Aligned nanofibers in biomimetic periosteal extracellular matrix/poly(ε-caprolactone) membranes enhance bone regeneration via the ITGB1/PI3K/AKT pathway

Periosteum plays an indispensable role in bone regeneration by providing osteogenic and angiogenic cues essential for tissue repair. In cases of severe bone defects or nonunion, autologous vascularized periosteum transplantation remains a highly effective clinical solution. However, its application is restricted by donor site morbidity and limited tissue availability, thereby underscoring the urgent need for artificial periosteum that mimics both the composition and structure of the native counterpart. Among these properties, the topological morphology of the periosteum is believed to be critical, yet its influence on bone regeneration remains insufficiently understood. In this study, biomimetic periosteum membranes composed of coaxially electrospun poly(ε-caprolactone) (PCL) and periosteal extracellular matrix (pECM) were fabricated with either random or aligned nanofiber architectures. Their osteogenic potential was systematically evaluated <i>in vitro</i> and <i>in vivo</i>. Compared to the randomly arranged structure, aligned pECM (aPEC) significantly enhanced the adhesion, alignment, and osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) by activating the ITGB1/PI3K/AKT signaling pathway, whereas these effects were not observed in pure PCL membranes. These findings demonstrate that aligned topological morphology in biomimetic periosteum plays a pivotal role in directing stem cell behavior and promoting bone regeneration. This work provides mechanistic insight and technical guidance for the future design of functionally enhanced artificial periosteum for bone tissue engineering applications.