Benzoporphyrin derivative and light-emitting diode for use in photodynamic therapy: applications of space light-emitting diode technology

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Publication Type Journal Article
School or College School of Medicine
Department Neurosurgery
Creator Schmidt, Meic H.
Other Author Whelan, Harry T.; Houle, John M.; Bajic, Dawn M.; Reichert II, Kenneth W.; Meyer, Glenn A.
Title Benzoporphyrin derivative and light-emitting diode for use in photodynamic therapy: applications of space light-emitting diode technology
Date 1998
Description Photodynamic therapy (PDT) is a cancer treatment modality that recently has been applied as adjuvant therapy for rain tumors. PDT consists of intravenously injecting a photosensitizer, which preferentially accumulates in tumor ells, into a patient and then activating the photosensitizer with a light source. This results in free radical generation ollowed by cell death. The development of more effective light sources for PDT of brain tumors has been facilitated by applications of space light-emitting diode array technology; thus permitting deeper tumor penetration of light and use of better photosensitizers. Currently, the most commonly used photosensitizer for brain tumor PDT is Photofrin®. Photofrin® is a heterogeneous mixture of compounds derived from hematoporphyrin. Photofrin® is ctivated with a 630 nm laser light and does destroy tumor cells in animal models and humans. However, treatment "ailure does occur using this method. Most investigators attribute this failure to the limited penetration of brain tissue by a 630 nm laser light and to the fact that Photofrin® has only a minor absorption peak at 630 nm, meaning that only a small fraction of the chemical is activated. Benzoporphyrin Derivative Monoacid Ring A (BPD) is a new, second generation photosensitizer that can potentially improve PDT for brain tumors. BPD has a major absorption peak at 690 nm, which gives it two distinct advantages over Photofrin®. First, longer wavelengths of light penetrate brain tissue more easily so that larger tumors could be treated, and second, the major absorption peak means that a larger fraction of the drug is activated upon exposure to light. In the first part of this project we have tudied the tumoricidal effects of BPD in vitro using 2A9 canine glioma and U373 human glioblastoma cell cultures. Using light emitting diodes (LED) with a peak emission of 688 nm as a light source, cell kill of up to 86 percent was measured in these cell lines by tumor DNA synthesis reduction. The effectiveness of BPD against tumor cells in vitro thus established, we have taken the first step toward determining its effectiveness in vivo. The second part of this project consisted of experiments performed to determine the maximum tolerated dose (MTD) of both BPD and LED light. At a light dose of 100 J/cm^2, skin damage and neurotoxicity were seen at a BPD dose of 1.0 mg/kg, but not at a dose of 0.75 mg/kg. When BPD remained constant at 0.75 mg/kg, skin damage was seen at light dosages of 125 J/cm^2, 150 J/cm^2 and 175 J/cm^2. One dog also died at a light dose of 175 J/cm^2. Further studies will be needed to determine the effectiveness of BPD against tumor cells in vivo.
Type Text
Publisher American Institute of Physics (AIP)
Volume 420
First Page 729
Last Page 735
DOI 10.1063/1.54943
citatation_issn 0094243X
Subject Benzoporphyrin; Photodynamic therapy; Brain tumors; Photofrin
Subject LCSH Photochemotherapy; Light emitting diodes; Gliomas; Brain -- Tumors -- Therapy
Language eng
Conference Title Space technology and applications international forum - 1998; Jan 1998; Albuquerque,New Mexico (USA)
Bibliographic Citation Whelan, H. T., Houle, J. M., Bajic, D. M., Schmidt, M. H., Reichert II, K. W., & Meyer, G. A. (1998). Benzoporphyrin derivative and light-emitting diode for use in photodynamic therapy: applications of space light-emitting diode technology. Space Technology and Applications International Forum, 420, 729-35.
Rights Management (c)American Institute of Physics. The following article appeared in Whelan, H. T., Houle, J. M., Bajic, D. M., Schmidt, M. H., Reichert II, K. W., & Meyer, G. A., Space Technology and Applications International Forum, 420, 1998, and may be found at http://dx.doi.org/10.1063/1.54943
Format Medium application/pdf
Format Extent 1,407,990 bytes
Identifier ir-main,12846
ARK ark:/87278/s6s760kz
Setname ir_uspace
Date Created 2012-06-13
Date Modified 2012-06-13
ID 704007
Reference URL https://collections.lib.utah.edu/ark:/87278/s6s760kz
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