A Functional 3D Biomimetic Osteon Accelerates Bone Regeneration

The distinctive structure and composition of the Haversian canal within osteons play a pivotal role in sustaining the nutritional supply to individual bone cells. Consequently, the osteon's inherent advantages in facilitating bone repair have garnered increasing attention. However, most existing designs emulate only partial aspects of the osteon's architecture, failing to replicate its structure and functionality comprehensively. This study aimed to develop a functional 3D biomimetic osteon to enhance bone regeneration. To achieve this, oriented nanofibers mimicking osteonal lamellae are fabricated via electrospinning, while a biomimetic blood vessel, simulating the Haversian canal, is constructed using microfluidics technology. The biomimetic blood vessels, seeded with rat umbilical vein endothelial cells, secreted bone morphogenetic protein to stimulate osteogenesis and released platelet-derived growth factor to promote angiogenesis, further supporting osteogenesis processes. The nanofibers, composed of type I collagen and nano-hydroxyapatite, released calcium ions, can facilitate the recruitment of bone marrow mesenchymal stem cells, enhance their adhesion to the fibers, and promote osteogenic differentiation. These findings demonstrate that replicating both the natural structure and function of bone tissue provides a superior strategy for bone repair.