The Osteogenic Differentiation of Mesenchymal Stem Cells Derived from Dental Pulp in Modular Alginate-Gelatin/Nano-Hydroxyapatite Microcapsules

Abstract Background Microcapsule is considered as a promising 3D microenvironment for Bone Tissue Engineering (BTE) applications. Microencapsulation of cells in an appropriate scaffold not only protects cells against excess stress but also promotes cell proliferation and differentiation. Methods In the current study, human Dental Pulp Stem Cells (hDPSCs) were cultivated in Alginate/Gelatin (Alg/Gel) and Alginate/Gelatin/nano-Hydroxyapatite (Alg/Gel/nHA) microcapsules. The proliferation and osteogenic differentiation of these cells were evaluated by MTT assay, qRT-PCR, Alkaline phosphatase, and Alizarine Red S.Results The results revealed that microencapsulation by Alg/Gel/nHA could improve cell proliferation and induce osteogenic differentiation. The cells cultured in the Alg/Gel and Alg/Gel/nHA microcapsules after 28 days showed 2.5-fold and 4-fold more activity of BMP-2 gene expression in comparison with the cells cultured on the polystyrene surface as a control group. The nHA addition to hDPSCs-laden Alg/Gel microcapsule could also up-regulate the bone-related gene expressions of osteocalcin, osteonectin, and RUNX-2 during a 28-day culture period. Calcium deposition and ALP activities of the cells were obsereved in accordance with the proliferation results as well as the gene expression analysis. Conclusion The study demonstrated that microencapsulation of hDPSCs inside Alg/Gel/nHA hydrogel can be a potential approach for regenerative dentistry in the near future.