Background and Objective: Photodynamic therapy is a treatment that uses photosensitizer and intense visible light. When photosensitizers get exposed to a specific light wavelength (preferentially in the red region), they produce reactive oxygen species that are toxic to cells. Recently, attention has been focused on porphyrins and their analogs as photosensitizers. Zn (II) tetrapyridinoporphyrazin complex is a water-soluble photosensitizer that has a good potential for application in photodynamic therapy. In this study, phototoxic effect of this complex on HeLa cancer cell line has been investigated. Materials and Methods: HeLa cell cultures were treated with different concentrations of Zn (II) tetrapyridinoporphyrazin. The cytotoxic effects were measured both in the presence and absence of light using the MTT assay. The light source was a 150W tungsten halogen lamp equipped with a red filter. Results: Our data indicate that porphyrazine’s photocytotoxicity is remarkably more significant than its cytotoxycity in the dark. Statistical analysis showed the effective dose (ED50) values in the dark and light conditions were 8.6 and 4.2 µM, respectively. In addition, the results imply that in the range of 0-12 µM, the increase in the complex concentration correlates with the increase in the cytotoxicity effect. However, the cytotoxicity decreases at the higher concentration (50µM), which is likely due to aggregation of the complex. Conclusion: Our results show that Zn (II) tetrapyridinoporphyrazin complex may be a promising photosensitizer for innovative photodynamic therapy and may have a high potential application in cancer treatment. Furthermore, it seems to have more benefits compared to other known photosensitizers.

Background and Objective: Photodynamic therapy is a new therapeutic modality for the treatment of cancer. Photodynamic therapy uses an inactive drug and a light source to activate the drug to produce reactive oxygen species that destroy the cancer cells. In the present study, the effect of two different laser light sources on the efficiency of photodynamic therapy was evaluated using a breast cancer cell line.

Materials and Methods: MDA-MB-231cells were grown on 96-well plates. After the treatment with different concentrations of 5-aminolevulinic acid, cells were irradiated with a light dose of 10 and/ or 20 Jcm^-2 by two different laser light sources. Cell viability was measured by MTT assay.

Results: Results showed that 5-aminolevulinic acid at concentrations of 0.5, 1 and 2 mM had no significant cytotoxic effect on the breast cancer cells in the absence of laser activation. However, the treatment of cells with 5-aminolevulinic acid and light dose of 20 Jcm^-2 using Lasotronic laser and Mustang laser, decreased cell viability of the breast cancer cells to 80% and 65%, respectively.

Conclusion: Light source used in photodynamic therapy plays an important role in the efficiency of this therapeutic modality and light activation of 5-aminolevulinic acid at a photosensitizing concentration using a proper laser light source may potentially be lethal for breast cancer cells.

Backgrounds and Objective: Titanium dioxide (TiO₂) is a potent photosensitizer in photodynamic therapy (PDT) and is activated upon ultraviolet (UV) irradiation.The aim of this study was the assessment of the effect of nitrogen –nano doped of titanium dioxide in human A-375 melanoma cancer cell line.

Materials and Methods: N-TiO₂ nanoparticles were prepared by mechanical mixing of urea with TiO₂ powder in a 4:1 weight ratio. A-375 cells were treated with different concentrations of N-TiO₂ for various time intervals in the presence or absence of visible light. The growth and viability of A-375 cells were determined by means of trypan blue exclusion test and MTT assay, respectively. Acridine orange/Ethidium bromide double staining and DNA gel electrophoresis were applied to determine apoptosis.

Results: The results showed that visible light activated N-TiO₂ could induce growth inhibition in a dose (0.01-100 μg/ml ) and time dependent manner. In concentration of 0.5 μg/ml a significant difference was observed between the treated and the control samples.Decrease in viability was observed in 100 μg/ml concentration and the results of fluorescent microscopy showed  DNA fragmentation due to apoptotic cell death[G1]  at this concentration.

Conclusion: Based on the anti-cancer effects of N-TiO₂ on A-375 cells, further evaluation of these nanoparticles as a new photosensitizer in photocatalytic therapy of skin cancer can be proposed.

Background and Objective: The treatment of cancer comes as a great challenge worldwide. Thus the development of effective therapies with minimal side effects is important. Photodynamic therapy is a non-invasive and new therapeutic approach for the treatment of cancer. Therefore, in this study, we evaluated the photodynamic effects of a light-sensitive compound, Zinc-phthalocyanine (ZnPc), on cell growth and the expression of caspase-9 in SW872 cell line.
Materials and Methods: For cytotoxic effects of photodynamic therapy with ZnPc, MTT assay was conducted. Quantifying the level of caspase-9 gene expression was carried out with qRT-PCR. The statistical analysis was done by GraphPad Prism 6 software.
Results: MTT assay results showed that photodynamic therapy with ZnPc significantly reduced cancer cell growth. The IC50 for cell line SW872 was 0/034 μg/ml in a 24 J/cm2 light source. qRT-PCR results showed that photodynamic therapy with ZnPc increased the gene expression of caspase-9 in the treated group.
Conclusion: Photodynamic therapy with ZnPc resulted in decreased cell growth and induced apoptosis in a concentration-dependent manner in SW872 cell lines. Based on the results, photodynamic therapy with ZnPc can be a powerful therapeutic approach for the treatment of skin cancer with minimal side effects.