Photodynamic therapy against achromic M6 melanocytes: phototoxicity of lipophilic axially substituted aluminum phthalocyanines and hexadecahalogenated zinc phthalocyanines

Abstract

Lipophilic and axially substituted tri-n-hexylsiloxy aluminum phthalocyanine and cholesteryloxy diphenylsiloxy aluminum phthalocyanine were synthesized and assayed in PDT against M6 melanocytes. In the conditions used ( > 480 nm, 10 mW cm À2 , egg-yolk lecithin or cremophor EL formulation) they both exhibited a higher photodynamic effect than chloroaluminum phthalocyanine. They displayed 2% to 3.5% cell viability at 10 À5 M dose for 20 min irradiation. Hexadecafluoro zinc phthalocyanine was synthesized to increase the lipophilicity of zinc phthalocyanine, hexadecachloro zinc phthalocyanine was also included because it would theoretically enhance the phototoxicity. In all the delivery systems used, their photodynamic effect against M6 melanocytes was lower in comparison with zinc phthalocyanine and axially substituted aluminum phthalocyanines. A 2 h irradiation treatment with 3 Â 10 À6 M hexadecafluoro zinc phthalocyanine and 10 À5 M hexadecachloro zinc phthalocyanine led to 60% and 15% cell viability respectively. In all cases, the cell killing effect was light-and dose-dependent and was higher in cremophor EL micelles than in the egg-yolk lecithin formulation.

Novel hydro- and lipo-philic selenium zinc(II) phthalocyanines: Synthesis, photophysical properties and photodynamic effects on CT26 colon carcinoma cells

“…The comparison of the IC 50 values, obtained from dose-response curves, revealed that 4 showed a higher potency than 5 ( Table 2). This is consistent with the conclusion that lipophilic photosensitizers are preferentially transported by lipoproteins, which are uptaken directly by tumor cells and favoring the cell killing efficacy in comparison with the hydrophilic one, as reported by Jori and co-workers [30][31][32].…”

Like a Bolt from the Blue: Phthalocyanines in Biomedical Optics

“…Decreau et al . [ 106 ] reported increasing phototoxicity with increasing the hydrophobicity of AlClPc derivatives. Indeed, when incorporated into liposomal (Egg Yolk Lecithin based liposomes) or emulsion (Cremophor EL based emulsion) formulations, the hydrophobic aluminium Pc (AlPc) derivatives such as 7 and its cholesterol derivative 8 ( Figure 5 ) were more phototoxic than 6 .…”

Propyl 4-(3,4-dicyanophenoxy)benzoate

“…Around 80 000 tons per year of phthalocyanines are produced to be used as dyes and pigments (Wö rhle, 2001). They are excellent pigments with good thermal and chemical stabilities and they have found wide applications in different fields, including liquid crystals, chemical sensors, photodynamic cancer therapy (Decreau et al, 2001), non-linear optics, molecular electronics, gas sensors, photosensitisers, catalysts, semiconductive materials, photovoltaic cells and electrochromic displays (McKeown, 1998;Leznoff & Lever, 1989-1996.…”