RGD was the key peptide that allowed hDPSCs to bind with Npnt. (a) hDPSCs (passage number 5) were treated with KPRGDV (1 mM in PBS) (a, middle), KPRGEV (1 mM in PBS) (a, right), or equal volume of PBS (Control) (a, left) for 10 min and were then seeded onto Npnt (10 μg/mL)-coated substrate(s) (24-well plate) in serum-free DMEM, and media were changed into FBS (10%) containing DMEM after 19 h. Scrambled peptide (KPRGEV) did not inhibit cell adhesion (a, 19 h right). KPRGDV abrogated cell adhesion and spreading (a, 19 h middle). The abrogation was reversible when serum-free DMEM was replaced with 10% FBS containing DMEM (a, 43 h and 67 h) (scale bar: 400 μm). (b) Nucleus number determination in four separate fields under microscopy for each group. ∗p < 0.01 by post hoc Tukey' HSD test. (c) hDPSCs were first treated with PBS (c), KPRGDV (d), and KPRGEV (e) and subsequently seeded into Npnt-coated substrate(s) in serum-free DMEM for 24 h. Fluorescence staining was conducted to visualize actin stress fibers and nucleus. Well-development actin stress fibers were observed in (c) and (e), whereas cells remain round in (d) (scale bar: 100 μm).