Using PLGA/α-TCP Composite Scaffold Incorporating VEGF Enhanced Osteogenic Differentiation of Rat Bone Mesenchymal Stem Cells

Objectives: The reconstruction of large bone defects has been the focus in bone tissue engineering research. By acting as synthetic frameworks for cell growth and tissue formation, biomaterials can play a critical role in bone tissue engineering. For treatment of large bone defects, bone grafting remains the method of choice for the majority of surgeons, as it fills spaces and provides support to enhance biological bone repair.
Methods: As therapeutic agents are desirable for enhancing bone healing, this studywas designed to develop such a bioactive composite scaffold (PLGA/α-TCP/VEGF) made of polylactide-co-gly-colide (PLGA) andα-tricalcium phosphate (α-TCP) as a basic carrier, incorporating VEGF as novel osteogenic exogenous growth factor. PLGA/α-TCP/VEGF scaffolds were fabricated as PLGA/α-TCP (control group) and PLGA/TCP in tandem with low/mid/high-dose VEGF(LV/MV/HV groups,respectively). To evaluate the in vivo osteogenic potentials of these bioactive scaffolds, we incubated with rat BMSCs under osteogenic inductive medium culture conditions, followed by the analysis of the mRNA levels of various osteogenesis-related genes, including ALP, Rux2, COL-I, and SP7, using a quantitative RT-PCR method.
Results: Following incubation of BMSCs with PLGA/α-TCP/VEGF scaffolds, cells reached confluency after 7 days. Additionally, the MTT analysis showed that PLGA/α-TCP/VEGF scaffolds had good biocompatibility with BMSCs,showing no significant inhibition of rat BMSCs proliferation. Furthermore, PLGA/α-TCP/VEGF scaffolds especially the PLGA/TCP/MV group, when incubated with rat BMSCs in the osteogenic culture medium, increased the mRNA levels of various osteogenesis-related genes. Finally, treatment of with PLGA/TCP/VEGF scaffolds potentiated calcium nodule formations after incubation with rat BMSCs in osteogenic culture medium for 21 days, as compared with non-VEGF control.
Conclusions: These findings may form a good foundation for potential vitro validation of this innovative bioactive PLGA/TCP/VEGF scaffold incorporated with the proper amount of VEGF.