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Skull shaping technique was a kind of the oldest and commonest skill in neurosurgery. And due to trauma, infection, attacked and destroyed tumor, and excision of skull by encephaledema and high-pressure in skull, after be operated, skull was deficiency. To make artistic and prevent brain tissue from being damaged again, and recover leakproofness of cranial cavity and therapy syndrome of skull deficiency, it was necessary for patients to be operated on cranioplasty. At present, there were three kinds of materials domestic and overseas:metal titanium, medical silica gel and bone cement. But above materials were belzong to several disadvantages such as aging, damaging, uneasy typing and biocompatibility low, meanwhile could not replace the defect of authentic repairing biology. Hitherto, there was no one kind of skull patching material, which not only could be stable, but also achieved osteogenesis coalescence in skull, and realized repairing of biology of genuine significance. The study was from my tutor and done at Tsinghua University molding centre, to apply for computer assisting design, celerity molding precipitation technique in low temperature for HA-PLGA-BMP-2of skull patching material, The purpose of the study was to evaluate effective histocompatibility and osteogenesis, and provide zoopery evidences, which would be applied to clinical study.The experiment was bone in five groups:blank group, Titanium control-group, silicon rubber group, HA group. Those groups were defined as control group. And the group which was implanted repair material of skull bone-HA-PLGA-BMP-2was experimental group. The subject New Zealand Rabbits were implanted HA-PLGA-BMP-2skull patching biomaterials in radius with their left foreleg (sawed radius about1.5cm in advance, and obtained model of radius defect). Observing rabbits’condition after being operated at1st week, involved in wound healing, feeding, activity, the bowels and so forth, and expiratory dyspnea, diarrhea, death and so on. By observing4th week,8th week,12th week experiment indexes, to know about changes of experimented rabbits’ condition, the result was obtained about blood biochemistry, blood routine, liver and kidney functions. Comparing the BMP in the operated region, on the other side to the operated BMD measured by BMD machine for each observation point to observe changing of BMD. X-ray was applied to observe changing osteogenesis. At Each observation point, experimented rabbits, was killed by the gas embolism method, after that got specimens around tissue of material about1cm was taken, to make HE and observe inflammatory reaction and the changing of osteocyte. By HE for tissues of livers and kidneys of rabbits, we observed the variation of viscera.All of experimented animal were lively and healthy by a period of observing, some indexes including activity, bite and sup, growing and so on. And there were no conditions, deficient spirit, fever, hypofunction. And the condition was better and better after implanted, meanwhile no red and swollen for face, nigrescence, high temperature region, ulcer and un-infection. To calculate the account of cell by the blood routine WBC(7.62±1.62x109/L), RBC(5.03×±0.79×109/L), lymphocyte(1.46±0.96×109/L), the all values were normal range; there was no significant between experimented group and control group included AST (35.11±13.15U/L), ALT(42.13±12.19U/L), carbamide(8.14±1.25mmol/L), and creatinine(67.11±12.94umol/L). Bone mineral density:up to63%of the normal bone tissue at8weeks; more than95%at12weeks. A small amount of inflammatory cells was observed by HE staining at4weeks, there was no inflammatory cells at8,12weeks. The formation of bone cells was not observed at4weeks and just could be seen at8and12weeks; X-ray:The fracture line was more fuzyy than before at8weeks and disappeared at12weeks. A small amount of inflammatory cells was observed through HE staining of each group in control groups, no inflammatory cells at8and12weeks, bone cell tissue was not seen at4,8and12weeks. HE staining showed no destruction of normal cells and abnormal tissue growth. The bone density of control group could not reach normal BMD. X-ray revealed clear fracture line in each control group at4,8and12weeks and no new bone formation.As one kind of skull repairing materials, HA-PLGA-BMP-2material possessed good ossification, would become one of the best skull repair materials comparing with the other related ones.
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