Generation of periodontal ligament stem cells from human iPSCs with a chemically defined condition

Human periodontal ligament stem cells (PDLSCs) play an important role in periodontal tissue regeneration. The generation of PDLSCs from human induced pluripotent stem cells (iPSCs) by simulating the development pattern of PDLSCs in vivo provided a new way to obtain a large and stable source of PDLSCs. However, animal-derived components were still necessary for current differentiation protocols, which could cause safety and ethical problems and hinder the clinical application of iPSCs-derived PDLSCs. Here, we established a novel protocol to induce iPSCs into PDLSCs by chemically defined conditions. We first induced iPSCs into neural crest-like cells by inhibiting TGF-β pathway, BMP pathway and Notch pathway using SB431542, LDN and DAPT, respectively. The iPSC-induced neural crest-like cells were further cultured in chemically defined medium containing recombinant human bFGF as well as the rho-associated protein kinase inhibitor Y27632 to generate PDLSCs. The characteristics of iPSCs-derived PDLSCs and the bi-potentiality of osteogenesis and adipogenesis differentiation were verified in vitro. The establishment of the chemically defined differentiation system breaks through the limitation brought from animal-derived components and enables us to obtain a large number of PDLSCs, which holds a significant value to the research and treatment of periodontal diseases.