(a) Molecular structure of Rho-Pt (used with permission of Kreatech Diagnostics) and cisplatin. (b) Dose-response functions of Rho-Pt and cisplatin treatment for 24 hr. Significant dose-dependent hair cell toxicity is demonstrated for both Rho-Pt (n = 6–11 fish) and cisplatin (n = 11–13 fish), (p< 0.001, one-way ANOVA), although Rho-Pt toxicity is significantly reduced compared to cisplatin (p<0.001, two-way ANOVA). (c) Hair cell survival for variable ratios of cisplatin:Rho-Pt (n=10 fish per group). Analysis of hair cell survival after treatment with variable ratios of cisplatin:Rho-Pt suggest that toxicity was additive, rather than synergistic or antagonistic, with a Chou-Talalay combination index of 1.09±0.15. Error bars = SD.