针对实现癌症精准光动力学治疗（PDT）的关键科学问题 , 本项目将位于生物光学窗口内的近红外光上转换纳米材料的上转换荧光成像（UCIM）与光敏剂的荧光寿命显微成像(FLIM)技术相结合, 以期研究构筑可监控的、精准靶向的、精准治疗的光动力治疗平台。重点研究：通过构筑高效近红外光激发的、具有表面靶向配体的纳米上转换光动力治疗材料，利用不激发生物体自体自荧光、发光稳定的上转换荧光纳米探针及FLIM技术监测纳米粒子的靶向过程及治疗过程, 对纳米粒子表面配体的靶向能力进行相关评估；利用UCIM和FLIM复合成像技术，动态监测低光损伤、穿透深度深的上转换纳米药物对癌细胞的杀伤过程及相关细胞微环境参数，实现对相关治疗参数的精准评估。开展上述重要问题的研究，将为癌症的精准的诊疗研究提供新的方法和手段，并提供了研究基础和科学依据，具有重要的科学意义和应用前景。

To face the difficulty that how to achieve precise photodynamic therapy (PDT) of cancer cells, the project will be located on constructing upconversion nanomaterials which convert the near-infrared light within optical biological window for upconversion imaging (UCIM), and associating with the fluorescence lifetime imaging microscopy (FLIM) technology of photosensitizer, to build a dynamicly monitored, precisely targeted and precisely treating photodynamic therapy platform. On one hand, the key research is to build efficient near-infrared light excited, targeted upconversion nano-photodynamic therapy platform, which utilize the stable UCIM with low autofluorescence, and FLIM to technically monitoring the targeted process of cancer cells. Then the targeting ability of nanoparticle for cancer cells will be precisely assessments and modified for more efficiently targeting. On the other hand, combing the UCIM and exquisite FLIM technology, dynamicly monitor the process of nano-drugs killing cancer cells. The results about the relating parameters about PDT and related cellular microenvironment information will help to achieve precisely assessment of the relevant treatment method, to establish more precise and efficient photodynamic therapy. This project examines the implementation of these important issues, accurate diagnosis and treatment for cancer research, which provides a foundation for presice therapy of cancers with important scientific significance and application prospects.