Porphyrazine/phthalocyanine hybrid complexes – Antibacterial and anticancer photodynamic and sonodynamic activity

The activity of solitaire- and trans- zinc(II) porphyrazine/phthalocyanine hybrid complexes (1 and 2) as novel combinations for photodynamic and sonodynamic therapy were assessed against bacteria and cancer cells. In both manners, photostability, sonostability (1 MHz, 2 MHz, both 3 W) and singlet oxygen generation (with 1,3-diphenylisobenzofuran as a singlet oxygen chemical quencher) were measured. Hybrid complexes (1 and 2) were stable during irradiation and sonication. For photodynamic excitation manner the singlet oxygen quantum yields were calculated and were as follows 0.15 in DMF and 0.17 in DMSO for 1, and 0.1 in DMF and 0.18 in DMSO for 2. Sonodynamic manner revealed moderate generation of singlet oxygen by 2 upon 1 MHz, 3 W, while in 2 MHz, 3 W no generation was observed. Both hybrid complexes had high photodynamic antibacterial activity, reaching > 5 log reduction against both MRSA and Staphylococcus epidermidis, although their sonodynamic performance was negligible. Additionally, against squamous cell carcinoma (SCC-25) and hypopharyngeal tumor (FaDu) no photodynamic activity in vitro of 2 was observed, although the viability of reference MRC-5 fibroblasts was lowered. In sonodynamic manner 2 revealed slight activity against FaDu cells. Moreover, hybrid complex 2 revealed up to 38% inhibition of protease-activated protein C at 1 μM concentration, 52% inhibition of platelet-activated factor acetylhydrolase at 0.1 μM concentration and 29% inhibition at the concentration of 0.5 μM.