A Composite Scaffold Released Simultaneously BMP2 And BMP7 For Application In Bone Tissue Engineering

Objective: In this study,we designed a novel bioactivity scaffold,which can simultaneously release BMP2 and BMP7,for osteogenic differentiation of stem cell in bone tissue engineering.Methods: BMP2 and BMP7 microspheres(namely B2 MS and B7MS)were firstly prepared using a emulsion method.And the 3D-PLGA porous scaffolds(namely PSCs)were also produced by phase separation.To form the BMP2-PLGA composite scaffold(B2MS-PSC)and BMP7-PLGA composite scaffold(B7MS-PSC),the B2 MSs and B7 MSs were fixed into PSCs with methylene chloride fumigation technology,for investigation of slow-release effect of BMP2 and BMP7.The Human bone marrow stromal cells(namely hBMSCs)were seeded into these BMP2-PLGA composite scaffolds for various tests,including cell adhesion,proliferation and osteogenic differentiation.Results: 1.The BMPs-PLGA composite scaffolds with BMP2 and BMP7(B2B7MS-PSCs)were successfully prepared.The ALP of B2B7MS-PSCs was higher than the scaffold without BMPs on day 3(P<0.05);and more than that of B2MS-PSC and B7MS-PSC on day 6(P<0.01).2.B2B7MS-PSCs showed good cell adhesion,and most cells as groups adhered in inner space of 3D-porous structure.These cells do inter-connection and some pseudopods were found,and the advantages of B2B7MS-PSCs were hold on up to 9th day.3.The proliferation of B2B7MS-PSCs was higher than others(P<0.01)after 6th day.4.On day 9,the expressions of collagen type-1(COL-1),osteocalcin(OCN),osteoprotegerin(OPG)and osteopontin(OPN)of B2B7MS-PSC was higher than B2MS-PSC and B7MS-PSC.(P<0.05)Conclusion:1.The bioactivity scaffold,B2B7MS-PSC,released simultaneously BMP2 and BMP7 has been prepared in this study.2.B2B7MS-PSC can induce hBMSC to osteogenesis.Cell proliferation and osteogenesis ability of B2B7MS-PSC is better than scaffolds with single BMP2 or BMP7.