Figure 1. Effects of platelet-rich plasma and hyaluronic acid (HA+PRP) on cellular activity of primary chondrocytes obtained from osteoarthritic patients. (A) In vitro proliferation ability of chondrocytes was examined after two-day treatment of IL-1β+ TNF-α (I+T) conditioned medium in the presence of HA, PRP, and HA+PRP. (B) Assessment of cell viability on day 1, 3, 5, and 7 via MTT assay in HA, PRP, and HA+PRP treated chondrocytes. CTRL, control; I, IL-1β; T, TNF-α. *p<0.01, compared with the value in cells cultured in I+T using student t-test. The results are presented as mean ± S.D. for 15 independent experimental replicates.