Osteogenic Effect of Rabbit Periosteum-Derived Precursor Cells Co-Induced by Electric Stimulation and Adipose-Derived Stem Cells in a 3D Co-Culture System

Periosteum-derived progenitor cells (PDPCs) are highly promising cell sources for bone fracture healing because of their stem cell-like multipotency to undergo osteogenesis and chondrogenesis. Both externally physical stimulation and internally biochemical signal were reported to enhance osteogenic differentiation of bone tissues. Electric stimulation (ES) could trigger the differentiation of stem cells, like mesenchymal stem cells (MSCs) and adipose-derived stem cells (ADSCs). But the effect is still unclear on PDPCs. In order to investigate the differentiation ability of PDPCs co-induced by ES and ADSCs, a biomimetic 3-dimensional (3D) co-culture system was developed for providing ES and co-culturing with ADSCs. Gene expression was studied after a 3-day culture course. From our results, osteogenic differentiation of PDPCs was significantly activated under the ES of 0.7 V/cm, 80 kHz, and 3 hrs/day. Moreover, co-culturing with ADSCs during the ES treatment was found to have synergistic effect of osteogenic differentiation. In addition, chondrogenic differentiation was shown when the PDPCs were cultured for a long culture course. In summary, osteogenic differentiation of PDPCs was shown to be co-induced by ES and ADSCs. This study provides significant insights of the PDPC therapy for bone tissue regeneration.