Advanced 3D bioink featuring damping and antioxidant for micro-nano fabrication

Undesirable mechanical vibrations and shocks, particularly during 3D print process and post-processing biological applications involving musculoskeletal systems, pose critical challenges to structural fidelity and material performance, demanding the bioink capable of impact protection capacity. Here, we develop a damping elastomeric printing bioinks by grafted with glycidyl methacrylate (DEPGM) via a novel multiscale noncovalent-covalent orchestrate mechanical responses strategy. Specifically, results exhibited that molecular level group grafting elevates secondary β-sheet content (up to 150 %) with reduced protein packing density achieves exceptional compressive strength (1.1 MPa), storage modulus (0.26 MPa) and damping capacity (tan δ = 0.072), rivaling natural rubbers (e.g., main component cis-1,4-polyisoprene, tan σ ≈ 0.1). The optimized formulation exhibits shear-thinning behavior compatible with microscaffold printing, microneedle arrays, electrospinning, and microsphere fabrication. Besides, DEPGM demonstrated significant antioxidant activity by effectively enhancing mitochondrial membrane potential and reducing reactive oxygen species (ROS), in nucleus pulposus cells (NPs) under oxidative stress. Moreover, results also indicated that it downregulates matrix metalloproteinase 13 (MMP13) expression while promoting type II collagen (COL2) synthesis, thereby restoring cell microenvironment homeostasis and reconstructing the extracellular matrix (ECM). Thus, DEPGM emerges as a tri-therapeutic material integrating mechanical damping, microenvironment homeostasis, and ECM reconstruction, and establishes a design platform for advanced biomechanical materials via multiscale noncovalent-covalent orchestrate strategy.