|YAMAKOSHI, Y. - University Of Pennsylvania
|AROUA, S. - University Of Pennsylvania
|IWAMOTO, Y. - University Of Pennsylvania
|OHNISHI, T. - University Of Pennsylvania
Submitted to: The Royal Society of Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/16/2014
Publication Date: 5/16/2014
Citation: Yamakoshi, Y., Aroua, S., Nguyen, T.D., Iwamoto, Y., Ohnishi, T. 2014. Water-soluble fullerene materials for bioapplications: photoinduced reactive oxygen species generation. Royal Society of Chemistry Meetings. 173(15):1-10. 10.1039/c4fd00076e.
Interpretive Summary: Fullerenes are used in photodynamic therapy as a photosensitizer which, when combined with oxygen and visible light, can induce nonthermal photochemical reaction in the treatment of solid tumors and many nonmalignant diseases. Recent researches on fullerenes attempted to improve their solubility by preparing their derivatives to be absorbed rapidly by tissues and then excreted through urinary tract and enterons. To better understand the effectiveness of fullerenes’ derivatives, four different kinds of water-soluble fullerene C60 were prepared and an investigation of their ability to generate photoinduced reactive oxygen species was conducted. The results are significantly clear: a) All four derivatives showed the generation of photoinduced reactive oxygen species via an energy transfer or an electron transfer mechanism. b) The tendency towards the generation of oxygen species was markedly different, though all of the reactions were performed in aqueous media. The results of this experiment, in combination with in vitro photo DNA cleaving testing and various oxygen scavengers studies, help evaluate the mechanism of reactive oxygen species generating from C60.
Technical Abstract: The photoinduced reactive oxygen species (ROS) generation from several water-soluble fullerenes was examined. Macromolecular or small molecular water-soluble fullerene complexes/derivatives were prepared and their 1O2 and O2•- generation abilities were evaluated by EPR spin-trapping methods. As a result, efficient 1O2 generation was detected from photoexcited C60, not only in organic solvents, but also in aqueous media and especially from small molecule C60–carboxylic acid derivatives. Whereas efficient O2•- generation was observed in the aqueous solution of the C60/'-CD complex under photoirradiation.