Magnetic Bioprinting and Actuation of Stretchable Muscle Tissue

Engineering tissues with precise, long-lasting shapes and the capability for mechanical stimulation remains challenging. This study addresses this challenge by developing a next-generation magnetic bioprinting approach to create anisotropic, shape-controlled, scaffold-free, and stretchable skeletal muscle constructs. Murine skeletal muscle cells and human induced pluripotent stem cell-derived skeletal muscle cells, labeled with iron oxide nanoparticles, are magnetically bioprinted into wrench-shaped tissues. Their magnetic properties allow these tissues to be clipped onto magnetic needles, preserving their shape over two weeks of culture while promoting anisotropic differentiation and myoblast fusion. Additionally, the magnetic tissues can be stretched by up to 100%, enhancing their anisotropy and improving muscle maturation. This magnetic toolbox demonstrates significant advancements in muscle tissue engineering, as evidenced by enhanced indicators of myoblast differentiation, including cell fusion, increased myogenic maturation, and contractility. These findings highlight the potential of magnetic-based techniques for developing advanced muscle-on-chip systems and other complex tissue constructs.