Control of Photobleaching in Photodynamic Therapy Using the Photodecarbonylation Reaction of Ruthenium Phthalocyanine Complexes via Stepwise Two-Photon Excitation
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- 作者：Kazuyuki Ishii ; Masahiko Shiine ; Yoshitaka Shimizu ; Shun-ichi Hoshino ; Hisaku Abe ; Kazuhiro Sogawa ; Nagao Kobayashi
- 刊名：Journal of Physical Chemistry B
- 出版年：2008
- 出版时间：March 13, 2008
- 年：2008
- 卷：112
- 期：10
- 页码：3138 - 3143
- 全文大小：133K
- 年卷期：v.112,no.10(March 13, 2008)
- ISSN：1520-5207
文摘
In this study, we have investigated the photochemical properties and photodynamic effects of rutheniumphthalocyanine (RuPc(CO)(Py)) and naphthalocyanine (RuNc(CO)(Py)) complexes. When a nanosecond-pulsed laser is used, the photodecarbonylation of our Ru complexes efficiently proceeds via stepwise two-photon excitation, while the reaction yields are negligibly small when a continuous-wave (CW) laser isemployed. The pulsed laser selective photodecarbonylation decreases the Q-band absorbance, which satisfieswhat the photodynamic therapy (PDT) requires of the photobleaching. For RuPc(CO)(Py), the photochemicalreactions including both the photodecarbonylation and just photobleaching occur in HeLa cells in vitro. Toxicityand phototoxicity tests indicate that our RuPc(CO)(Py) and RuNc(CO)(Py) complexes in concentrations of0.3-1 
M and 1-2 M, respectively, are applicable as PDT agents. The phototoxicity is consistent with thephotochemical properties of these complexes, namely, excited triplet lifetimes (10 and 4.8 s for the Pc andNc complexes, respectively) and singlet oxygen yields (0.48 and 0.35 for the Pc and Nc complexes,respectively). On the basis of these results, we propose a novel concept for achieving a greater depth ofnecrosis in PDT as follows: (1) PDT of upper cellular layers using CW-laser irradiation; (2) efficientphotobleaching in upper cellular layers using pulsed dye-laser irradiation, which results in an increase in thetherapeutic depth of red light; (3) PDT directed toward deeper tumor tissues using CW laser irradiation. Inaddition, these Ru complexes are promising as CO release agents for investigative biochemistry.
M and 1-2 M, respectively, are applicable as PDT agents. The phototoxicity is consistent with thephotochemical properties of these complexes, namely, excited triplet lifetimes (10 and 4.8 s for the Pc andNc complexes, respectively) and singlet oxygen yields (0.48 and 0.35 for the Pc and Nc complexes,respectively). On the basis of these results, we propose a novel concept for achieving a greater depth ofnecrosis in PDT as follows: (1) PDT of upper cellular layers using CW-laser irradiation; (2) efficientphotobleaching in upper cellular layers using pulsed dye-laser irradiation, which results in an increase in thetherapeutic depth of red light; (3) PDT directed toward deeper tumor tissues using CW laser irradiation. Inaddition, these Ru complexes are promising as CO release agents for investigative biochemistry.