Osteogenic Differentiation of Mesenchymal Stem Cells Via Osteoblast- Imprinted Substrate: In Vitro and In Vivo Evaluation in Rat Model

Stem cells have great effects in clinical cell-based therapy. Accordingly, controlling the behavior and directing the fate of stem cells cultured in the laboratory is an important issue.

The aim of this study was to evaluate osteogenic properties of adipose derived mesenchymal stem cells (ADSCs) which differentiated toward osteogenic linage by osteoblast-imprinted substrate.

Rat ADSCs seeded on osteoblast-imprinted substrates, alkaline phosphatase (ALP) were measured in cellular supernatant of days 7 and 14. Alizarin Red staining of mineral matrix production in day 17 was performed. In order for in vivo evaluation, after seeding differentiated cells on a simple collagen scaffold, samples were implanted in an 8mm critical size calvarial defect. After 4 weeks defect site was harvested and prepared for histopathological examination.

ALP in both time points was significantly more than in undifferentiated ADSCs. (p<0.05). Alizarin red staining of differentiated cells showed a great production of mineral matrix nodules in cell culture plate. Histopathological investigations revealed greater amount of new bone formation and mostly in the center of defect, indicate osteoinductive effect of differentiated cells in vivo.

The osteoblast-imprinted substrate can mimic the topography and shape of natural osteoblast, which can mechanically direct ADSCs toward osteogenesis.