Cancer Therapy

Photodynamic Therapy

Tumor Targeted Photosensitizers

Long Wavelength Photosensitizers

Imaging & Therapy

PET / Fluorescence





Related Publications

Photosensitizers for PET / Fluorescence Imaging
with an Option of PDT

With the advancement in ‘‘non-invasive’’ imaging technologies and imaging probes, the field of imaging science is growing exponentially and therefore, fusion of in vivo imaging techniques. The imaging of specific molecular targets that are associated with cancer should allow for earlier diagnosis and better assessment of oncology patients. Porphyrins and most of the tumor-avid long-wavelength photosensitizers have very small wavelength differences between their near-infrared (NIR) absorption and emission bands (Stokes shifts). Such an inherent property limits application of these molecules for NIR tumor-imaging. The in vivo imaging is preferably performed in the NIR (700-900 nm) because of efficient optical tissue penetration and minimal auto-fluorescence in this spectral region. At NIR wavelengths, light penetrates several centimeters in tissue so that the fluorophore can be imaged deep within the body. By keeping these criteria in mind, our company synthesized PL-523 conjugate which has dual capabilityof photosense imaging and therapy.

Whole-body positron emission tomography (PET) is a diagnostic modality that can noninvasively survey the entire body and sensitively detect various cancers. Thus, PET imaging has the potential to detect cancers of many types at early stages with a single study. The approaches now focus on the development of a common molecule which is first used in low mass (as a radioactive material) to image and measure the target function, and then the mass of the molecule is increased by using the same unlabeled compound at therapeutic levels to treat the target function. The short half-life of 11C and 18F limits their use in studies involving monoclonal antibodies, and other molecules like photosensitizers (PS), which take a long time (hours instead of minutes) for accumulation in tumors. 124I is a more suitable candidate as it has a half-life of 4.2 days and is compatible with sequential imaging using microPET due to its longer biological half-life. Photolitec has developed PET-PDT bifuctional agent PL-531 that has shown promising potential as a tumor-imaging phototherapeutic agent. The photosensitizer also has shown promising tumor fluorescence and PET imaging ability.

PL agents clearly demonstrated that relatively selective accumulation on a tumor provides an opportunity to be utilized as a single agent for imaging (PET and optical) and therapy. The use of a single agent rules out any chances for variability in the pharmacokinetic and pharmacodynamic pattern of the drug at any stage.


Related Publications

Multimodality Agents for Tumor Imaging (PET, Fluorescence) and Photodynamic Therapy. A Possible “See and Treat” Approach
Suresh K. Pandey, Amy L. Gryshuk, Munawwar Sajjad, Xiang Zheng, Yihui Chen, Mohei M. Abouzeid, Janet Morgan, Ivan Charamisinau, Hani A. Nabi, Allan Oseroff, and Ravindra K. Pandey
Journal of Medicinal Chemistry, 2005, 48, 6286-6295
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In Vitro Cellular Uptake and Dimerization of Signal Transducer and Activator of Transcription-3 (STAT3) Identify the Photosensitizing and Imaging-Potential of Isomeric Photosensitizers Derived from Chlorophyll-a and Bacteriochlorophyll-a
Avinash Srivatsan, Yanfang Wang, Penny Joshi, Munawwar Sajjad, Yihui Chen, Chao Liu, Krishnakumar Thankppan, Joseph R. Missert, Erin Tracy, Janet Morgan, Nestor Rigual, Heinz Baumann, and Ravindra K. Pandey
Journal of Medicinal Chemistry, 2011, A-O
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Compared to Purpurinimides, the Pyropheophorbide Containing an Iodobenzyl Group Showed Enhanced PDT Efficacy and Tumor Imaging (124I-PET) Ability
Suresh K. Pandey, Munawwar Sajjad, Yihui Chen, Anupam Pandey, Joseph R. Misser, Carrie Batt, Rutao Yao, Hani A. Nabi, Allan R. Oseroff, and Ravindra K. Pandey
Bioconjugate Chem. 2009, 20, 274–282
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Comparative Positron-Emission Tomography (PET) Imaging and Phototherapeutic Potential of 124I- Labeled Methyl- 3-(1--iodobenzyloxyethyl)pyropheophorbide-a vs the Corresponding Glucose and Galactose Conjugates
Suresh K. Pandey, Munawwar Sajjad, Yihui Chen, Xiang Zheng, Rutao Yao, Joseph R. Missert, Carrie Batt, Hani A. Nabi, Allan R. Oseroff, and Ravindra K. Pandey
J. Med. Chem. 2009, 52, 445–455
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