Photocytotoxicity of liposomal zinc phthalocyanine in oral squamous cell carcinoma and pharyngeal carcinoma cells.

ABSTRACT

Aim: Photodynamic therapy utilizes a light-sensitive molecule that produces reactive oxygen species following irradiation. Photodynamic activities of free Zn phthalocyanine (ZnPc) and its liposomal formulations on human oral squamous cell carcinoma and pharyngeal carcinoma cells were assessed. Materials & methods: ZnPc was incorporated in extruded and nonextruded liposomes composed of palmitoyloleoylphosphatidylglycerol (POPG)palmitoyloleoylphosphatidylcholine (POPC) or POPGdioleoylphosphatidylethanolamine liposomes and incubated with CAL 27 or FaDu cells. Cell viability was assessed following illumination and further incubation. Results: ZnPc incorporated in extruded POPGPOPC liposomes caused extensive cytotoxicity, while ZnPc in extruded or nonextruded POPGdioleoylphosphatidylethanolamine liposomes or in multilamellar POPGPOPC liposomes were not effective. Conclusion: Extruded POPGPOPC liposomes are a useful delivery vehicle for ZnPc in photodynamic therapy of oral and pharyngeal cancers.