The Biocompatibility And Lumber Interbody Fusion Of Animals Research Of The PLGA

Objective:Bone defect and nonunion are still the dilemmas of reconstructive orthopedic surgery nowadays.Autograft,allograft together with metal internal fixation are often applied repairing methods,which, however,have their intrinsic disadvantages and cannot meet the demands in all situations.Autologous bone grafts are considered to be the golden standard against which the other skeletal substitutes are measured,as it owns both of the osteoinductive and osteoconductive properties and shows optimum skeletal incorporation without immune rejection,but the complications at donor sites,limitations in shape,size and amount of graft are the major drawbacks of the technique.Furthermore,the additional surgery makes patient undergo more injuries to body and more economic burden.Allogeneic bone material can be used to overcome these disadvantages and meet the requirements of bone grafting,but the inevitable immune response and the risk of virus disease transmission make surgeons hesitate to choose it.In addition,the application of allogeneic bone material has to face a higher risk of infection and is more expensive.Metal intemal fixation has a series of defects such as easy to be electrolysed and eroded in vivo,stress-shielding,requiring re-operation to retrieve the internal fixation.For the destination of overcoming the disadvantages of methods mentioned above,scholars in the medical field and biomaterial science field have focus much energy on the preparation of an ideal biomaterial to replace bone graft and to repair bone defect.An ideal bone repair biomaterial should meet the demands as following:(1) no cytotoxicity;(2) no or low immunogenicity;(3) bioresorbable and could be totally replaced by newly born bone tissue in relative short time;(4) could undergo mechanical stress needed in the implanted area;(5) easy to prepare,preserve and purchase.Method:On the basis of the related literatures,a composite of PLGA was tested by a series of experiments in vitro and in vivo to observe its biocompatibility,osteoinductive and osteoconductive properties.The experiment was divided into four parts:1.Biological evaluation of PLGA composite.2.The assistant effect of PLGA on lumber interbody fusion of rabbits.Result:1.The results of experiments on acute toxicity pyrogen hemolysis implantation into muscles in rabbits met the demands of Technical Evaluation Standards of Biomedical Materials and Medical Instruments promulgated by Chinese Board of Health.2.The composite of PLGA prepared by emulsion blending methods showed satisfactory osteoinduction,osteoconduction and biocompatibility and could result in effective fusion of rabbit lumber interbody. Conclusions:1.PLGA has a good biocompatibility.2.The composite of PLGA showed satisfactory osteoinduction, osteoconduction and biocompatibility and could result in effective fusion of rabbit lumber interbody.