Photodynamic Therapy (PDT) is a minimally invasive procedure used for treating a range of neoplastic diseases, which utilises combined action of light and a PDT drug called a photosensitiser. The efficiency of this treatment depends crucially on the properties of the photosensitiser used, namely on its efficient uptake by cells or by the surrounding vasculature, intracellular localisation, minimal dark toxicity and substantial phototoxicity. In this report we compare the spectroscopic properties, cell uptake and in vitro phototoxicity of two novel hydrophilic photosensitisers derived from pyropheophorbide-a (PPa). Both new photosensitisers have the potential to form bioconjugates with antibody fragments for targeted PDT. We find that the photophysical properties of both new photosensitisers are favourable compared to the parent PPa, including enhanced absorption in the red spectral region and substantial singlet oxygen quantum yields. Both molecules show efficient cellular uptake, but display a different intracellular localisation. Both new photosensitisers exhibit no significant dark-toxicity at concentrations of up to 100 microM. The phototoxicity of the two photosensitisers is strikingly different, with one derivative being 13 times more efficient than the parent PPa and another derivative being 18 times less efficient in SKOV3 ovarian cancer cells. We investigate the reasons behind such drastic differences in phototoxicity using confocal fluorescence microscopy and conclude that intracellular localisation is a crucial factor in the photodynamic efficiency of pheophorbide derivatives. These studies highlight the underlying factors behind creating more potent photosensitisers through synthetic manipulation.
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http://dx.doi.org/10.1039/c0pp00038h | DOI Listing |
J Am Chem Soc
January 2025
Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States.
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Department of Urology, Jiangnan University Affiliated Hospital, Medical College of Jiangnan University, Wuxi 214125, China.
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Niemann-Pick disease (NPD) is an autosomal recessive disease caused by deficient lysosomal enzyme or faulty cholesterol transport. A 9-year-old male patient presented with 6 years of abdominal swelling, previously treated as tuberculosis. He exhibited hepatosplenomegaly, delayed growth, and pancytopenia.
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School of Chemistry and Materials Science, University of Science and Technology of China, Hefei 230026, China.
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View Article and Find Full Text PDFAnal Chem
January 2025
Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Analytical Chemistry for Living Biosystems, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
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