Paper
2 April 1996 Photodynamic therapy (PDT) as a biological modifier
Modestus Obochi, Jing-Song Tao, David W. C. Hunt, Julia G. Levy
Author Affiliations +
Abstract
The capacity of photosensitizers and light to ablate cancerous tissues and unwanted neovasculature constitutes the classical application of photodynamic therapy (PDT). Cell death results from either necrotic or apoptotic processes. The use of photosensitizers and light at doses which do not cause death has been found to affect changes in certain cell populations which profoundly effect their expression of cell surface molecules and secretion of cytokines, thereby altering the functional attributes of the treated cells. Cells of the immune system and the skin may be sensitive to modulation by 'sub-lethal PDT.' Ongoing studies have been conducted to assess, at the molecular level, changes in both lymphocytes and epidermal cells (EC) caused by treatment with low levels of benzoporphyrin derivative monoacid ring A (BPD) (a photosensitizer currently in clinical trials for cancer, psoriasis, endometriosis and age-related macular degeneration) and light. Treatment of skin with BPD and light, at levels which significantly enhanced the length of murine skin allograft acceptance, have been found to down-regulate the expression of Langerhans cell (LC) surface antigen molecules [major histocompatibility complex (MHC) class II and intracellular adhesion molecule (ICAM)-1] and the formation of some cytokines (tumor necrosis factor-alpha (TNF- (alpha) ).
© (1996) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Modestus Obochi, Jing-Song Tao, David W. C. Hunt, and Julia G. Levy "Photodynamic therapy (PDT) as a biological modifier", Proc. SPIE 2675, Optical Methods for Tumor Treatment and Detection: Mechanisms and Techniques in Photodynamic Therapy V, (2 April 1996); https://doi.org/10.1117/12.237528
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Cited by 1 scholarly publication.
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KEYWORDS
Photodynamic therapy

Skin

Control systems

Molecules

Tissues

Modulation

Cell death

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