Bhawalkar J D, Kumar N D, Zhao C F, Prasad P N
Department of Chemistry State University of New York at Buffalo, NY 14260-3000, USA.
J Clin Laser Med Surg. 1997;15(5):201-4. doi: 10.1089/clm.1997.15.201.
We demonstrate the use of infrared excitation in conjunction with an efficient two-photon absorbing dye and a photosensitizer in photodynamic therapy.
An efficient two-photon absorbing dye is excited by short infrared (800 nm) laser pulses, which transfer its energy to the photosensitizer and the photosensitizer, in turn, generates the singlet oxygen.
A new approach to photodynamic cancer therapy based on the strong two-photon absorption of certain newly developed organic molecules. Near infrared pulsed laser light efficiently excites these molecules which, in turn, transfer the energy to the photosensitizer used in photodynamic therapy.
A newly synthesized two-photon absorbing dye 4-[N-(2-hydroxyethyl)-N-(methyl) amino phenyl]-4'-(6-hydroxyhexyl sulfonyl)stilbene (APSS), which exhibits a strong two-photon absorption at 800 nm, and upconverted fluorescence at 520 nm, in solution in the presence of a photosensitizer was found to generate singlet oxygen under infrared excitation (800 nm). The generation of singlet oxygen in a reaction system containing two-photon absorbing dye and photosensitizer under infrared excitation has been chemically detected by using ADPA (9,10-anthracenedipropionic acid) as singlet oxygen detector.
The efficient two-photon absorption of certain chromophores can be used to extend photodynamic therapy to the near infrared spectral region. Whereas the photosensitizer itself may not exhibit two-photon absorption, it could be used in conjunction with one of these new chromophores. The chromophores can act as "photon harvesters" whereby they absorb two photons of near infrared light and transfer the energy to the photosensitizer, which can generate singlet oxygen in the presence of atmospheric oxygen.
我们展示了在光动力疗法中结合使用红外激发、高效双光子吸收染料和光敏剂的情况。
一种高效双光子吸收染料由短红外（800纳米）激光脉冲激发，该激光脉冲将其能量传递给光敏剂，而光敏剂进而产生单线态氧。
基于某些新开发有机分子的强双光子吸收，提出一种光动力癌症治疗的新方法。近红外脉冲激光有效地激发这些分子，这些分子进而将能量传递给光动力疗法中使用的光敏剂。
一种新合成的双光子吸收染料4-[N-(2-羟乙基)-N-(甲基)氨基苯基]-4'-(6-羟基己基磺酰基)芪（APSS），在800纳米处表现出强双光子吸收，在520纳米处有上转换荧光，发现在光敏剂存在的溶液中，在红外激发（800纳米）下能产生单线态氧。通过使用ADPA（9,10-蒽二丙酸）作为单线态氧探测器，已对在红外激发下含有双光子吸收染料和光敏剂的反应体系中单线态氧的产生进行了化学检测。
某些发色团的高效双光子吸收可用于将光动力疗法扩展到近红外光谱区域。虽然光敏剂本身可能不表现出双光子吸收，但它可与这些新发色团之一结合使用。发色团可充当“光子收集器”，借此它们吸收两个近红外光光子并将能量传递给光敏剂，光敏剂在大气氧存在下可产生单线态氧。
