The Research Of The Effect Of PLGA/CPC Polymer Carrying Simvastatin On The Osteoblasts

In order to prevent the absorption and atrophy of the residual alveolarridge, the research was mainly concentrated on such methods as autografts,allografts, the guided bone regeneration technique and immediate dentalimplants, but these methods can cause secondary lesions or immunologicrejection and so on,which limited their clinical applications. Gene therapy isalso the research focus in the recent years, BMP is the main protein which playsthe function bone, has been widely used in stimulating bone regeneration.Because the concentration of necessary BMP promote bone formation istremendous,and gene expression and purification of restructuring BMP isdifficult, so the clinical application is limited. When it was found thatsimvastatin drugs can induce the osteoblast and marrow stromal stem cellsBMP2expression, using drugs the prevention and treatment of alveolar spineatrophy become the research focus. And to find a suitable simvastatin drugcarrier is also very important.In view of the problem about the insufficient strength of the carrier and theacid production after degradation, we will try to prepare the composite scaffoldmaterial--polylactic acid polyglycolic acid (PLGA)/calcium phosphate bonecement (CPC) as the carrier of simvastatin by solvent volatilixation method andchemosynthesis method from the aspect of bionics, basing on the accompli-shment of the experimental study of the effect of simvastatin carried by PLGAon the bone restoration of residual alveolar ridge. And we have prepared thescaffold material and carried animal experiments of the scaffold materials，thisexperiment will research in the PLGA/CPC scaffold materials carryingsimvastatin to the mechanism of osteoblast in vitro. First,prepare the composite scaffold material--PLGA/CPC as the carrier ofsimvastatin by solvent volatilixation method, Take three parallel PLGA/CPC/simvastatin specimens after uv disinfection into the PBS solution according tothe standard leaching method in the aseptic conditions, In3d we will take outall of the liquid, the leaching solution of the material was made. Made theconcentration of leaching solution dilution, to achieve the concentration of the10-7M, The control group was also diluted the same multiples. Then, theleaching solution of PLGA/CPC materials with or without simvastatin andosteoblasts were cocultured in vitro; The results of Cell proliferation showedthat as time goes on, the same group of cell number has increased, in the day of3,5,7, the experimental groups compared with control groups couldsignificantly promote osteoblast proliferation, Difference was statisticallysignificant (P <0.05),the conclusion shows that the scaffold materials withsimvastatin in the appropriate concentration can promote the osteoblastproliferation compared with controls. The associated mRNAs (Runx2, Osx,Ocn) during osteoblast differentiation were detected by semiquantitativeRT-PCR on the5th day. The mRNAs of Runx2, Osx and Ocn were promotedon day5. Osteoblast function was evaluated by the measurements of ALPactivity and Coomassie brilliant blue. The ALP activity and the content ofprotein were higher on the day3、5and7(P＜0.01). The above conclusionsshow that the scaffold materials with simvastatin in the appropriate concentr-ation can promote the osteoblast differentiation compared with controls.The innovation of this study is the first preparation the leaching solutionof the material, The effect of leaching solution of PLGA/CPC polymer carryingsimvastatin on the proliferation and differentiation of osteoblasts was evaluatedby MTT assay、Coomassie brilliant blue、the measurements of ALP activity and semiquantitative RT-PCR., which provides the oretical basis and exper-imental basis for further clinical application.