Characterization of cartilage pellets engineered from periodontal ligament stromal cells

Abstract

Objectives: The purpose of this study is to investigate the potential of periodontal ligament stromal cells (PDLSCs) to differentiate into the cartilaginous lineage and to characterize the tissue engineered cartilage at the molecular level.Materials and methods: Cells were obtained from the periodontal ligament (PDL) tissues of premolar teeth of 5 orthodontic patients (15 to 40 years of age, average 26.6 years old). In vitro chondrogenesis was induced by culturing PDLSCs into micropellets with chondrogenic media containing 10 ng/ml of TGF-β1 for 3, 7, 14, and 21 days. Morphological characterization of the pellets was accomplished by H-E and alcian blue staining, TEM analysis and immunohistochemical staining for type II collagen. A real-time quantitative polymerase chain reaction (RT-qPCR) was then performed to analyze the mRNA expression of the chondrogenic differentiation related markers such as sox9, type I and II collagen, aggrecan, BMP4 and BSP.Results: Chondrocytic cell morphology and specific features like lacunae were observed in H-E staining. The production of proteoglycan and type II collagen increased gradually but the viability of the chondrogenetic cells seemed to be worsened as chondrogenesis proceeded. The results of RT-qPCR showed that the mRNA level of type I collagen was maintained, however, those of the other investigated markers were gradually upregulated, reaching their peaks at day 21. Conclusion: This study confirms that PDLSCs, an easily obtainable stromal cell source from the oral environment, can differentiate into cartilaginous pellets in vitro. Therefore, PDLSCs could be a promising cell source for cartilage graft material which can be used for the repair or reconstruction of damaged cartilage tissues.

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