title: Methylsulfonyl Zn phthalocyanine: A polyvalent and powerful hydrophobic photosensitizer with a wide spectrum of photodynamic applications.
abstract: BACKGROUND
  The biomedical photodynamic principle is based on the light-induced and photosensitizer-mediated killing of unwanted or harmful cells by overproduction of reactive oxygen species. Motivated by the success of photodynamic therapy (PDT) against several types of tumors, further applications of this approach are constantly identified which require the design and synthesis of novel photosensitizers with specifically tailored properties for a particular clinical application.
  
  
  METHODS
  Hydrophobic photosensitizers are currently gaining attention and hence a tetramethylsulfonyl Zn(II) phthalocyanine (2) was designed with respect to the desired photoproperties. The photodynamic potential of 2 was assessed by the determination of its photophysical and photochemical properties, and by a large range of biological tests including its phototoxicity against cancer cells and Gram(+) bacteria. Unsubstituted ZnPc was used as a reference compound for comparison purposes.
  
  
  RESULTS
  Phthalocyanine 2 has a better oxygen generation and is more photostable than ZnPc. 2 is a polyvalent and powerful hydrophobic photosensitizer with a wide spectrum of photodynamic applications against cancer (tested on A431 cells) and for Gram(+) PDI. Against Staphylococcus aureus, a maximum photokilling efficiency of more than 6 log10 steps was induced by a 5μM concentration of 2, outperforming the 3 log10 criterion for an antimicrobial effect (according to the recommendation of the American Society for Microbiology) by more than three orders of magnitude.
  
  
  CONCLUSIONS
  Phthalocyanine 2 has attractive photophysical and -chemical characteristics. Initial evaluation of its application in anti-tumor PDT and PDI suggest potential for further pre-clinical and clinical development of this compound.
authors.affiliation: Department of Chemistry, Gebze Technical University, P. O. Box 141, Gebze 41400, Kocaeli, Turkey.
authors.forename: Ümit
authors.initials: Ü
authors.lastname: İşci
authors.affiliation: Laboratory for Tumour Biology and Experimental Therapies, Institute of Physiology and Pathophysiology, Paracelsus Medical University, Strubergasse 21, 5020 Salzburg, Austria.
authors.forename: Marlena
authors.initials: M
authors.lastname: Beyreis
authors.affiliation: Laboratory of Photodynamic Inactivation of Microorganisms, Department of Materials Science and Physics, University of Salzburg, Hellbrunnerstrasse 34, 5020 Salzburg, Austria.
authors.forename: Nicole
authors.initials: N
authors.lastname: Tortik
authors.affiliation: Department of Chemistry, Gebze Technical University, P. O. Box 141, Gebze 41400, Kocaeli, Turkey.
authors.forename: Sevinc Z
authors.initials: SZ
authors.lastname: Topal
authors.affiliation: Laboratory of Photodynamic Inactivation of Microorganisms, Department of Materials Science and Physics, University of Salzburg, Hellbrunnerstrasse 34, 5020 Salzburg, Austria.
authors.forename: Michael
authors.initials: M
authors.lastname: Glueck
authors.affiliation: Department of Chemistry, Gebze Technical University, P. O. Box 141, Gebze 41400, Kocaeli, Turkey.
authors.forename: Vefa
authors.initials: V
authors.lastname: Ahsen
authors.affiliation: Department of Chemistry, Gebze Technical University, P. O. Box 141, Gebze 41400, Kocaeli, Turkey. Electronic address: fdumoulin@gtu.edu.tr.
authors.forename: Fabienne
authors.initials: F
authors.lastname: Dumoulin
authors.affiliation: Laboratory for Tumour Biology and Experimental Therapies, Institute of Physiology and Pathophysiology, Paracelsus Medical University, Strubergasse 21, 5020 Salzburg, Austria; Department of Internal Medicine I, Salzburger Landeskliniken / Paracelsus Medical University, Müllner Hauptstraße 48, 5020 Salzburg, Austria.
authors.forename: Tobias
authors.initials: T
authors.lastname: Kiesslich
authors.affiliation: Laboratory of Photodynamic Inactivation of Microorganisms, Department of Materials Science and Physics, University of Salzburg, Hellbrunnerstrasse 34, 5020 Salzburg, Austria.
authors.forename: Kristjan
authors.initials: K
authors.lastname: Plaetzer
mesh_terms: D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects* / Q000528:radiation effects; D004926:Escherichia coli / Q000187:drug effects* / Q000502:physiology* / Q000528:radiation effects; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D007211:Indoles / Q000008:administration & dosage* / Q000138:chemical synthesis; D054833:Isoindoles; D008422:Materials Testing; D009374:Neoplasms, Experimental / Q000188:drug therapy* / Q000473:pathology; D009942:Organometallic Compounds / Q000008:administration & dosage* / Q000138:chemical synthesis; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000737:chemistry / Q000627:therapeutic use; D016896:Treatment Outcome; D017967:Zinc Compounds
chemical_list: D007211:Indoles; D054833:Isoindoles; D009942:Organometallic Compounds; D017319:Photosensitizing Agents; D017967:Zinc Compounds; C052159:Zn(II)-phthalocyanine
keywords: In vitro; Photodynamic inactivation; Photodynamic therapy; Phthalocyanine; Singlet oxygen generation