Migration of DPSC-derived chondrogenic cells of cell pellets in collagen hydrogels. (A–F) DPSC-derived chondrogenic cells migrated into collagen hydrogels from cell pellets. (A, B) Cell migration in type I collagen hydrogel. (C, D) Cell migration in type II collagen hydrogel. Scale bar: 200 μm. (C) Magnified images of inset indicated in (B). (F) Magnified images of inset indicated in (E). Scale bar: 100 μm. (G) Quantification of cell migration distance in collagen hydrogels from cell pellets. *, p < 0.05, compared with cell migration in corresponding collagen hydrogels after cell culturing for 3 days. ^, p < 0.05, compared with cell migration in corresponding type II collagen hydrogels and crosslinked type I and type II collagen hydrogels after cell culturing for 3 days and 6 days. CL, crosslinked collagen.