Poly(ε-caprolactone)-based nanofibrous scaffold incorporated with decellularized bone extracellular matrix as a potential strategy for bone regeneration

Abstract Background: Critical size bone defect is still a great challenge in orthopedics. Scaffolds with nanofibrous microstructure seems a promising candidate for critical size bone defect repair. Here we fabricated poly(ε-caprolactone)-based nanofibrous scaffold incorporated with bone derived decellularized extracellular matrix (PCL/dB-ECM) to provide a suitable platform for bone regeneration. Methods: dB-ECM was prepared first and different weight ratios of PCL and dB-ECM was blended to fabricate PCL/dB-ECM nanofibrous scaffolds by electrospinning. The physicochemical properties of the nanofibrous scaffolds were investigated. Rabbit bone mesenchymal stem cells (rBMSCs) were seeded on the nanofibrous scaffolds to evaluate cell proliferation, viability, morphology, cytoskeleton spread and osteogenic differentiation. The ability of the scaffolds to promote bone regeneration in vivo was also assessed by being implanted into a rabbit femoral condyle defect model. Results:The microstructure of the PCL/dB-ECM (2:1) nanofibrous scaffold exhibited randomly arranged nanofibers interlaced to each other to form a network structure. The incorporation of dB-ECM into the scaffold improved the bioactivity of PCL, significantly enhanced the attachment, proliferation and cytoskeleton extension of rBMSCs, as well as remarkably promoted osteogenic differentiation of rBMSCs by elevating the expression of osteogenic-related genes and proteins and by enhancing the ALP activity and calcium deposition. Furthermore, in vivo assays demonstrated that PCL/dB-ECM (2:1) nanofibrous scaffold obviously facilitated new bone formation with better trabecular structures and excellent integration with the surrounding tissues. Conclusion: The PCL/dB-ECM (2:1) nanofibrous scaffold showed excellent bioactivity to facilitate rBMSCs proliferation and osteogenic differentiation in vitro, as well as promoted new bone formation in vivo, suggesting the PCL-based nanofibrous scaffolds incorporated with dB-ECM could be a promising strategy for effective repair of bone defect.