Figure 3.

Phototoxicity of PS adhered to microplates. To determine the phototoxic effect of PS adhered to microplates, three different incubation protocols were applied; PDT protocol A with cells being seeded after plates were preincubated with PSs; the standard PDT protocol B with cells being seeded prior to PS incubation, and protocol C with cells and PS being added to the plate concurrently. As photosensitizers 1.0 μM hypericin (a) or 5.0 μM hypericin (b); 1.0 μM PVP-hypericin (c) or 5.0 μM PVP-hypericin (d); 0.4 μM Foscan (e) or 2.0 μM Foscan (f) or 10 μM AlPCS₄ (g) and 50 μM AlPCS₄ (h) were employed. Cell viability was determined using the resazurin assay 24 h after illumination; results are shown relative to untreated controls. Abbreviations: Exp.: experiment; PS: photosensitizer.