Photophysical and in vitro photocytotoxicity studies were performed for the photosensitizer Dimegine, a disodium salt 2.4-di(alpha-methoxyethyl)-deuteroporphyrin-IX with very low systemic toxicity. The singlet oxygen and luminescence quantum yield were Φ = 0,65 ± 0,06, and Φ=0,11 ± 0,01 respectively, and were independent of the excitation wavelength.
View Article and Find Full Text PDFCancer remains a major global malaise requiring the advent of new, efficient and low-cost treatments. Photodynamic therapy, which combines a photosensitizer and photons to produce cytotoxic reactive oxygen species, has been established as an effective cancer treatment but has yet to become mainstream. One of the main limitations has been the paucity of photosensitizers that are effective over a wide range of wavelengths, can exert their cytotoxic effects in hypoxia, are easily synthesized and produce few if any side effects.
View Article and Find Full Text PDFMetal-based photosensitizers are of interest as their absorption and chemical binding properties can be modified via the use of different ligands. Ru(2+) based photosensitizers are known to be effective photodynamic therapy (PDT) agents against bacteria, whereas use for oncological indications in vivo has not been demonstrated with the same level of evidence. We present data showing that premixing the Ru(2+)-complex TLD1433 with transferrin increases the molar extinction coefficient, including longer activation wavelengths, reduces photobleaching rates, and reduces the toxicity of the complex improving overall PDT efficacy.
View Article and Find Full Text PDFThe photo-physical and photo-biological properties of two small (<2 kDa), novel Ru(ii) photosensitizers (PSs) referred to as TLD1411 and TLD1433 are presented. Both PSs are highly water-soluble, provide only very limited luminescence emission at 580-680 nm following excitation at 530 nm, and demonstrate high photostability with less than 50% photobleaching at radiant exposures H = 275 J cm(-2) (530 nm irradiation). It was previously shown that these two photosensitizers exhibit a large singlet oxygen ((1)O2) quantum yield (Φ (Δ) ∼0.
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