Study Of Physics Mechanism In Photodynamic Therapy: Relationship Between Surface Potential Of Mitochondrial Membrane And Cell Apoptosis

Photodynamic Therapy (PDT), as a new cancer treatment modality, has been employed in clinic use worldwide. In PDT, tumor is destroyed selectively, while other parts are not effected. Because of shortcomings of HpD, it is necessary to investigate more effective photosensitizers. Metal phthalocyanine used as photosensitizers is now concerned, which is regarded as a new kind to take the place of the first photosensitizers.The effects of Pc1, Pc2 and Pc3 on mitochondrial membrane potential and charge density in photodynamic therapy were investigated, and the conclusion was in accordance with results of MTT. Results show that effect of Pc1 was most prominent. That mitochondrial membrane is one of binding site of photosensitizers in PDT was suggested, and physics mechanism in PDT was discussed. Because of the close relationship of mitochondrial membrane potential and cell apoptosis, effect of photosensitizers on mitochondrial membrane potential proves an evidence for its efficiency.Fluorescence spectra of metal phthalocyanines were studied, meanwhile the effects of PDT on cell fluorescence spectra were investigated at the same time. Results suggest efficiency of Pc1.Last, the effects of photosensitizers on cell membrane fluidity were also studied in PDT, results showed. that cell membrane fluidity was reduced, suggesting cell membrane may be another binding site in PDT.Considering all the results stated above in discussing efficiency of metal phthalocyanines in PDT, we suggest that Pc1 is most effective.