In adult articular cartilage, the pericellular matrix (PCM) mediates chondrocyte-matrix-interactions and is associated with the spatial cellular organization. Immunofluorescence microscopy, multiphoton-induced autofluorescence and second harmonic generation (SHG) imaging, as well as point pattern analyses revealed that both PCM and spatial organization were absent in fetal chondrocytes. In adult articular cartilage, the pericellular matrix mediates the biomechanical, biophysical and biomechanical interactions between the chondrocyte and the extracellular matrix. The PCM is also associated with the spatial organization of human superficial chondrocytes, which are situated in four distinct patterns of strings, clusters, pairs or single cells. However, little is known about the PCM and the spatial organization during fetal development. In this study, we asked the question whether fetal chondrocytes display a spatial organization comparable to that of adult chondrocytes, and whether a PCM is present or absent in the early stages of fetal cartilage development.Summary
Introduction