Photodynamic therapy and anti-tumour immunity
Photodynamic therapy (PDT) uses non-toxic photosensitizers and harmless visible light in combination with oxygen to produce cytotoxic reactive oxygen species that kill malignant cells by apoptosis and/or necrosis, shut down the tumor microvasculature and stimulate the host immune system. In contrast to surgery, radiotherapy and chemotherapy that are mostly immunosuppressive, PDT causes acute inflammation, expression of heatshock proteins, invasion and infiltration of the tumor by leukocytes, and might increase the presentation of tumour-derived antigens to T cells.
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New light on medicine
Pigments that turn caustic on exposure to light can fight cancer, blindness and heart disease. Their light-induced toxicity may also help explain the origin of vampire tales.
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Inactivation of bacteria by Photodynamic Therapy
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