Bioprinting Taurine-Incorporated Gelatin Methacrylate Hydrogels for Enhanced Muscle Tissue Regeneration

Skeletal muscle diseases like myopathies and muscular dystrophies present significant clinical challenges with few effective treatments. To better understand disease mechanisms and accelerate therapy development, robust in vitro muscle models are needed. Extrusion- and light-based bioprinting offer precise fabrication of tissue-like constructs, but creating bioinks that support muscle cell function remains difficult. Here, we report a novel bioink in which taurine is first methacrylated--substituting its -NH2 groups to afford taurine methacrylate (TMA)--enabling covalent integration into gelatin methacryloyl (GelMA) networks. We systematically compared GelMA-Taur (physical blend) versus GelMA-TMA (covalent) hydrogels, assessing mechanical stiffness, swelling behavior, and photocrosslinking kinetics. Incorporating TMA yielded tighter crosslinking control, minimized overcure in DLP-printed features, and improved shape fidelity. SEM revealed finer pore structures and homogeneous TMA distribution, and release assays confirmed prolonged TMA retention compared to rapidly leaching taurine. Photopatterning and 3D printing of complex geometries demonstrated excellent printability of the GelMA-TMA bioink. Finally, C2C12 myoblasts encapsulated in GelMA-TMA scaffolds exhibited accelerated early differentiation, higher myosin heavy chain expression, and more extensive myotube formation than controls. Together, these results establish GelMA-TMA as a printable, mechanically tunable, and biologically active platform for engineering skeletal muscle tissue in disease modeling and regenerative applications.