Translator Disclaimer
1 June 1991 Efficacy of photodynamic killing with membrane associated and internalized photosensitizer molecules
Author Affiliations +
Proceedings Volume 1426, Optical Methods for Tumor Treatment and Early Diagnosis: Mechanisms and Techniques; (1991) https://doi.org/10.1117/12.44059
Event: Optics, Electro-Optics, and Laser Applications in Science and Engineering, 1991, Los Angeles, CA, United States
Abstract
Many photosensitizers under investigation for possible use in PDT share the property of selective accumulation in malignant or abnormal tissues. However, the mechanisms by which this occurs is not understood. Although it has been established that singlet oxygen is responsible for cell killing once a photosensitizer has reached the target tissue, the cellular targets and molecular mechanisms also remain unknown. The mechanisms of selective accumulation and cytotoxicity may depend upon the photosensitizer used. In attempts to develop technology to improve selective uptake by target tissues, the authors address the question of cellular targets at a preliminary level. These studies were performed using one benzoporphyrin derivative analogue, benzoporphyrin mono-acid ring A (BPD-MA). Plasma distribution of BPD-MA shows that this lipophilic photosensitizer has a propensity to associate with plasma lipoproteins in blood. Biodistribution studies indicate that preincubation of BPD-MA with low density lipoprotein (LDL) leads to significantly greater tumor accumulation than BPD-MA in aqueous solution. Further, the technology for conjugating BPD-MA to monoclonal antibodies has been established in the laboratory. Selective photodynamic killing of a human squamous cell carcinoma cell line (A549) has been demonstrated using such a conjugate. The monoclonal antibody (MoAb) used, 5E8, has specificity for a glycoprotein detected on human squamous cell carcinoma of the lung. In this study these two delivery systems are used to compare the cytotoxicity of membrane bound and internalized photosensitizer at the cellular level. The results indicate that LDL or MoAb mediated delivery increases the selectivity and cytotoxicity of BPD-MA. Internalization of BPD-MA via either delivery mode produces significantly enhanced cell killing.
© (1991) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Beth Allison, Frank N.J. Jiang, and Julia G. Levy "Efficacy of photodynamic killing with membrane associated and internalized photosensitizer molecules", Proc. SPIE 1426, Optical Methods for Tumor Treatment and Early Diagnosis: Mechanisms and Techniques, (1 June 1991); https://doi.org/10.1117/12.44059
PROCEEDINGS
8 PAGES


SHARE
Advertisement
Advertisement
Back to Top