Figure 4.

Collagen type 1 propeptide (C1CP) synthesised by human osteoblasts growing on electrodes and coverslips for one, three, and seven days. Peptide concentrations were determined from cell culture supernatant with and without electrical stimulation, and values are displayed relative to the unstimulated control for each time point. For this experiment, 0.2V, 1.4 V, and 2.8 V groups were stimulated 3 × 45 min per day, while the cont. 1.4 V group was stimulated continuously with 1.4 V. # indicates significant differences between the stimulated and control groups: # p < 0.05 and ## p < 0.01 (Wilcoxon matched pair test), * indicates significant differences between stimulation groups: ** p < 0.01 (two-way ANOVA). n ≥ 6.