Synthesis and Characterization of Functionalized Zinc Phthalocyanine-Natural Polymer Systems

New photosensitizers based on tetracarboxy- and octacarboxy- ZnPc derivatives conjugated to natural polymers for photodynamic therapy (PDT) are proposed. The tetracarboxy- and octacarboxy- ZnPc powders prepared by the direct condensation and hydrolysis were conjugated to chitosan (Ch). The ZnPc(COOH)4 and ZnPc(COOH)8 powders were solubilized in DMSO:H2O mixture solvent, ratio 1:1 and then self-assembled with degraded chitosan solution. The resulting ZnPc(COOH)4/Ch and ZnPc(COOH)8/Ch solutions were used for the investigation of the some photophysics properties. The UV-Vis spectra of both solutions show Q broad bands red shifted in comparison with unsubstituted of ZnPc in DMSO solution. At the excitation of the ZnPc(COOH)4/Ch with 643…702 nm a single band structure centered at 710 nm was revealed. For the (ZnPc(COOH)8/Ch, at the excitation with 363 nm and 707 nm the band centered only at 480 nm was observed. The fluorescence decay of (ZnPc(COOH)8/Ch shows 2.04 ns and 9.54 ns lifetimes of excited states, while for ZnPc(COOH)4/Ch indicates 2.77 ns.