Promoting osteogenic differentiation of human-induced pluripotent stem cells by releasing Wnt/β-catenin signaling activator from the nanofibers.

Implants that can enhance the stem cells differentiation in the absence of the chemical osteogenic growth factors will attract the great interest of orthopedic scientists. Inorganic polyphosphate (poly-P), as a ubiquitous biological polymer, is one of the factors that can be an alternative for osteogenic growth factors via activating Wnt/β-catenin signaling. In this study, poly-P was incorporated at the blend of polycaprolactone (PCL)/poly (l-lactic acid) (PLLA) electrospun nanofibers and then osteogenic differentiation potential of human-induced pluripotent stem cells (iPSCs) was investigated by the important bone markers. 3-[4, 5-dimethylthiazol-2-yl]-2, 5 diphenyl tetrazolium bromide (MTT) and scanning electron microscopy results confirmed the biocompatibility of the fabricated nanofibers, while higher proliferation rate of iPSCs was detected in PCL-PLLA(poly-P) group compared with the PCL-PLLA and tissue culture plate groups. Alkaline phosphatase activity, calcium content, and gene expression results demonstrated that osteogenic differentiation of iPSCs was increased when cultured on PCL-PLLA(poly-P) in comparison with other groups. According to the results, PCL-PLLA(poly-P) could be considered as a promising candidate for use as bone implants.