PRESS RELEASE – Logan, Utah – March 9, 2021 – Researchers at Utah State University are using silkworm silk to grow skeletal muscle cells, improving traditional methods of cell culture, and hopefully this will lead to better treatments for muscle atrophy.
When scientists try to understand disease and test treatments, they generally grow model cells on a flat plastic surface (petri dish). But cell growth on a two-dimensional surface has its limitations, mainly because muscle tissue is three-dimensional. Thus, USU researchers developed a 3D cell culture surface by growing cells on silk fibers wrapped around an acrylic skeleton. The team used both original and genetically modified silkworm silk, which was produced by the silkworms modified with spider silk genes.
The original silkworm silk was previously used as 3D models for cell culture, but this is the first time that genetically modified silkworm silk has been used for skeletal muscle modeling. Elizabeth Varghese, Matthew Clegg, and Jacob Barney of the Department of Biological Engineering, Justin Jones, Thomas Harris, and Xiaoli Zhang of the Department of Biology have published their findings in ACS Biomaterials Science and Engineering.
Cells grown on silkworm silk have been shown to more closely mimic human skeletal muscles than those growing on the usual plastic surface. These cells showed increased mechanical flexibility and increased expression of genes required for muscle contraction. Silkworm silk also encouraged proper muscle fiber alignment, which is a necessary component for strong muscle modeling.
Skeletal muscles are responsible for moving the skeleton, stabilizing joints, and protecting internal organs. Degradation of these muscles can happen for myriad reasons, and it can happen quickly. For example, after just two weeks of inactivity, a person can lose nearly a quarter of their quadriceps muscle strength. An understanding of how muscles atrophy so rapidly at the cellular level must begin, as cells grow to better represent reality.
“The overarching goal of my research is to build better models in the laboratory,” said Elizabeth Varghese, associate professor of biological engineering at the United States University. “Researchers grow cells on these 2D platforms, which are not very realistic, but they give us a lot of information. Based on these results, they usually move to an animal model, and then they move to clinical trials, where the vast majority of them fail. I try to add to that. The first step is to develop more realistic, in vitro models of healthy and diseased tissues. ”