Fungal-Derived Chitosan-Based Bioinks Enable Multifunctional Musculoskeletal Tissue Engineering via Enhanced...

Engineering bioinks that combine mechanical robustness with microenvironmental regulation remains a challenge in musculoskeletal tissue engineering. Collagen-based bioinks provide intrinsic bioactivity but have limited structural stability and antibacterial and redox-regulatory functions. Crustacean-derived chitosan (C-CS) can address these limitations, but concerns regarding allergenicity and inconsistent immunomodulation remain. Here, we introduce mushroom-derived chitosan (M-CS), a fungal-derived polysaccharide with distinct compositional and physicochemical characteristics, as a multifunctional component enabling simultaneous physicochemical reinforcement and bioactive regulation. Under physiologically relevant conditions, M-CS exhibits an atypical thermorheological response that enables controlled printing while providing antibacterial and ROS-modulating properties. Incorporating M-CS into a collagen matrix produced composite bioinks (collagen 3 wt%, M-CS 3 wt%, hydroxyapatite 20 wt%) that combine structural reinforcement with bioactive functionality for bone tissue engineering. Particularly, the unique compositional and physicochemical features of M-CS, including its naturally associated β-glucan structures, collectively contribute to enhanced cell-matrix interactions and redox regulation, supporting enhanced osteogenic and angiogenic responses compared to collagen/C-CS/HA and collagen/HA controls. Reduced intracellular ROS levels further establish a pro-regenerative niche via redox-sensitive signaling. Moreover, M-CS/collagen constructs promote robust tenogenic differentiation of human adipose stem cells, demonstrating dual functionality for musculoskeletal interface regeneration.