Search results for "Photosensitizing Agent"
showing 7 items of 67 documents
Pyrrolo[2,3-h]quinolinones: A new ring system with potent photoantiproliferative activity
2006
A new class of compounds, the pyrrolo[2,3-h]quinolin-2-ones, nitrogen isosters of the angular furocoumarin Angelicin, was synthesized with the aim of obtaining new photochemotherapeutic agents with increased antiproliferative activity and lower undesired toxic effects than the lead compound. Two synthetic pathways were approached to allow the isolation both of the dihydroderivatives 10-17 and of the aromatic ring system 23. Compounds 10-17 showed a remarkable phototoxicity and a great UVA dose dependence reaching IC(50) values at submicromolar level. Intracellular localization of these compounds has been evaluated by means of fluorescence microscopy using tetramethylrhodamine methyl ester a…
Photosensitization of DNA by β-carbolines: Kinetic analysis and photoproduct characterization
2012
β-Carbolines (βCs) are a group of alkaloids present in many plants and animals. It has been suggested that these alkaloids participate in a variety of significant photosensitized processes. Despite their well-established natural occurrence, the main biological role of these alkaloids and the mechanisms involved are, to date, poorly understood. In the present work, we examined the capability of three important βCs (norharmane, harmane and harmine) and two of its derivatives (N-methyl-norharmane and N-methyl-harmane) to induce DNA damage upon UV-A excitation, correlating the type and extent of the damage with the photophysical characteristics and DNA binding properties of the compounds. The r…
Bactericidal efficiency of porphyrin systems
2021
Photodynamic Inactivation is an innovative technique used to combat bacterial and viral infections which involves the use of photosensitizing agents along with light to generate cytotoxic reactive oxygen species able to kill bacteria and viruses. In the first section of this minireview, porphyrin-based fluorophores are shown to be remarkable dye candidates for PDI (photodynamic inactivation) applications. The second section is dedicated to the description of porphyrin-based antimicrobial materials and their potentialities for industrial applications such as in food packaging or antimicrobial medical devices and hygiene. Finally, the failings and perspectives of PDI are analyzed to demonstr…
Synergistic Anticancer Therapy by Ovalbumin Encapsulation-Enabled Tandem Reactive Oxygen Species Generation
2020
Abstract The anticancer efficacy of photodynamic therapy (PDT) is limited due to the hypoxic features of solid tumors. We report synergistic PDT/chemotherapy with integrated tandem Fenton reactions mediated by ovalbumin encapsulation for improved in vivo anticancer therapy via an enhanced reactive oxygen species (ROS) generation mechanism. O2 .− produced by the PDT is converted to H2O2 by superoxide dismutase, followed by the transformation of H2O2 to the highly toxic .OH via Fenton reactions by Fe2+ originating from the dissolution of co‐loaded Fe3O4 nanoparticles. The PDT process further facilitates the endosomal/lysosomal escape of the active agents and enhances their intracellular deliv…
Feasibility and Diagnostic Impact of Fluorescence-Based Diagnostic Laparoscopy in Hepatocellular Carcinoma: A Case Report
2002
Fluorescence-based diagnostic techniques are an evolving field in the staging of hepatologic and gastroenterologic malignancies. The method aims at improved accuracy in the detection of locoregional and distant metastases. In hepatocellular carcinoma, detection of metastases is of utmost importance, because advanced tumors preclude curative surgical therapy. We present here our first experience of fluorescence-based diagnostic laparoscopy in a patient with hepatocellular carcinoma. We performed diagnostic laparoscopy in a 76-year-old woman who presented with a tumor of the liver and increased serum levels of alpha-fetoprotein. For photosensitization, 5-aminolevulinic acid (20 mg/kg bodyweig…
Modulation of central corneal thickness by various riboflavin eyedrop compositions in porcine corneas
2012
Purpose To evaluate the modulatory effect of various riboflavin 0.1% and 0.2% compositions on the central corneal thickness (CCT) in fresh porcine corneas. Setting Department of Ophthalmology, Johannes Gutenberg University of Mainz, Mainz, Germany. Design Experimental study. Methods The CCT in freshly enucleated porcine globes was measured by ultrasound pachymetry before and after (if applicable) deepithelialization and every 10 minutes thereafter during 120 minutes of eyedrop application. In Groups 1 and 2 (controls), no eyedrops were applied. In Groups 3 and 4, isotonic riboflavin eyedrops were used. In Groups 5 to 9, hypotonic riboflavin eyedrops were given. In Groups 10 and 11, preparat…
Long-Segment Early Squamous Cell Carcinoma of the Proximal Esophagus: Curative Treatment and Long-Term Follow-Up after 5-Aminolevulinic Acid (5-ALA)-…
2006
Photodynamic therapy (PDT) is an established treatment for the ablation of dysplastic Barrett's epithelium and early esophageal carcinoma, but no data have been published on curative 5-aminolevulinic acid (5-ALA)-PDT for long-segment early esophageal cancer with infiltration of the upper sphincter. We describe successful curative treatment of an unusual early long-segment squamous cell carcinoma (uT1a,N0) of the proximal esophagus (18 - 28 cm aborally), with three sessions of 5-ALA-PDT. Endoscopic and endosonographic follow-up macroscopically showed a complete remission of the tumor, proven by biopsy showing total histological ablation. After a follow-up period of 23 months, there has been …