Morphological regulation and aggregate formation of rabbit chondrocytes on dendrimer-immobilized surfaces with D-glucose display.

The present study describes dendrimer-immobilized surfaces with D-glucose display, used to regulate the morphology of rabbit chondrocytes by changing the generation number and density of the dendrimer, and to clarify the relation between cell morphology and chondrogenic expression on the prepared surfaces. When the generation number increased, the frequency of round-shaped cells increased, whereas, cell stretching was appreciably suppressed. Further suppression of stretching was significant on the G4-LD surface, on which the density of the immobilized dendrimer was lowered, and this phenomenon was thought to be responsible for the sparse display of D-glucose on the surface. The time-lapse observations revealed that the G4-LD surface caused repeated morphological changes of stretching and contracting, together with fluctuations in cell roundness. By the cytoskeletal staining of F-actin, the immature stress fibers were recognized in both round and stretched cells on the G4-LD surface. It was also found that N-cadherin expression was promoted on this surface, thus supporting the idea that an increase in cell-cell contacts may maintain chondrocytic phenotypes. These results suggest that a G4-LD surface can provide a culture environment to promote cell-cell interactions by N-cadherin-mediated adhesion during cell aggregation, thereby facilitating chondrocytic phenotypes of cells.