Differentiation Effect of Exosomes Derived from Monocytes and Macrophages on Chitosan Alginate Drip Scaffolds

Bone injuries are one of the challenges of medical science which costs a lot of money in the world for the treatment every year. Exosomes are nanovesicles which carry the proteins and genetic material into the target cell, which in turn, induces the proliferation, cell survival, and differentiation in the recipient cell. These features make exosomes a proper differentiation factor. This study aimed to investigate the differentiating effect of exosomes derived from the monocytes and macrophages on chitosan alginate drip scaffolds. Chitosan-alginate scaffolds were made by drip method with fat stem cells. Monocytes were cultured, and the supernatant was collected, and the exosomes were collected by the ultracentrifugation. Exosomes were identified by DLS and SEM methods. The samples were treated, and then MTT and DAPI tests were performed. The osteogenic differentiation was examined by alkaline phosphatase and real-time PCR. MTT results showed that the survival rate of differentiated cells with exosomes on days 7, 14, and 21 was increased compared to control group. Moreover, DAPI results showed no cell death in the treatment groups, and the results of the alkaline phosphatase test showed an increase with the control group, and also the results of real-time PCR increased the expression of genes BMP2/6, SMAD4 and differentiation genes Osc and Opn in the treatment group. This study showed that the exosomes derived from the monocytes and macrophages could cause survival and osteogenic differentiation of the fat mesenchymal cells in the chitosan alginate scaffold.