Effects of media condition and CM or bi-layered co-culture on cartilage matrix production. After 21 days of culture with or without TGF-β3 supplementation, (A) DNA, (B) sGAG, and (C) collagen content per wet weight were evaluated. Data presented as mean±SD (n=3 samples/group). C, OACs; A, ADSC, CM, conditioned medium; Bi, bi-layered co-culture. * Represents significance versus−TGF-β control and ^ represents significance versus−CM control of the same cell type; +and # represent significance of the bi-layered co-culture group versus OAC and ADSC under the same media condition, respectively; *p<0.05, **p<0.01, and ***p<0.001. sGAG, sulfated glycosaminoglycan.