Fig. 4

Osteogenic protein level of fibroblasts treated with UHMWPE particles and added with macrophage supernatants. a Western blot, b ELISA. One asterisk indicates p < 0.05, two asterisks indicate p < 0.01, three asterisks indicate p < 0.001 versus A (fibroblasts only); one number sign indicates p < 0.05, two number signs indicate p < 0.01, three number sign indicate p < 0.001 versus B (fibroblasts + 1 mg/ml UHMWPE particles). One plus sign indicates p < 0.05, two plus signs indicate p < 0.01, ^three plus signs indicate p < 0.001 versus C1 (fibroblasts + 1 mg/ml UHMWPE particles + 1/16 macrophage supernatants vs. fibroblast media)