Photodynamic therapy (PDT) is an emerging medical treatment that uses photosensitizers (drug) which are activated by
laser light for the generation of cytotoxic free radicals and singlet oxygen molecules that cause tumor cell death. In the
recent years, there has been a focus on using and improving an industrial colorant termed phthalocyanines as a
prospective photosensitizer because of its unique properties. This in vitro study investigated the photodynamic effect of
indium (InPcCl) and iron (FePcCl) phthalocyanine chlorides on human skin cancer cells (melanoma). Experimentally,
2 x 104 cells/ml were seeded in 24-well tissue culture plates and allowed to attach overnight, after which cells were
treated with different concentrations (2 μg/ml - 100 μg/ml) of InPcCl and FePcCl. After 2 h, cells were irradiated with
constant light doses of 2.5 J/cm2, 4.5 J/cm2 and 8.5 J/cm2 delivered from a diode laser. Post-irradiated cells were
incubated for 24 h before cell viability was measured using the MTT Assay. At 24 h after PDT, irradiation with a light
dose of 2.5 J/cm2 for each photosensitizing concentration of InPcCl and FePcCl produced a significant decrease in cell
viability, but when the treatment light dose was further increased to 4.5 J/cm2 and 8.5 J/cm2 the cell survival was less than 55% for photosensitizing concentrations of InPcCl and FePcCl from 4 μg/ml to 100 μg/ml. This PDT study
concludes that low concentrations on InPcCl and FePcCl activated with low level light doses can be used for the
effective in vitro killing of melanoma cancer cells.
Photodynamic therapy is a revolutionary treatment aimed at treating cancers without surgery or chemotherapy. It is
based on the discovery that certain chemicals known as photosensitizing agents (e.g. porphyrins, phthalocyanines, etc.)
can kill cancerous cells when exposed to low level laser light at a specific wavelength. The present study investigates
the cellular uptake and photodynamic effect of gallium (III) phthalocyanine chloride (GaPcCl) on Caco-2 cancer cells.
Caco-2 cells were treated with different concentrations of GaPcCl for 2 h before treatment with a diode laser
(λ = 661 nm, laser power = 90 mW) delivering a light dose of 2.5 J/cm2, 4.5 J/cm2 or 8.5 J/cm2. After 24 h, the cell
viability of post-irradiated cells was measured using the MTT assay. Cellular uptake studies were performed by
photosensitizing cells with GaPcCl for 30 min, 2 h, 10 h, 12 h, 18 h and 24 h before lysing the treated cells into solution
to measure the GaPcCl fluorescence emission at an excitation wavelength of 600 nm. Results showed an increase in
fluorescence intensity of emission peaks at longer incubation times, indicating a greater cellular uptake of GaPcCl by
Caco-2 cells at 24 h in comparison to 30 min. GaPcCl at a concentration of 100 μg/ml activated with a laser light dose
of 8.5 J/cm2 reduced the cell viability of Caco-2 cells to 27%. This concludes that GaPcCl activated with low level laser
light can be used as a photosensitizing agent for the in vitro PDT treatment of colon cancer.
Photodynamic therapy (PDT) represents a novel treatment that uses a photosensitizer (PS), light source (laser) of an
appropriate wavelength and oxygen to induce cell death in cancer cells. The aim of this study was to investigate the
photodynamic effects of aluminum tetrasulfophthalocyanines (AlTSPc) and zinc (ZnTSPc) tetrasulfophthalocyanines
activated with a 672nm wavelength laser on melanoma cancer, dermal fibroblast and epidermal keratinocyte cells. Each
cell line was photosensitized with either AlTSPc or ZnTSPc for 2 h before using a diode laser with a wavelength of
672nm to deliver a light dose of 4.5 J/cm2 to the cells. The cell viability of melanoma cells were decreased to
approximately 50% with concentrations of 40 μg/ml for AlTSPc and 50 μg/ml for ZnTSPc. These PS concentrations
caused a slight decrease in the cell viability of fibroblast and keratinocyte cells. Both photosensitizers in the presence of
high concentrations (60 μg/ml-100 μg/ml) showed cytotoxicity effects on melanoma cells in its inactive state. This was
not observed in fibroblast and keratinocyte cells. Cell death in PDT treated melanoma cells was induced by apoptosis.
Therefore, AlTSPc and ZnTSPc exhibit the potential to be used as a PS in PDT for the treatment of melanoma cancer.
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