Abstract

Restoring the natural structure and morphology of alveolar bone remains a significant clinical challenge in bone defect repair. Recent studies have emphasized the critical role of the structural features of biomaterials in regulating the organized arrangement of stem cells during the repair of critical-size bone defects. Inspired by the aligned structure of the lamellar bone extracellular matrix (ECM), anisotropic gelatin methacryloyl/oxidized chitosan hydrogels (referred to as GelMA-2%OC-T) were developed by employing directional freeze-casting combined with mechanical training, consisting of well-aligned fibrous structures. The fracture toughness of the GelMA-2%OC-T hydrogels in the Y-direction (0.96 MJ/m 3 ) was ~3.8 times that of the X-direction (0.25 MJ/m 3 ). GelMA-2%OC-T samples demonstrated excellent biocompatibility, effectively guiding the oriented alignment of neural crest-derived stem cells (NCSCs) when seeded for 24 h, and promoted osteogenic differentiation in vitro by activating the ITGA7-COL1A1 axis, as revealed by transcriptome sequencing. Implantation of GelMA-2%OC-T scaffolds into rabbit alveolar bone defects for 8 weeks facilitated new bone formation and restored the original structure and morphology of the alveolar bone. Thus, this study offers a novel strategy for designing artificial biomaterials by mimicking the aligned structure of the lamellar bone ECM aimed at directing bone regeneration and restoring natural structures.