Role of AKE/GB30 cage loaded with naringin in the repair of spinal bone defect model and its effect on BMPs VEGF signaling pathway / 中国脊柱脊髓杂志

ABSTRACT

Objectives:To observe the repair effect of AKE/GB30 mesh cage loaded with naringin in spinal bone defect model,and explore the mechanism of this biomaterial based on bone morphogenetic proteins(BMPs)-vascular endothelial growth factor(VEGF)signal pathway.Methods:A dental drill was used to make a 7mmx5mmx4mm spinal bone defect model between L5 and L6 vertebrae in 30 New Zealand male rabbits,and AKE/GB30 mesh cages were prepared.The biomechanical properties of AKE/GB30 mesh cages loaded with naringin were tested,and their in vitro drug release behavior was measured.New Zealand rabbits that were successfully modeled were randomly divided into three groups using a randomly digital table method,namely,blank group,autologous bone graft group,and bone graft biomaterial+naringin combined group.Except the blank group,autologous bone transplantation and AKE/GB30 mesh cage loaded with naringin were used for repair.At 6 weeks and 12 weeks after surgery,5 rabbits were taken from each group,and the bone repair status[including bone volume/tissue volume(BV/TV),bone trabecular thickness(Tb.Th)and bone trabecular number(Tb.N)]were detected by micro computed tomography(Micro CD.Real-time fluorescence quantitative polymerase chain reaction(RT-PCR)was used to detect the expressions of bone morphogenetic protein 2(BMP2),VEGF,Runt related transcription factor 2(RUNX2),alkaline phosphatase(ALP),and osteocalcin(OCN)messenger ribonucleic acid(mRNA).Immunoblotting assay(WB)was used to detect the expressions of BMP2,VEGF,RUNX2,ALP,and OCN proteins in bone tissues.Results:AKE/GB30 mesh cages had been successfully manufactured,and its characteristic testing results met the requirements for repairing spinal bone defects.The AKE/GB30 mesh cage loaded with naringin had a maximum compressive strength of 28MPa and a maximum resistance pressure of 15N.At 6 weeks,its cumulative release rate reached(98.15±1.47)％.After 12 weeks,the BV/TV,Tb.Th,and Tb.N,as well as the mRNA and protein expressions of BMP2,VEGF,RUNX2,ALP,and OCN in bone tissues of each group were higher than those after 6 weeks(P＜0.05).The above indicators in the autologous bone graft group and the bone graft biomaterial+naringin combined group were higher than those in the blank group(P＜0.05),and there were no significant differences in the above indicators between the autologous bone graft group and the bone graft biomaterial+naringin combined group(P＞0.05).Conclusions:The effect of AKE/GB30 cage loaded with naringin in repairing spinal bone defect models is equivalent to that of autologous bone graft,which is presumed to achieve by promoting the expressions of BMP2,VEGF,RUNX2,ALP,and OCN.