Figure 1

Representative microscopic images of fibroblast-like synovial cells post-lipopolysaccharide challenge. Representative microscopic images (400× magnification) of fibroblast-like synovial cells (a), (c), and (e) 2 hours post-lipopolysaccharide (LPS) challenge and (b), (d), and (f) 24 hours post-LPS challenge. Cells treated with the higher molecular weight hyaluronan (HA) product (group 4, pretreatment and sustained treatment with higher molecular weight HA) were protected from (d) and (e) the morphologic changes induced by LPS, including the loss of cell attachment to the culture flask and the pronounced cellular contraction that were seen in (a), (b) group 2 (LPS control) and (c), (d) group 3 (preteatment and sustained treatment with lower molecular weight HA).