Morphology and mechanics of chondroid cells from human adipose-derived Stem cells detected by atomic force microscopy

Chondroid cell from human adipose-derived stem cells (ADSCs) has emerged as an alternative treatment option for articular cartilage defects. Herein, we successfully compared ADSCs, normal chondrocytes, and chondroid cells. The comparative study of ADSCs and chondroid cells revealed type II collagen (COL II) and glycosaminoglycans expression of chondroid cells were similar to those in normal chondrocytes, and much higher than ADSCs. Using atomic force microscope (AFM) and laser confocal scanning microscopy (LCSM), we compared the differences in morphology, mechanical properties, and F-actin distribution between chondroid cells and normal chondrocytes. Our results showed no differences observed between these two types of cells regarding morphology, stiffness, and F-actin distribution. However, found that the adhesion force in chondroid cells was lower than that in normal chondrocytes. Taken together, our AFM and LCSM analyses suggest that the lower adhesion force in chondroid cells may contribute to the dedifferentiation of ADSC-derived chondroid cells. Future examination of surface adhesion force-related protein expression will likely provide new insight into the molecular mechanisms underlying the dedifferentiation of ADSC-derived chondroid cells.