Synthesis and characterization of photodynamic activity of an iodinated Chlorin p 6 copper complex

• Published in: RSC advances 2016, Vol.6 (79), p.75782-75792
• Main Authors: Sarbadhikary, Paromita, Dube, Alok, Gupta, Pradeep Kumar
• Format: Article
• Language: English
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/C6RA14026B

We report the synthesis of a new iodinated Chlorin p 6 copper complex (IC p 6 –Cu) and its efficacy for photodynamic treatment (PDT) of cancer cells. The metal complex is obtained by reacting Chlorin p 6 (C p 6 ) with copper iodide (CuI). The complex formation results in a shift in the Q absorption band of C p 6 from 663 nm to 634 nm and X-ray fluorescence of the complex showed the presence of both copper and iodine. FTIR and EPR spectroscopy suggests that the copper is attached to C p 6 at the two adjacent carboxylic groups. Studies on the photochemical generation of singlet oxygen ( 1 O 2 ) and other reactive oxygen species (ROS) using fluorescence probes revealed that IC p 6 –Cu acts predominantly through the type I process. PDT of oral cancer cells with IC p 6 –Cu (10 μM, 3 h) and red light (630 ± 20 nm, ∼12 J cm −2 ) led to ∼90% phototoxicity. Furthermore, in contrast to C p 6 , the phototoxicity induced by IC p 6 –Cu is not significantly affected under hypoxic conditions.