Preparation And In Vivo Study For Evaluating Biocompatibility And Osteogenesis Of BMP2and BMP7Gene Co-transfected BMSC/platelet-rich Plasma Gel Complex As Biomateirals In Tissue Engineering

Objective The purpose of this study is to establish an tissue engineering bone withautologous platelet-rich plasma (PRP) gel as scaffold,combined with rabbit bonemarrow mesenchymal stem cells (BMSCs) coexpressed with BMP2and BMP7,andprove it's good osteogenic capacity and bio-security in vivo,which can achieve therequirements of the interbody fusion materials and replace autologous bone and bone graftsubstitutes.Methods36New Zealand rabbits(two-month-old) were randomly divided into4groups of9. The first group implanted with PRP gel; the second group implanted withautologous platelet-rich plasma (PRP) gel combined with BMP2gene transfectedrabbit bone marrow mesenchymal stem cells (BMSCs); the third group implantedwith autologous platelet-rich plasma (PRP) gel combined with BMP2genetransfected rabbit bone marrow mesenchymal stem cells (BMSCs), the forth groupimplanted with autologous platelet-rich plasma (PRP) gel combined with BMP2,7gene co-transfected rabbit bone marrow mesenchymal stem cells (BMSCs).To obtain,isolate,culture and amplified rabbit bone marrow mesenchymal stem cells and check,select the third generation of cell to be transfected cells. To establish BMP2and BMP7adenovirus vector wiht pAd/CMV/V5-Dest as the carrier, and transfect the two genes into thethird generation of the rabbit BMSCs.5ml of whole blood was taken from ear central vein in each rabbit, PRP is prepared using theLendersberg method, and stored at-20℃.Mix and activate BMP2and BMP7co-transfected BMSCs and PRP, establish the tissueengineering bone with autologous platelet-rich plasma (PRP) gel combined withrabbit bone marrow mesenchymal stem cells (BMSCs) coexpressed with BMP2andBMP7,Part of which culture7days,then to observe the histological and morphological by scanning electron microscopy.Preparation of New Zealand rabbit lumbar defect model: drilling a single cortical bonedefect about2cm below the tibial plateau,the grind size is approximately3mm x5mmx7mm. Implant materials in the bone defect in accordance with the grouping.4,8and12week after surgery,we kill3rabbits in each group to observe changes in thetissue-engineered bone surface,callus formation,the repair of bone defect and surrounding tissuereaction. The remaining experimental animals were sacrificed16weeks after surgery,X-ray examination,CT scan, histological staining and electron microscopy are takento observe bone healing in each group.Results The tissue engineering bone we established with autologous platelet-richplasma (PRP) gel combined with rabbit bone marrow mesenchymal stem cells(BMSCs) coexpressed with BMP2and BMP7,can express genes and proteins related toosteogenesis adequately, without immunogenic,and has a good osteoinductive and osteogenesis invitro.It can express BMP2and BMP7stablely, and it has a better performance of boneinduction compared with untransfected group of BMP2and BMP7and other groups. Thetissue engineering materials we established can become the substitute to autologous bone andother bone graft materials.Conclusions1,Preparation of BMSCs by bone marrow adherent method was proper.The BMSCs obtained have multilineage differentiation potential.2,BMP2adenovirus and BMP2adenovirus vector in a pAd/CMV/V5-Dest could be transfected in rabbit BMSCs andco-expression of BMP2and BMP7.3,PRP prepared by Lendersberg method have goodhistocompatibility with BMP2, BMP7gene co-transfected BMSCs.4,BMP2, BMP7geneco-transfected group with better expression of osteoblast-related genes and proteins have betterosteoinductive activity and osteogenic capacity, compared with other groups.