Influence of VEGF/BMP-2 on the proliferation and osteogenetic differentiation of rat bone mesenchymal stem cells on PLGA/gelatin composite scaffold.

OBJECTIVE

To investigate the influence of VEGF/BMP-2 on the proliferation and osteogenic differentiation of rat bone mesenchymal stem cells BMSCs) on PLGA/gelatin composite scaffold.

MATERIALS AND METHODS

Randomly-oriented nanofibers with different ratios of Poly Lactic-co-Glycolic Acid (PLGA)/gelatin were produced through electrospinning. The mixture of nanofibers and BMSCs was pipetted onto the surface of the scaffolds, and BMSCs/PLGA/gelatin composite was obtained. The surface morphology, chemical structure, hydrophilicity and mechanical property of PLGA/gelatin nanofibers were revealed by scanning electron microscope. In vitro release kinetics of bone morphogenetic protein (BMP-2) and vascular endothelial growth factor (VEGF) were studied using ELISA kits. The cell adhesion, growth and proliferation of BMSCs on scaffolds were observed by scanning electron microscopy. The CCK-8 assay was used to evaluate the effects of VEGF/BMP-2 slow release system on the proliferation of BMSCs on scaffolds. RT-PCR was used to examine the activities of alkaline phosphatase (ALP), runt-related transcription factor 2 (RUNX-2), and osteocalcin (OCN).

RESULTS

In each group of cells in the in-vitro experiment, through electron microscope scanning, fiber scaffolds were interconnected three-dimensional reticular structure, BMSCs firmly attached to the fiber surface and internal stent, cells experienced a long spindle, polygon change, and branch-like protrusions on the cell surface were connected. Under the electron microscope, cell proliferation curve and osteogenesis markers (ALP, RUNX-2, OCN) expression in the dual factor group on cell adhesion, proliferation and differentiation were much better than those of blank control group and single factor groups.

CONCLUSIONS

In the successfully constructed gelatin/PLGA nanofiber scaffold, VEGF and BMP-2 can be sequentially released, during which VEGF and BMP-2 can promote the adhesion, proliferation, and differentiation of BMSCs.