Fig. 3
Chondrogenic induction ability of the dECM generated by hADSCs, hBMSCs, and hCDPCs. a. Experimental set up. To examine the chondrogenic induction ability of the dECM, undifferentiated hBMSCs were used as index cells and seeded atop the dECM derived from different cell sources. 1 × 105 hBMSCs (n = 3, pooled from three donors other than the matrix donor) grown in serum-free medium were seeded onto freeze-dried dECM. The attached BMSC–dECM constructs were then moved to new tubes and cultured in serum-free growth medium (DMEM-high glucose and ITS) without the addition of any other growth factors for 7 days, followed by q-PCR examination. b–e. The expression levels of chondrogenic/cartilage matrix-related genes (SOX9, COL2A1, AGN, CD44, HKG:18SrRNA, and RPL13a; Control: monolayer-cultured BMSCs). The experiment was repeated at least three times, with three technical replicates (cell–dECM constructs) for each trial. The mRNA extracted from each cell–dECM construct was examined with three technical replicates in the q-PCR assay. Data are presented as mean fold changes ± SD from a representative trial. A one-way ANOVA, followed by LSD, was used for statistical analysis, and p < 0.05 was considered statistically significant. Ctrl, monolayer cultures of index BMSCs; dA, index BMSCs seeded onto the hADSC–dECM; dB, index BMSCs seeded onto the hBMSC–dECM; dC, index BMSCs seeded onto the hCDPC–dECM. SOX9, SRY-box transcription factor 9; COL2A1, pro-alpha1(II) chain of type II collagen; AGN, aggrecan; CD44, cell surface glycoprotein, receptor of hyaluronic acid; 18SrRNA, 18S ribosomal RNA; RPL13a, ribosomal protein L13a. hADSCs, human adipose-derived stem cells; hBMSCs, human bone marrow-derived stem cells; hCDPCs, human cartilage-derived progenitor cells; ECM, extracellular matrix; dECM, decellularized ECM; q-PCR, quantitative polymerase chain reaction; DMEM, Dulbecco’s modified Eagle medium; ITS, insulin–transferrin–selenium; SD, standard deviation; ANOVA, analysis of variance; LSD, least significant difference. Figure 3a was created with BioRender.com by the authors with license obtained