Antitumor Efficacy of Photodynamic Therapy Using Novel Nanoformulations of Hypocrellin Photosensitizer SL052

• Published in: Photochemistry and photobiology 2012-01, Vol.88 (1), p.188-193
• Main Authors: Korbelik, Mladen, Madiyalakan, Ragupathy, Woo, Thomas, Haddadi, Azita
• Format: Article
• Language: English
• Subjects: Cancer therapies; Morphology; Nanotechnology; Perylene - administration & dosage; Perylene - analogs & derivatives; Perylene - pharmacology; Photochemotherapy; Photodynamic therapy; Photosensitizing Agents - administration & dosage; Photosensitizing Agents - pharmacology; Polymers; Quinoxalines - administration & dosage; Quinoxalines - pharmacology
• ISSN: 0031-8655; 1751-1097
• DOI: 10.1111/j.1751-1097.2011.01035.x

Recent preclinical and clinical testing of hypocrellin‐based photosensitizer SL052 for use in photodynamic therapy (PDT) of cancer has shown encouraging results. Further optimization of its formulation for delivery could considerably extend the therapeutic efficiency of this drug. A nanoformulation encapsulating SL052 into biodegradable polymer poly(lactic‐co‐glycolic acid) (PLGA) was developed using a single‐emulsion solvent evaporation technique and characterized in terms of particle size and loading of the photosensitizing agent. This nanoformulation, SL052‐PLGA‐nanoparticles (NPs), was compared with recently created nanoformulation based on polyvinylpyrrolidone (SL052‐PVP‐NPs) and standard liposomal SL052 preparation in terms of efficacy when used for PDT treatment of squamous cell carcinomas SCCVII growing subcutaneously in syngeneic mice. The therapeutic effect of PDT using these three different SL052 formulations was tested for both 1 and 4 h intervals between drug injection and tumor light exposure. The longer time interval produced higher tumor cure rates with all SL052 preparations. With both drug‐light intervals, PDT based on SL052‐PLGA‐NPs produced superior therapeutic benefit compared with the other two SL052 formulations. Photodynamic therapy (PDT) agent, SL052, was formulated into two nanoformulations using either a biodegradable polymer poly(lactic‐co‐glycolic acid) (PLGA) or a polyvinylpyrrolidone (PVP) polymer. The formulations were applied for PDT treatment of squamous cell carcinomas SCCVII growing subcutaneously in syngeneic mice by intravenous injections. The PDT efficacy of the two nanoformulations and the standard liposomal SL052 preparation were evaluated and compared at two drug‐light intervals. The results demonstrated that PDT based on SL052 in PLGA formulation produced superior therapeutic benefit compared with the other two SL052 formulations.