Photodynamic Therapy Effect on Immune Response

Photodynamic therapy (PDT) involves the use of non-toxic dyes or photosensitizers (PS) in combination with harmless visible light of the correct wavelength to excite the PS. In the presence of the oxygen, the excited state PS transfers energy or electrons to ground state molecular oxygen producing reactive oxygen species (ROS) such as singlet oxygen and hydroxyl radical that can kill cells. The singlet oxygen is the cytotoxic agent and that reacts rapidly with cellular components to cause the damage that ultimately leads to cell death and tumor destruction. The success of PDT depends on the photophysical and photochemical properties of the PS, its uptake and the exact subcellular location where this event occurs. The choice of wavelength depends on the PS used, because each PS has one or more specific wavelengths.Recent studies indicate that PDT could affect both the innate and adaptive arms of the immune system, which leads to the activation of the immune response. PDT has a significant effect on the immune system, both with immunostimulatory and immunosuppressive effects, being probably the determining factor related to the type of induced cell death. Immune stimulatory properties of PDT may increase its beneficial effects giving the therapy wider potential to become more extensively used in clinical practice.

کلیدواژه ها:

Photodynamic Therapy ، Reactive Oxygen Species ، Immunostimulator ، Immunosuppressive