Histology And Imaging Study Of CASP

Objective:absorbable material is gradually emerging in recent years and the clinical application of new biological materials,goodcompatible with organizations and can be absorbed by the body degradation characteristics.This study used PDLLA and calcium phosphate add into PDLLA different ratio of production Centrum-vertebra-fracture-repairing absorbable supporting plugger,(CASP)and the cylindrical materials,experimental animals were implanted femoral condyle and muscle tissue,By observing the process of degradation of appearance,the shape changes,materials to the surrounding tissue and its impact on the process of being replaced.The objective is to identify three kinds of materials can be absorbed within the vertebrae support for implantation in the biocompatibility and imaging Changes in order to further clinical application to provide the basis of animal experiments.Methods:60 rabbits were randomly divided into three groups,namely 6%β-TCP/PDLLA,6%β-TCP/PDLLA,pure PDLLA groups,each 20.will be made of three cylindrical materials and CASP Were implanted in animals,general observation after operation.Four weeks,12 weeks,six months each of eight animals were randomly selected to X-ray;4,8,12,16,half year after operation eight experimental animals were killed each group,femoral condyle,the gluteus muscle tissue,CASP,cylindrical materials together with the surrounding tissue removed,observe the patterns change,and contralateral normal tissue contrast.a cylindrical materials in muscle were washing,drying later,scanning electron microscopy,the femoral condyle and the rest of the muscles around the material,together with the respective organizations to do bone and muscle tissue biopsy.evaluate three kinds of composite materials'compatibility in different organizations.Results:All 60 rabbits were included in the final analysis.Incision were normal healing.In muscle tissue,absorbent material was wrapped with thin fibrous tissue is evident,Among three groups of the experimental groups(6%TCP/PDLLA complex, 12%TCP/PDLLA and pure PDLLA),the bone tissue implant had no abnormal changes. (1),Observation of three kinds of materials implanted into muscle After 4 weeks,among three experimental groups,it was obvious the formation of a layer of fiber membrane between muscle tissue and material,and has mild foreign body reaction.After 12 weeks,in,fiber membrane can be seen in cylindrical material,the other two groups had aslo formed fiber membrane,but the wall were thicker than 6% TCP/PDLLA group,loose fiber membrane has formed around CASP among three experimental groups,we can concluded that 12%TCP/PDLLA degradation faster than the other two materials and no inflammatory response,in the blank group,fibers tissue is looser.After 24 weeks,in 6%TCP/PDLLA group,the fiber around cylindrical material became thinner significantly and the continuity of the structure is fine;in 12%TCP/PDLLA group,fiber membrane formed in cylindrical material,the wall is thin and loose,12%TCP/PDLLA group's degradation rate is significantly faster than the other two groups,in the blank group fiber growed and had no inflammatory response.(2),Observation of three kinds of cylindrical materials implanted into femoral condyle.after four weeks,it is can be seen that material and bone tissue work closely by demineralized bone biopsy.Among three groups of laboratory animals,periosteal cell growth can be seen around the cylindrical materials,in the blank group,the connective tissue covered the surface defects;after 12 weeks,cylindrical materials implanted into femoral condyle was completely embedded by surrounding tissue.in 6%TCP/PDLLA group,the growth of cartilage can be seen around the cylindrical materials,rich bone marrow can be seen out of cartilage.Between The remaining two groups,the growth of cartilage can aslo be seen around the cylindrical materials; blank group cartilage growth is less than three experimental group.After 24 weeks, Between 6%TCP/PDLLA group and 12%TCP/PDLLA group,bone formation was faster than PDLLA group.In 6%TCP/PDLLA group,it has formed dense bone tissue around the cylindrical material,and Havers' canals can be seen.12%TCP/PDLLA group's degradation was more obvious than the other two groups,trabecular pattern around the cylindrical material was neat,Compact bone formed.In PDLLA group, there is a cartilage growth around cylindrical material,but generating capacity is less than the other two groups,Three experiment groups had no inflammatory response. Blank group has new bone formation but obviously lacunar.(3),electron microscope scanning of 6%TCP/PDLLA cylindrical material Eight weeks after implantation,leakage is visible on material surface and deep layer has wormhole-like holes;after 16 weeks,more leakage is visible on material surface and deep layer has more wormhole-like holes;alter 24 weeks,a thin "shell"-like structure has formed and in the internal fissures formed no distorting twist change.(4),X-ray checkX-ray check found that between 6%TCP/PDLLA and 12%TCP/PDLLA group,Material edges gradually blurred and the volume gradually narrowed,12% TCP/PDLLA group was more obvious.Conclusion:1.Three different formulations of material and its degradation product has good organization compatibility.2.6%TCP/PDLLA and 12%TCP/PDLLA group may have a ossific stimulate role.3.6%TCP/PDLLA degradation rate matched the growth rate of bone tissue.It may be a good bone defect repair materials.4.12%TCP/PDLLA degradation was faster than the other two groups,so as a bone repair materials,it may lose supporting role to fracture site because of fast degradation in the early fracture healing.