Functionalized acellular periosteum guides stem cell homing to promote bone defect repair

The periosteum plays a key role in bone tissue regeneration, especially in the promotion and protection of new bones. However, among the bone repair materials, many biomimetic artificial periosteum lack the natural periosteal structure, stem cells, and immunoregulation required for bone regeneration. In this study, we used natural periosteum to produce acellular periosteum. To retain the appropriate cell survival structure and immunomodulatory proteins, we grafted the functional polypeptide SKP on the surface collagen of the periosteum via an amide bond, providing the acellular periosteum with the ability to recruit mesenchymal stem cells. Thus, we developed a biomimetic periosteum (DP-SKP) with the ability to promote stem cell homing and immunoregulation in vivo. Compared to the blank and simple decellularized periosteum groups, DP-SKP was more conducive to stem cell adhesion, growth, and osteogenic differentiation in vitro. Additionally, compared with the other two groups, DP-SKP significantly promoted mesenchymal stem cell homing to the periosteal transplantation site, improved the bone immune microenvironment, and accelerated new lamellar bone formation in the critical size defect of rabbit skulls in vivo. Therefore, this acellular periosteum with a mesenchymal stem cell homing effect is expected to be used as an extracellular artificial periosteum in clinical practice.