We present a method to map fluorescence resonance energy transfer (FRET) parameters of a bifunctional photodynamic therapy agent, (2‐[1‐hexyloxyethyl]‐2‐devinyl pyropheophorbide‐a)‐cyanine dye (HPPH‐CD) conjugate, which consists of a photosensitizer (HPPH) and a fluorescent agent CD. We utilized time‐domain fluorescence diffuse optical tomography, the normalized Born ratio model in the Fourier‐domain, and an iterative algorithm to map depth‐resolved spatial heterogeneities of FRET parameters. Our results exhibited depth‐resolved changes of fluorophore's lifetime and the distance maps due to FRET between HPPH and CD. Our model suggests a potential approach of using FRET parameters to monitor efficacies of multifunctional photodynamic therapy agents in deep tissue.

中文翻译：

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使用时域荧光漫射光学层析成像法绘制双功能剂的荧光共振能量转移参数

我们提出了一种方法来绘制双功能光动力治疗剂（（2- [1- [己氧基乙基]]-2-癸基焦脱镁叶绿酸-a）-花青染料（HPPH-CD）共轭物的荧光共振能量转移（FRET）参数的图光敏剂（HPPH）和荧光剂CD。我们利用时域荧光漫射光学层析成像，傅立叶域中的归一化Born比模型和迭代算法来绘制FRET参数的深度解析空间异质性。我们的结果显示了荧光团寿命的深度分辨变化以及由于HPPH和CD之间的FRET而导致的距离图。我们的模型提出了一种潜在的方法，即使用FRET参数来监测多功能光动力疗法药物在深部组织中的功效。