But when injuries extend beyond the normal wear and tear—a major injury or resection, for example—this amazing self-healing system isn’t enough. That’s when a self-healing, lab-grown muscle transplant would be particularly useful—but we haven’t yet been able to create this in a dish.
But NIH-funded researchers at Duke University in Durham, NC, have now taken a significant step in that direction. They isolated satellite cells from the muscles of rats, genetically engineered them with marker proteins, surrounded them with a special nutrient rich hydrogel, and grew them in small cylindrical molds for two weeks. The result was an elongated bundle of muscle fibers that spontaneously twitched. When stimulated with electric pulses, the muscle bundle contracted—just like real muscle. And, it turned out to have about the same strength as the muscles in a newborn rat.
To test the healing properties of their engineered tissue, the researchers destroyed part of the muscle bundle with a component of snake venom, and waited.
The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.