IADR Abstract Archives
Neutrophil-mediated In-vivo Bone Regeneration in a Rabbit Calvarial Defect Model
Objectives: Bone reconstruction is a challenging issue in the regeneration of surgically removed bone and disease-related bone defects. It is known that the immune system exerts positive immuno- modulatory effects on tissue repair and regeneration. The purpose of this preliminary study was to evaluate the in-vivo efficacy of autologous neutrophils on osteogenesis and angiogenesis using a rabbit calvarial defect model. In addition, combined effect of neutrophils with beta-tricalcium phosphate (β-TCP) on bone defect healing was also examined.
Methods: Eighteen rabbits, each with surgically created two calvarial bone defects (10mm diameter), were randomly divided into three groups (n=36). Group 1: single-application of neutrophils +fibrin carrier vs fibrin carrier alone (Control), Group 2: single-application of neutrophils+ β-TCP+fibrin carrier vs β-TCP+ fibrin carrier alone, Group 3: repetitive application of neutrophils+fibrin carrier vs fibrin carrier alone. Animals were sacrificed and the treatment outcomes were evaluated by micro-CT and histological analysis at 4 and 8 weeks post operatively.
Results: Micro-CT analysis showed that application of neutrophils enhance more bone formation compared to the control at 8 weeks (P<0.05). Interestingly, repetitive application of neutrophils significantly increased the amount of new bone formation accompanied by new capillary vasculature regeneration as compared with the control group (P<0.05). In addition, immunohistochemistry results showed that expression of CD31 increased significantly in neutrophil treated group compared with control at 8 weeks which is an evidence for vessel formation. However, there was no significant difference in new bone formation in combined application of β-TCP with neutrophils as compared with β-TCP alone (P> 0.05).
Conclusions: This preliminary in vivo study demonstrated the potential efficacy of standardized neutrophil-mediated response for bone regeneration by promoting new bone and vasculature. This new strategy, if proven feasible in subsequent studies, can be applied clinically in the field of oral and maxillofacial surgery, bringing enormous benefits to patients.
Methods: Eighteen rabbits, each with surgically created two calvarial bone defects (10mm diameter), were randomly divided into three groups (n=36). Group 1: single-application of neutrophils +fibrin carrier vs fibrin carrier alone (Control), Group 2: single-application of neutrophils+ β-TCP+fibrin carrier vs β-TCP+ fibrin carrier alone, Group 3: repetitive application of neutrophils+fibrin carrier vs fibrin carrier alone. Animals were sacrificed and the treatment outcomes were evaluated by micro-CT and histological analysis at 4 and 8 weeks post operatively.
Results: Micro-CT analysis showed that application of neutrophils enhance more bone formation compared to the control at 8 weeks (P<0.05). Interestingly, repetitive application of neutrophils significantly increased the amount of new bone formation accompanied by new capillary vasculature regeneration as compared with the control group (P<0.05). In addition, immunohistochemistry results showed that expression of CD31 increased significantly in neutrophil treated group compared with control at 8 weeks which is an evidence for vessel formation. However, there was no significant difference in new bone formation in combined application of β-TCP with neutrophils as compared with β-TCP alone (P> 0.05).
Conclusions: This preliminary in vivo study demonstrated the potential efficacy of standardized neutrophil-mediated response for bone regeneration by promoting new bone and vasculature. This new strategy, if proven feasible in subsequent studies, can be applied clinically in the field of oral and maxillofacial surgery, bringing enormous benefits to patients.