Repair of rat cranial bone defect by using amniotic fluid-derived mesenchymal stem cells in polycaprolactone fibrous scaffolds and platelet-rich plasma.

Introduction: Tissue regenerative medicine strategies, as a promising alternative has become of major interest to the reconstruction of critical size bone defects. This study evaluated the effects of the simultaneous application of polycaprolactone (PCL), amniotic fluid mesenchymal stem cells (AF-MSCs) and platelet-rich plasma (PRP) on the repair of rat cranial bone defects. Methods: The AF-MSCs were isolated at the end of the second week of pregnancy in rats. PRP obtained from rat blood and the random PCL fibrous scaffolds were prepared using the electrospinning method. Circular full thickness (5 mm) bone defects were developed on both sides of the parietal bones (animal number=24) and the scaffolds containing AF-MSCs and PRP were implanted in the right lesions. Thereafter, after eight weeks the histological and immunohistochemistry studies were performed to evaluate the bone formation and collagen type I expression. Results: The spindle-shaped mesenchymal stem cells were isolated and the electron microscope images indicated the preparation of a random PCL scaffold. Immunohistochemical findings showed that collagen type I was expressed by AF-MSCs cultured on the scaffold. The results of hematoxylin and eosin (H&E) staining indicated the formation of blood vessels in the presence of PRP. Additionally, immunofluorescence findings suggested that PRP had a positive effect on collagen type I expression. Conclusion: The simultaneous application of fibrous scaffold + AF-MSCs + PRP has positive effects on bone regeneration. This study showed that PRP can affect the formation of new blood vessels in the scaffold transplanted in the bone defect.