UW Bioengineering Assistant Professor Deok-Ho Kim and collaborators have demonstrated the ability of electroconductive nanopatterned substrates to enhance the maturation and differentiation of skeletal muscle cells. The researchers’ work was featured as the cover article of the first issue of Advanced Healthcare Materials in 2016. 

Skeletal muscle, or the muscle attached to bones that facilitates movement, has a great capacity to repair itself following minor injury. However, tissue lost due to chronic disease or traumatic injury cannot regenerate as well, and current surgical interventions are limited in their capacity to fully restore function.

Engineered skeletal muscle shows promise as a way to replace damaged or diseased tissue. Researchers investigating methods for engineering heart, skin and other tissues have found that factors such as the similarity of the cell culture substrate to the cells’ native environment, and the substrate’s electrical conductivity, can promote the successful differentiation and development of cells into functional tissue.

Past work has shown the benefit of electrically conductive polymers and metals in promoting the differentiation of immature skeletal muscle cells, or myoblasts. However, the combined capacity of both substrate electrical conductivity and topography in promoting myoblast structural organization and differentiation into functional skeletal tissue has not yet been extensively studied.

In their paper, Dr. Kim and his colleagues describe a bioinspired electroconductive myoblast culture platform. First, they created a nanopatterned substrate mimicking the extracellular matrix of native muscle tissue. They then coated patterned and unpatterned substrates with thin layers of either gold or titanium to create an electroconductive surface. Next, they cultured mouse myoblasts on both coated (electroconductive) and bare (non-conductive) substrates for seven days.

The researchers observed that myoblasts organized more readily into skeletal muscle fibers, or myotubes, on nanopatterned substrates. They also discovered that the cells cultured on the conductive, patterned substrates increased their expression of genes and proteins important for myogenic differentiation and maturation. The gold-coated conductive substrates in particular showed the greatest capability for promoting myogenic organization and differentiation.

This versatile platform may have broad applications for engineering different types of mature muscle, such as smooth or cardiac muscle tissue, or for neural tissue. It could also be used to generate tissue for drug testing or therapeutic applications. Furthermore, the findings from this study may also inform future biomedical device or instrument design.

This work was supported by the UW Bioengineering faculty startup fund, NIH R21 grant and Muscular Dystrophy Association Research Grant.