Fig. 1

Biological characteristics identification of PDLSCs. A Cell morphology of primary periodontal ligament stem cells (PDLSCs). Scale bar = 200 μm. B Colony-forming assay stained by crystal violet. Scale bar = 200 μm. C Expression of cell surface markers CD31, CD34, CD45, CD90, CD146, and Stro-1 by flow cytometry. D (a) The alizarin red staining of PDLSCs after osteogenic induction for 0 days and 21 days. Scale bar = 200 μm. (b) The alcian blue staining of PDLSCs after cartilage induction for 28 days. Scale bar = 200 μm. (c) Oil red O staining of PDLSCs after adipogenic induction for 0 days and 28 days. Scale bar = 200 μm. E The CCK8 results of PDLSCs after stretching for 0, 6, 12, and 24 h. ****P < 0.0001