Properties and Applications of Photodynamic Therapy

Abstract

Photodynamic therapy (PDT) is the treatment of malignant lesions with visible light following the systemic administration of a tumor-localizing photosensitizer. Pharmacological and photochemical properties of the photosensitizer are combined with precise delivery of laser-generated light to produce a treatment which can offer selective tumoricidal action. Hematoporphyrin derivative (HD) and a purified component called Photofrin II are currently being used in clinical PDT. Initial patient results have been encouraging, and considerable interest has developed in the synthesis and evaluation of new photosensitizers with improved photochemical and pharmacological characteristics. In addition, there has been a gradual increase in knowledge related to in vitro and in vivo mechanisms of action of PDT. This report provides an overview of the properties and applications of PDT. Information and data related to drug development, photochemistry, subcellular targets, in vivo responses, and clinical trials of PDT are presented.

Synergic effect of photodynamic therapy using talaporfin sodium with conventional anticancer chemotherapy for the treatment of bile duct carcinoma

“…[1][2][3][4][5][6][7][8] However, the anti-tumor effect was limited to the shallow bile duct wall because the 630 nm laser used in treatment had a low permeability. 10 Furthermore, the long period of skin photosensitivity required the patients to be kept away from strong sunlight for several weeks following the drug administration. 10 Therefore, we evaluated a new and effective photosensitizer, mono-L-aspartyl chlorin e6 (talaporfin sodium; NPe6, Laserphyrin ® ), which has been used for treating malignant tumors, such as bronchial cancer.…”

“…10 Furthermore, the long period of skin photosensitivity required the patients to be kept away from strong sunlight for several weeks following the drug administration. 10 Therefore, we evaluated a new and effective photosensitizer, mono-L-aspartyl chlorin e6 (talaporfin sodium; NPe6, Laserphyrin ® ), which has been used for treating malignant tumors, such as bronchial cancer. [11][12][13] The 664 nm semiconductor laser light activates talaporfin sodium and penetrates into deep tissue to a depth of more than 10 mm.…”

BPD-MA-mediated photosensitization in vitro and in vivo: cellular adhesion and β1 integrin expression in ovarian cancer cells

“…Investigations of cellular molecular responses to PDT reveal release of prostaglandin E 2 (PGE 2 ) (Henderson and Donovan, 1989), histamine release from mast cells (Glover et al, 1989), increased transcription and translation of some oxidative stress genes (Gomer et al, 1989) including haem oxygenase (Gomer et al, 1991), and the heat shock protein, Hsp70 (Gomer et al, 1988). More long-term effects, such as resistance to photosensitization (Singh et al, 1991;DiProspero et al, 1997) and mutation (Evans et al, 1989) could be the result of PDT-induced DNA single-strand breaks, sister chromatid exchanges or other chromosomal aberrations (Gomer et al, 1983).…”

Photodynamic apoptosis and antioxidant activities of Brassica napus extracts in U937 and SK-HEP-1 cells

“…This corresponds to a previous study reporting that the effects of photosensitizers depend on tissue distribution, affinity for certain cell types, penetration into various subcellular compartments, and accumulation [16]. Further, there was the difference between cells due to the various mechanisms involved in cell death [3,17,18]. The phototoxicity at 100 lg/ml of BNCE was higher than ADCL.…”

“…In PDT, photosensitizer injected into the body is selectively accumulated in tumor tissue and then activated by irradiating light of a particular wavelength, resulting in selective destruction of cancer cells. Currently, PDT has been clinically applied in cancer and general skin disease therapy [2,3]. But, it rarely causes cutaneous phototoxicity, and patients receiving photosensitizers are advised to stay away from direct sunlight and bright ambient light until the photosensitizer concentration in the skin tissues decreases to safe level to avoid cutaneous phototoxicity [4].…”