| Bone graft and fusion is common tissue transplantation second only to blood transfusion.To restore the bone defeat is a tough problem which orthopedist must face to.Bone defeat exceed 6×6×10mm~3 should be repaired by bone graft.With the development of surgical technic,the requirement of bone graft is greatly rising.Bone graft can be divided into three main type:autogenous bone graft,allogenous bone graft and synthetic bone graft.There are various bone graft being used in clinic and preclinical phase.Because of the nano esculapian developing at a full speed,The study and research of nano-bone graft is developing quickly either.The study is designed to explore the technology of prepare nano-DBM, correlated biological detections and fusion test.By this research,we attempt to offer rationale to nano-DBM as a new bone graft and carrier of bone growth factor.Objectives1.Preparation of DBM,carry out biocompatibility detections and study bone graft and fusion in rabbits,get ready to prepare nano-DBM.2.Preparation of nano-DBM,explore the technology,carry out biocompatibility detections.3.Study bone graft and fusion in neural scute of rabbits,observe the result of bone fusion.Methods1.Use the human homogeneity variant bones which are cut during the operations. (exclude tumor,infection and all kinds of CD.),reject periosteum and all the soft tissue.Split the os integumentale into strip,erasion the bone marrow.Wash the bone repeatedly with purified water,anhydrate with dehydrated alcohol for 2 hours,defat with aether for 1 hour,fanning and drying for one night,reserve in the freezer within-80℃.We adopt improved Urist method to prepare completely DBM:douse in dehydrated alcohol for 2 hours;douse in aether for 1 hour;wash out the aether by distilled water;douse in 0.6N hydrochloric acid for 72 hours, renoveatur the acid every 12 hours,agitate without interrupt during the process; wash out the acid by distilled water;douse in dehydrated alcohol again for 2 hours; douse in aether for 1 hour;dry it to get DBM,reserve in freezer.We detect the DBM by acute toxicity testing,pyrogen test,haemolysis test.2.We pre-porphyrizated the DBM by liquid nitrogen frozen ball mill equipment, then the DBM powder were further porphyrizated by MICROS hygro-form milling and comminuting machine.Moulding the sample and dry it in the vacuum cabinet drier remain 37℃,degerm the DBM with Co60.Electron microscope scans the pre-porphyrizated and the further porphyrizated DBM powder.We detect the nano-DBM by acute toxicity testing,pyrogen test,haemolysis test.3.We degerm the DBM and nano-DBM by Co60,and implant it between lumbar neural scute of rabbits to observe the fusion level.The rabbits are divided into three groups:nano-DBM graft;DBM graft;autogenous bone graft.Observe the fusion state by imageology and histology.Results1.Get human homogeneity variant Demineralized Bone Matrix.There were no experimental animals dead or paralyzed,eating,activity,reaction and general state of health were fine during the acute toxicity testing.The fevescence of each rabbit raised below 0.5℃,was consistent with the regulation of the pyrogen detection.The haemolysis rate of the extraorgan fresh rabbit blood was in permission limit.2.SEM scan shows the diameter of the ball mill sample is between 200 and 600nm; the diameter of MICROS sample is between 50 and 200nm.Moulding and dry the nano-DBM into strip and lump.There were no experimental animal dead or paralyzed,eating,activity,reaction and general state of health were fine during the acute toxicity testing.The fevescence of each rabbit raised below 0.5℃,was consistent with the regulation of the pyrogen detection.The haemolysis rate of the extraorgan fresh rabbit blood was in permission limit.3.All the rabbits endured the operation,none of them succumb to complication of anesthesia,no one paralyzed after operation,no infection occurred,no elimination of graft. The X-ray and CT scan show that there are different fusion levels of each group.ConclusionsNano-DBM is a kind of biomaterial which is virulent,nonirritant,nonpyrogenic, won't revoke immunological rejection.It possesses good biocompatibility and effective bone induction.Nano-DBM is upstanding substitute for autogenous bone in spinal graft fusion... |
