Increased osteogenic differentiation potential of MSCs cultured on nanofibrous structure through activation of Wnt/β-catenin signalling by inorganic polyphosphate.

There are several signal pathways involved in bone regeneration that can be triggered by several factors including mechanical, physical and chemical factors. Chemical growth factors are commonly used in differentiation induction to stem cells, while have side effects. In this study, inorganic poly-phosphate (poly-P) as a natural-based molecule was used to induce Wnt/β-catenin signalling in adipose-derived mesenchymal stem cells (AT-MSCs) while cultured on 2D and 3D culture systems. Common osteogenic markers were investigated to detect the influence of Wnt/β-catenin signalling induction on osteogenic differentiation of AT-MSCs and signalling genes up regulation was also evaluated by its related gene expression measurement. Results were shown that Cyclin-D1 and β-catenin gene expression was significantly increased in those cells treated by poly-P. Osteogenic differentiation of those stem cells with higher Cyclin-D1 and β-catenin gene expression was significantly higher than other groups except those stem cells cultured under osteogenic medium. According to the results, inorganic poly-P can trigger osteogenic differentiation in stem cells through Wnt/β-catenin signalling and this potential is almost close to common osteogenic growth factors and this could be used as natural-based molecules in bone regeneration, apart from concerns about the use of chemical factors.