Comparative Assessment of Cartilage Quality in Human Induced Chondrocytes (hiCHOs) and Primary Articular Chondrocytes...

BackgroundCell-based cartilage repair is limited by loss of chondrogenic potential during in vitro expansion. Fibronectin (FN)-based selection may enrich progenitor-like cells with better matrix-forming ability, but its long-term effect on ECM production by hiPSC-derived chondroprogenitors (hiCPCs), their derived chondrocytes (hiCHOs), and primary articular chondrocytes (hACs) from lesioned or preserved areas remains unclear.MethodsWe here compared cartilage ECM formation by hiCPCs/hiCHO's and hACs, with or without FN selection, over extended passaging using 3D organoids. Histology and quantitative image analysis were performed to assess tissue quality across passages.ResultsChondrogenicity in hiCPCs transiently improved early-stage ECM production upon FN-based selection, but accelerated loss of chondrogenicity was seen in later passages. This was evidenced by diminished matrix staining and structural degradation from passage 4 onward. In contrast, hACs from both preserved and lesioned cartilage maintained stable matrix-forming ability across passages, independent of FN-based selection.ConclusionFN-based selection does not preserve long-term chondrogenicity in hiCHOs and may even impair it during extended culture. In contrast, primary cell sources, regardless of cartilage integrity, demonstrate greater and robust chondrogenic capacity without requiring progenitor enrichment. These findings highlight the intrinsic ability of hACs and question the utility of FN-based selection in cartilage tissue engineering.