ABSTRACT
<p><b>OBJECTIVE</b>To isolate and cultivate human periodontal ligament stem cells (PDLSC) and to investigate the feasibility of PDLSC in vitro differentiation into chondrogenic phenotype.</p><p><b>METHODS</b>Periodontal tissue was obtained from healthy young human teeth extracted for orthodontic purposes. PDLSCs were isolated by single-colony selection and cultivated. PDLSC of passage 3 was plated at density of 1 x 10(7) cells/cm3 and induced with chondrogenic induction medium of DMEM containing TGF-beta1 (10 microg/L), IGF-1 (50 microg/L), dexamethasone (40 microg/L) and 10% FBS. In control group, the constructs were maintained in DMEM medium + 10% FBS. After 21 days induction, the results were evaluated by histology, histochemistry, immunohistochemistry and RT-PCR.</p><p><b>RESULTS</b>The constructs in experimental group were smooth and relatively firm in texture after 3 weeks of culture. Toluidine blue staining showed the formation of distinct lacuna structure. Positive staining of type II collagen was also detected by immunohistochemistry and it was confirmed by RT-PCR. In contrast, in the control group, the constructs collapsed gradually, lacuna was barely detected in histology and type II collagen expression negative.</p><p><b>CONCLUSIONS</b>Periodontal ligament contain stem cells can be isolated and cultivated. PDLSC have the potential of chondrogenic differentiation.</p>