Parallel testing of (a) cell vitality with MTT- and (b) membrane disruption with the LDH-assay at different time points (2 min, 15 min, 30 min, 2 h, 4 h, 24 h) and concentrations (LD₅₀: 1×, 2×, 4×) of [D]-K₃H₃L₉.

<p>The membrane integrity of the cells after incubation with [D]-K₃H₃L₉ at the LD₅₀ in 2 and 4 multiples showed a parabolic curve progression with over hundred percent LDH release after 24 h. The LDH release appears to rise faster than the cell viability decreases. These results indicate that the destruction of membrane integrity causes the decreased cell vitality after treatment with the peptide.