Solubility of (aza)phthalocyanines ((Aza)Pc) in water is very limited due to their flat aromatic core that makes them prone to aggregation. Stacking of (Aza)Pc cores (forming dimers or higher-order aggregates) leads to quenching of their excited states - fluorescence and 1O2 production [1].
Several approaches to improve the solubility have been described, but truly non aggregating water-soluble (Aza)Pcs are still scarce [2-7]. Here we present a series of novel water-soluble hydrophilic and amphiphilic zinc (Aza)Pcs with differently charged (cationic and anionic) as well as non-charged peripheral substituents.
These compounds were directly compared to several clinically approved photosensitizers (PSs; verteporfin, temoporfin, Photosens, methylene blue and protoporphyrin IX - a photodynamically active product of a prodrug 5-aminolevulinic acid).