The Effects Of Core-shell Electrospun Fibrous Scaffolds Loaded With BMP-2 On The Osteogenic Differentiation Of MC3T3-E1 Cells

Objective: Core-shell electrospun fibrous scaffolds loaded with BMP-2 were fabricated by coaxial-electrospinning.This study aimed to promote osteogenic differentiation of MC3T3-E1 cells by the synergistic effects of osteoconductive scaffolds and osteoinductive growth factors.Method: PLGA/PCL-BMP-2 core-shell nanofibrous composite scaffolds(PP-B)were fabricated by coaxial-electrospinning.Electrospun PLGA/PCL nanofibrous scaffolds(PP)were set as control group.The morphology and hydrophilicity of the two scaffolds were assessed using transmission electron microscope(TEM),scanning electron microscope(SEM)and Contact Angle Analyzer.In vitro releasing behavior of BMP-2 in PP-B scaffold was detected by ELISA.The extracts of PP-B scaffold were collected to culture MC3T3-E1 cells,and the alkaline phosphate(ALP)activity of the cells was evaluated.MC3T3-E1 cells were seeded on PP and PP-B scaffolds.The proliferation and osteogenic differentiation of MC3T3-E1 cells were evaluated by CCK-8 kit,the ALP activity assay,ALP staining and Alizarin red staining.Results: The TEM image confirmed that PP-B electrospun fibers fabricated by coaxialelectrospinning formed uniform core-shell structure.PP and PP-B fibers showed smooth and beads-free surface with uniform diameters in SEM images.Water Contact Angle test indicated the hydrophobic surface property of PP and PP-B scaffolds.The results of ELISA demonstrated the sustained release of BMP-2 in PP-B scaffold in vitro.BMP-2 remained active in PP-B scaffold.The data of CCK-8 were continually increased in both groups within 7 days.A higher level of ALP activity(P<0.05)and calcification were observed in PP-B group.Conclusion: PP-B fibers were confirmed with core-shell structure.BMP-2 in PP-B scaffold retained its bioactivity and released in a sustained way in vitro.There was no cytotoxicity in PP and PP-B scaffolds.PP-B scaffold improved the osteogenic differentiation of MC3T3-E1 cells in vitro.