Fabrication and evaluation of human dentin as scaffold for dental pulp stem cells

Scaffold is an important component of tissue engineering. Dentin is a potential material satisfying not only the physical and chemical characteristics of a standard scaffold, but also the inductive factors demand for dentin regeneration. Therefore, it is a promising material for tissue engineering. In this study, we aimed to create and characterize dentin scaffolds in order to serve as bioactive scaffolds for human dental pulp stem cells (hDPSCs) toward dentin-like tissue regeneration. Human dentin scaffolds were obtained from extracted teeth and irrigated in 17% ethylenediaminetetraacetic acid (EDTA) and 19% citric acid as chelate agents to remove smear layer. The treated scaffolds were examined morphology, the presence and secretion of dentin matrix protein, and in vitro cytotoxicity. The results demonstrated that 17% EDTA and 19% acid citric effectively removed smear layer. The presence of dentin matrix proteins, including transforming growth factor beta-1 and dentin matrix protein-1 were found to be secreted from human treated dentin scaffolds (hTDSs) during 5 days of investigation. hTDSs showed low level of cytotoxicity, which elicited a safe manner. Moreover, hTDSs provided a suitable surface for the attachment of hDPSCs, as well as supported their proliferation. When culturing hDPSCs onto the scaffolds, the formation of dentin-like tissue indicated their potential in directing differentiation of hDPSCs into dentin regeneration process, possibly, via bioactivity of the secreted dentin matrix proteins. Taken together, these data demonstrated that our proposed protocol was effective in generating hTDSs, and maintaining their compromising properties for application in regeneration of human dentin.