Aligned microchannel scaffolds for accelerated cell infiltration and differentiation

Porous honeycomb architectures based on TEMPO-oxidized cellulose nanofibers (CNF) have been extensively explored in filtration, separation, and energy-related applications, where directional transport and mechanical stability are essential. While it remains to be studied to translate these structurally efficient architectures into tissue engineering applications, which is challenging due to the stringent requirements for aqueous stability, biocompatibility, and tissue-relevant mechanics. Here, we report a conceptual transition of CNF honeycomb materials from transport-oriented functional media to biologically active, mechanically compliant scaffolds for soft tissue regeneration. Using unidirectional freeze-drying, we fabricated aligned honeycomb scaffolds composed of TEMPO-oxidized CNF, atelocollagen (AC), and β-tricalcium phosphate (TP). This ternary design integrates the structural integrity and anisotropic templating capability of CNF with the bioactivity of AC and the stiffness modulation provided by TP. The optimized scaffold exhibits a highly ordered honeycomb channel architecture with an average channel size of approximately 70 μm, excellent aqueous stability, and soft-tissue-relevant mechanical properties. In vitro studies using C2C12 myoblasts demonstrate not only high cytocompatibility but also efficient cell infiltration depth and promoted myogenic differentiation along the aligned channels, when compared with the random porous control sample. The proposed CNF-based honeycomb scaffold serves as a versatile platform for aligned soft tissue engineering, like skeletal muscle and potentially biologically integrated bioreactor systems that meet the functional demands of regenerative medicine.