Effect of tantalum coating on adhesion, proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells / 中华创伤骨科杂志

ABSTRACT

Objective:To investigate the effects of tantalum coating on adhesion, proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) in vitro. Methods:In this study, BMSCs were extracted from 6 6-week-old rats and cultured in vitro to the third generation. Tantalum coating was manufactured on Ti6Al4V by chemical vapor deposition. The cells were identified by flow cytometry before they were induced with different mediums for osteogenesis, chondrogenesis and adipogenesis. The adhesion, proliferation and osteogenic differentiation of BMSCs were detected with fluorescence staining, Cell Counting Kit-8 (CCK8) assay and Q-PCR, respectively. Recorded and compared were the adhesion rate, proliferation rate, and expression of osterix (OSX), Runt-related transcription factor 2 (RUNX2), osteonectin (OSN) and osteopontin (OPN) of BMSCs on the surface of titanium alloy round plates (the Ti6Al4V group) and of tantalum coating round plates (the Ta group). Results:The flow cytometry revealed CD44 (94.55%), CD90 (95.01%) and CD34 (0.06%). Alkaline phosphatase (ALP) staining was positive after osteogenic induction for 14 days; Alizarin red staining showed calcified nodules after osteogenic induction for 21 days; oil red O staining was positive after adipogenic induction for 21 days; alcian blue staining found chondrogenic ability after chondrogenic induction for 21 days. Laser confocal microscopy showed that the BMSCs grew in patches aggregated and closely linked on the surface of titanium alloy round plates (in the Ti6Al4V group) and of tantalum coating round plates (in the Ta group). More BMSCs adhered on the tantalum coating plates than on the titanium alloy plates and exhibited better ductility. The proliferation rates of BMSCs on tantalum coating were significantly faster than those on titanium alloy after 1, 3, 5 and 7 days of co-culture in vitro ( P<0.05).Q-PCR showed that tantalum coating promoted the expression of OSN and OPN after 7 days of culture significantly higher than titanium alloy did ( P<0.05).After 21 days of co-culture in vitro, tantalum coating enhanced the expression of OSX, RUNX2, OSN and OPN significantly higher than titanium alloy did ( P<0.05). Conclusion:Compared to titanium alloy which is used for conventional orthopedic implants, tantalum coating can observably promote adhesion, proliferation and osteogenic differentiation of BMSCs.