TY - JOUR
T1 - Enhanced singlet oxygen generation from a porphyrin-rhodamine B dyad by two-photon excitation through resonance energy transfer
AU - Ngen, Ethel J.
AU - Xiao, Lixin
AU - Rajaputra, Pallavi
AU - Yan, Xingzhong
AU - You, Youngjae
N1 - Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 2013/7
Y1 - 2013/7
N2 - Mitochondrial-targeting photosensitizers have been associated with effective photodynamic responses. However, most photosensitizers absorb light between 400 and 700 nm, where light penetration through tissues is limited. Two-photon excitation is a rational approach to improve light penetration through tissues. In this report, the two-photon photophysical properties of a porphyrin-rhodamine B conjugate (TPP-Rh), previously demonstrated to target the mitochondria, were evaluated. The properties studied included: two-photon absorption (TPA) cross sections (σ2); resonance energy transfer (RET) kinetics and dynamics; and singlet oxygen generation. The conjugation of Rh B to TPP-OH approximately doubled the σ2 of TPP-Rh at 800 nm (40 ± 4 GM) compared with the parent porphyrin, TPP-OH (16 ± 4 GM). Furthermore, the rate of DPBF oxidation by singlet oxygen generated from TPP-Rh was twice as fast compared with that from TPP-OH (73 % versus 33% in 10 min) following two-photon excitation at 800 nm. In addition, a significantly stronger luminescence signal was detected from TPP-Rh, than from TPP-OH at 1270 nm, following two-photon excitation. This study indicates that conjugating photosensitizers to Rh B could provide greater TPA at the near-infrared range in addition to preferential mitochondrial accumulation for improved photodynamic responses.
AB - Mitochondrial-targeting photosensitizers have been associated with effective photodynamic responses. However, most photosensitizers absorb light between 400 and 700 nm, where light penetration through tissues is limited. Two-photon excitation is a rational approach to improve light penetration through tissues. In this report, the two-photon photophysical properties of a porphyrin-rhodamine B conjugate (TPP-Rh), previously demonstrated to target the mitochondria, were evaluated. The properties studied included: two-photon absorption (TPA) cross sections (σ2); resonance energy transfer (RET) kinetics and dynamics; and singlet oxygen generation. The conjugation of Rh B to TPP-OH approximately doubled the σ2 of TPP-Rh at 800 nm (40 ± 4 GM) compared with the parent porphyrin, TPP-OH (16 ± 4 GM). Furthermore, the rate of DPBF oxidation by singlet oxygen generated from TPP-Rh was twice as fast compared with that from TPP-OH (73 % versus 33% in 10 min) following two-photon excitation at 800 nm. In addition, a significantly stronger luminescence signal was detected from TPP-Rh, than from TPP-OH at 1270 nm, following two-photon excitation. This study indicates that conjugating photosensitizers to Rh B could provide greater TPA at the near-infrared range in addition to preferential mitochondrial accumulation for improved photodynamic responses.
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U2 - 10.1111/php.12071
DO - 10.1111/php.12071
M3 - Article
C2 - 23489066
AN - SCOPUS:84879845893
SN - 0031-8655
VL - 89
SP - 841
EP - 848
JO - Photochemistry and Photobiology
JF - Photochemistry and Photobiology
IS - 4
ER -