Three-dimensional bioprinting and tendon repair: application advances and future directions

• 3D bioprinting enables precise construction of muscle-tendon interface mechanical transition layers and tendon-bone interface four-zone gradient structures through patient imaging and computer-aided design. • Multiple 3D printing techniques (e.g., extrusion-based, fused deposition modeling, laser-assisted) are applied to fabricate biomimetic scaffolds, offering trade-offs between resolution, speed, and cell viability. • Functionalized bioinks and multi-technology synergy enhance scaffold bioactivity and mechanical-biological coupling, enabling full-cycle intervention from inflammation to remodeling. • Despite progress, challenges remain including resolution-efficiency trade-offs, shear-induced cell damage, material degradation mismatch, and insufficient long-term safety data, hindering clinical translation.