Different Porosities of Chitosan Can Influence the Osteogenic Differentiation Potential of Stem Cells

Scaffolds porosity has an important role in in vitro and in vivo differentiation process of stem cells with given the amount of space available to the cells to proliferate and differentiate. In the present study, chitosan with three porosities including 10%, 15%, and 20% that created by gelatin were used for investigation of the proliferation and osteogenic differentiation potential of adipose-derived stem cells (ADSCs). In order to be more like the scaffold to natural bone tissue, freeze-drying method was used in the scaffold preparation. Scaffold morphology, cell attachment, and toxicity were evaluated using scanning electron microscopy and MTT assay. Then, osteogenic differentiation potential of ADSCs cultured on chitosan with different porosities was evaluated by common osteogenic markers such as Alizarin red staining, ALP activity, calcium content, and osteogenic-related genes expression via real-time RT-PCR. Although all scaffolds supported the proliferation and differentiation of ADSCs, but 10% scaffold demonstrated higher amount of osteogenic markers in comparison with the other porosities and control groups. Taking together, it can be concluded that osteogenic differentiation well done in the scaffolds with lower porosity because density of the cells will increase by forcing resulted from the scaffold, so osteogenic differentiation of the stem cells have an inverse association with scaffold porosity. J. Cell. Biochem. 119: 625-633, 2018. © 2017 Wiley Periodicals, Inc.