title: The fast method of Cu-porphyrin complex synthesis for potential use in positron emission tomography imaging.
abstract: Porphyrin based photosensitizers are useful agents for photodynamic therapy and fluorescence imaging of cancer. Additionally, porphyrins are excellent metal chelators, forming stable metalo-complexes and (64)Cu isotope can serve as a positron emitter (t1/2=12.7h). The other advantage of (64)Cu is its decay characteristics that facilitates the use of (64)Cu-porphyrin complex as a therapeutic agent. Thus, (64)Cu chelation with porphyrin photosensitizer may become a simple and versatile labeling strategy for clinical positron emission tomography. The present study reports a convenient method for the synthesis of Cu complex with tetrakis(4-carboxyphenyl)porphyrin (TCPP). The experimental conditions for labeling, such as the metal-to-ligand molar ratio, pH and time of reaction were optimized to achieve a high complexation efficiency in a short period of time as possible. In order to accelerate the metallation, the use of substitution reactions of cadmium or lead porphyrin and the presence of reducing agent, such as ascorbic acid, hydroxylamine and flavonoid - morin, were evaluated. The optimum conditions for the synthesis of the copper complex were borate buffer at pH9 with the addition of 10-fold molar excess, with respect to Cu(2+) ions and TCPP and ascorbic acid which resulted in reduction of the reaction time from 30 min to below 1 min.
authors.affiliation: Heavy Ion Laboratory, University of Warsaw, 5ath Pasteur Str., 02-093 Warsaw, Poland. Electronic address: kilian@slcj.uw.edu.pl.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Kilian
authors.affiliation: Faculty of Chemistry, University of Warsaw, 1st Pasteur Str., 02-093 Warsaw, Poland.
authors.forename: Maria
authors.initials: M
authors.lastname: Pęgier
authors.affiliation: Faculty of Chemistry, University of Warsaw, 1st Pasteur Str., 02-093 Warsaw, Poland.
authors.forename: Krystyna
authors.initials: K
authors.lastname: Pyrzyńska
mesh_terms: D002614:Chelating Agents / Q000138:chemical synthesis / Q000737:chemistry; D056831:Coordination Complexes / Q000138:chemical synthesis* / Q000737:chemistry; D003301:Copper Radioisotopes / Q000737:chemistry*; D008665:Metalloporphyrins / Q000138:chemical synthesis* / Q000737:chemistry; D010084:Oxidation-Reduction; D017319:Photosensitizing Agents / Q000138:chemical synthesis* / Q000737:chemistry; D011166:Porphyrins / Q000138:chemical synthesis / Q000737:chemistry; D049268:Positron-Emission Tomography
chemical_list: D002614:Chelating Agents; D056831:Coordination Complexes; D003301:Copper Radioisotopes; D008665:Metalloporphyrins; D017319:Photosensitizing Agents; D011166:Porphyrins; C018395:tetracarboxyphenylporphine
keywords: Copper-64; Porphyrin; Positron emission tomography