The role of degradation rate in microchannel scaffold-mediated spinal cord injury repair

Spinal cord injury (SCI) causes axonal regeneration failure and permanent neurological deficits. Biomimetic microchannel scaffolds that mimic native white matter structure can guide directional axonal growth. Nevertheless, it remains unclear how their degradation kinetics impact functional neural repair. Therefore, the study engineered biomimetic microchannel scaffolds with precisely tunable degradation kinetics by integrating decellularized extracellular matrix (dECM) into Pluronic F127 diacrylate (F127DA) and methodically varying the F127DA concentration. Firstly, microchannel scaffolds with various degradation rates exhibited distinct differences in mechanical properties, swelling behavior, microstructure, and cell compatibility. Subsequent long-term evaluation of in situ degradation revealed that the fast degradation group was completely degraded after 3 weeks post-implantation, while partial degradation occurred in the medium degradation group at 12 weeks, and no significant degradation was observed in the slow degradation group at the same time point. Furthermore, animal experiments demonstrated that the medium degradation group promoted linear axonal regeneration, myelination, and angiogenesis, while suppressing fibrotic scarring to a certain degree. In contrast, other groups are difficult to support or even hinder axonal regeneration. This study reveals the complex relationship between scaffold degradation rate and SCI repair outcomes, providing critical theoretical insights for optimizing scaffold design.