Fig. 1
Schematic diagram of stem cell-derived cell sheet and dECM sample preparation. a. Adult human adult stem/progenitor cells were isolated from adipose (hADSC, lipoaspirate, donors n = 3), bone marrow (hBMSC, hip joint replacement, donors n = 3), and articular cartilage tissue (hCDPC, knee joint replacement, donors n = 4) with Institutional Review Board approval. The cells were pooled and expanded to Passage 2. hADSCs, hBMSCs, and hCDPCs were seeded into 6-well plates (1 × 105 cells/well) and cultured in regular MSC–ECM induction medium (growth medium with 50 µM ascorbic acid) for 14 days to allow matrix deposition and cell sheet formation. b. The cell sheets were decellularized by treatment with Triton X-100, NH4OH, DNase, and RNase. The decellularized cell sheets were then freeze-dried using a lyophilizer and stored at 4 °C until further usage. The bottom right shows the morphology of freeze-dried decellularized cell sheets in 1.5-mL tubes for each group, and the arrow indicates the dECM derived from 1 × 105 hADSCs, hBMSCs, and hCDPCs (left to right). 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; MSC, mesenchymal stromal cell. The schematic diagrams were created with BioRender.com by the authors with license obtained