| Objectives To evaluate the ability of gelatin(Gelatin,G)-hyaluronic acid(HA)-nano hydroxyapatite(n HAP)scaffolds to repair critical jaw bone defects in rats,the physical and chemical properties of composite scaffolds were tested and animal models were established to observe histology.To study the feasibility o f G-HA-n HAP as an osteoinductive material for repairing clinical bone defects.The application of the scaffold material provides the theoretical basis and basis.Methods G-HA-nHAP scaffolds were prepared by freeze-drying and chemical crosslinking.The surface morphology of the scaffolds was observed by scanning electron microscopy(SEM).The porosity and water absorption were measured and analyzed,and the degradation rate of the scaffolds in vitro was measured.Forty-five healthy 8-week-old male SD rats weighing(230±20)g and of clean grade were randomly divided into three groups: experimental group,nano-hydroxyapatite group and blank group,with 15 animals in each group.Bilateral mandibular defects were established between the first and second mandibular molars in all animals.The size of the defect was 3 mm x 3 mm x 3 mm.In the experimental group,G-HA-n HAP bionic scaffolds were placed in the defect area.In the control group,nano-hydroxyapatite was placed in the defect area,while in the blank group,no material was placed in the defect area.Five animals were randomly selected from each group at 4,6 and 8 o'clock after operation.The healing state of the defect area was observed by gross observation,histological observation,MASSON staining and immunohistochemical staining.The expression and distribution of type I collagen(Collagen,I)in the defect area were measured by image-Pro Plus 6.0(IPP 6.0)software at the same time.Mean optical density(MOD)of the reaching site was compared among the groups.Results 1 G-HA-n HAP scaffolds were successfully prepared.Scanning electron microscopy(SEM)showed the porous structure and fiber morphology of the scaffold.Pictures showed that the scaffold material surface was uneven,porous and porous.The pore size was uniform.The average pore size was 80.50 um.The porosity was 96.23% and the water absorption rate was 42.16%.The scaffold provided a supporting mechanism and space for cell adhesion,paving,proliferation and differentiation.2 The model of mandibular defect in rats was successfully established.The defect range was compounded with the criterion of critical bone defect.3 Macroscopic results: At 4 weeks,fibrous healing was formed in the defect area of the experimental group,and connective tiss ue coverage in the defect area of the control group was obvious in the blank group.At 6 weeks,bone-like tissue was filled in the defect area of the experimental group,and in the control group,the defect was partially repaired,the fibrous connective tissue coverage in the central part of the defect area,and the fibrous healing in the defect area of the blank group was completed at 8 weeks.The results showed that the defect was smooth and continuous,and the defect healed basically in the control group,indicating that the defect was rough and the defect was not repaired in the blank group.4 HE staining results analysis: comparison of the results of new bone area: compared in each group,the area of new bone increased with the increase of time.5 Compared with the control group and the blank group,the area of new bone in the experimental group was larger at the 4t h,6th and 8th week(P < 0.05).6 Masson staining analysis: The formation of new bone in the experimental group was faster than that in the blank group and the control group,and the transformation to mature bone was faster than that in the bla nk group and the control group.7 Immunohistochemical analysis: The expression of type I collagen in the defect area increased with the prolongation of time in the same group.Compared with different groups,the MOD value of the experimental group was higher than that of the control group and the blank group in each time period,and the difference was statistically significant(P < 0.05).8 The macroscopical and histological results of the specimens were consistent.Conclusions 1 The scaffold material was successfully prepared in this experiment,which is in accordance with the physicochemical proper ties of previous literatures.2 This study demonstrates that HA-G-n HAP scaffold material can promote the repair of bone tissue defects.Figure47;Table3;Reference 101... |
PDF Full Text Request