LAUSR

3D‐printed artificial skeletal muscle, which mimics the structural and functional characteristics of native skeletal muscle, is a promising treatment method for muscle reconstruction. Although various fabrication techniques for skeletal muscle using 3D bio‐printers are studied, it is still challenging to build a functional muscle structure. A strategy using microvalve‐assisted coaxial 3D bioprinting in consideration of functional skeletal muscle fabrication is reported. The unit (artificial muscle fascicle: AMF) of muscle mimetic tissue is composed of a core filled with medium‐based C2C12 myoblast aggregates as a role of muscle fibers and a photo cross‐linkable hydrogel‐based shell as a role of connective tissue in muscles that enhances printability and cell adhesion and proliferation. Especially, a microvalve system is applied for the core part with even cell distribution and strong cell–cell interaction. This system enhances myotube formation and consequently shows spontaneous contraction. A multi‐printed AMF (artificial muscle tissue: AMT) as a piece of muscle is implanted into the anterior tibia (TA) muscle defect site of immunocompromised rats. As a result, the TA‐implanted AMT responds to electrical stimulation and represents histologically regenerated muscle tissue. This microvalve‐assisted coaxial 3D bioprinting shows a significant step forward to mimicking native skeletal muscle tissue.