Phthalocyanines for photodynamic therapy

In order to develop methods for controlling the photostability of phthalocyanines used in photodynamic therapy, the stability of their toluene solutions in presence of radical sources and air under white light was investigated. The results show that phthalocyanines photodecompose in the presence of alkenes or amino groups, and that their photodecomposition is strongly influenced by the nature of the radical source. Based on this study, four sets of silicon phthalocyanines bearing ligands which can act as radical sources or silicon phthalocyanines bearing ligands which can act as reference ligands were synthesized and characterized, and their photostability was studied. One set was composed of three alkoxysilicon phthalocyanines, the second of eight carboxysilicon phthalocyanines, another of a siloxysilicon phthalocyanine and the last of seven carboxylate salts of SiPc[OSi(CH3)2 (CH2)3NH(CH3)2]2. The members of the first set are SiPc[O(CH2)4CH3] 2, Pc 307, SiPc[OCH2CH=C(CH3)(CH2) 2CH=C(CH3)2]2, Pc 302 and SiPc[O(CH 2CH=C(CH3)CH2)2CH2CH=C(CH 3)2]2, Pc 303; of the second are SiPc[OC(O)(CH 2)16CH3]2, Pc 294, SiPc[OC(O)(CH 2)7CH=CH(CH2)7CH3]2, Pc 295, SiPc[OC(O)(CH2)6(CH2CH=CH)2(CH 2)4CH3]2, Pc 296, SiPc[OC(O)(CH 2)6(CH2CH=CH)3CH2CH 3]2, Pc 297, SiPc[OC(O)(CH2)2(CH 2CH=CH)4(CH2)4CH3] 2, Pc 299, SiPc[OC(O)CH2(CH2CH=CH)6CH 2CH3]2, Pc 300, SiPc[OC(O)(CH2) 3(CH2CH=CH)3(CH2)4CH3] 2, Pc 298 and SiPc[OC(O)(CH=C(CH3)CH=CH)2C 6H6(CH3)3]2, Pc 301; of the third is SiPc[OSi(CH=CH2)3]2, Pc 279; and of the last are of the type SiPc[OSi(CH3)2(CH 2)3NH(CH3)2]22+ [OC(O)R]-2 where the carboxylate anions are stearate, oleate, linoleate, linolenate, arachidonate, retinoate and docosahexaenoate. The results further show that the photodecomposition of phthalocyanines by radicals is strongly influenced by the nature of the radical source.;The penetration properties of a Pc 4-ethanol-propylene glycol formulation, of Pc 4-VanicreamRTM formulations with or without Tween RTM 80, and of Pc 4 salt-VanicreamRTM formulations with or without TweenRTM 80 through a model membrane (polydimethylsiloxane) were investigated with a Franz vertical diffusion cell system. An attempt to study the penetration properties of Pc 4 and Pc 4-salt formulations through pig keratomes also was made.;Four phthalocyanines designed to release their excited-state energy in a specific direction in space were synthesized and characterized. These were MPc[2,3- O(C2H4CH(CH3)CH2)2C 2H4CH(CH3)2]2 where M is H2, Ni, Co or Zn.;A better route was developed for the synthesis of the Pc 4 reference compound HOSiPcOSi(CH3)2(CH2)3N(C 2H5)2, Pc 34.;The Pc 12 naphthalocyanine analogue, SiNc[OSi(CH3)2(CH 2)3N(CH3)2]2, was synthesized and characterized.