Expression Of Integrin-β1,FN And F-actin In Osteogenesis Of Porous Tantalum-bone Interface And Its Significance

Objectives: To observe the morphological features of osteoblast and the expression of Integrin-β1,FN and F-actin in porous tantalum-bone interface,and to explore the biological mechanism of bone integration in porous tantalum-bone interface.Methods: 1 Preparation of materials and experimental groups: The porous tantalum material was made into a cylinder having a diameter of 3 mm and a length of 6 mm.The xenogeneic bone material was made into the same size cylinder,sterilized and kept.Select 48 6-month-old New Zealand white rabbits.Take the animal’s own control method is divided into A,B two groups.Group A was implanted with porous tantalum rod in the left femoral condyle(experimental group),Group B was implanted in the same animal right lateral femoral condyle(control group).Preparation of animal bilateral femoral condylar defect model.In the femoral condyle at the diameter of 3mm,the depth of 6mm of the channel.On the left side(group A),tantalum rods with a diameter of 3 mm and a length of 6 mm were implanted along the channels,the right side(group B)was implanted in the same size xenogeneic bone.Animals were sacrificed at 2,4 and 8 weeks postoperatively and 16 specimens were obtained at each time point.2 Drawing and observation:The daily diet,activity and wound healing of the animals were observed.The animals were sacrificed at 2,4 and 8 weeks after operation.To observe the morphological characteristics of porous tantalum-bone interface in paraffin sections and hard tissue sections.Observation of Osteogenic Characteristics of Porous Tantalum-Bone Interface by Scanning Electron Microscope.The expression of Integrin-β1,FN and F-actin protein was detected by immunohistochemistry.After image acquisition,the IOD value was analyzed by Image-Pro-Plus image analysis software,and the data were statistically analyzed.Results: 1 Gross observation: The implantation of porous tantalum was closely related to the bone at each time point,and the two groups had no inflammatory reaction.2 Paraffin sectioned by HE staining showed: Early tantalum bone interface,a small amount of serous fluid,red blood cells and cellulose exudation,the formation of late trabecular bone,osteogenesis;control group,bone gradually degraded,new bone formation,"creeping replacement".3 Hard tissue sections observation: In the early tantalum bone interface,the new bone and small vessels grew into the pores.The new bone of the late tantalum-bone interface gradually increased and became connected with the bone,and the trabecular bone matured.4 Under scanning electron microscope,osteoblasts were grown in porous tantalum surface and pores,and bone collagen was arranged in bundles.In late stage of bone maturation,bone collagen is bulky and lamellar bone is formed.5 Immunohistochemical analysis showed : Integrin-β1:The expression of porous tantalum group and xenogeneic bone group was higher than that of 8 weeks and 4 weeks after operation,P <0.05;The expression of xenogeneic bone in 2 weeks and 4 weeks was higher than that in porous tantalum group,P <0.05.FN:The expression of porous tantalum group and xenogeneic bone group was higher than that of 8 weeks and 4 weeks after operation,P <0.05;The expression of xenogeneic bone in 2 weeks and 4 weeks was higher than that in porous tantalum group,P <0.05.F-actin:The expression of porous tantalum group and xenogeneic bone group was higher than that of 8 weeks and 4 weeks after operation,P <0.05;The expression of xenogeneic bone in 2 weeks and 4 weeks was higher than that in porous tantalum group,P <0.05.Conclusions: Integrin-β1,FN and F-actin were positive in the tantalum bone interface at 2 weeks after surgery.The peak reached the peak at 4 weeks,decreased gradually,and reached the lowest level at 8 weeks.It showed that the interaction between tantalum and bone appeared in the early stage of osteoblast adhesion to porous tantalum,the morphology of cells changed,and the expression of Integrin-β1,FN and F-actin increased,which promoted the early osteogenesis.Along with the bone tissue gradually mature,combining ability of bone cell surface Integrin-β1 and FN reduce the mechanical stimulation on osteoblast decreased,the activation of F-actin can reduce the number of 3 kinds of bone related protein expression decreased,is conducive to the integration and reconstruction of bone.