荧光成像仪器的成像性能测试对于提高仪器的性能和临床转化成功率具有重要意义，成像性能测试的标准化需要一种可以精确模拟荧光光谱的长期稳定的样品作为测试工具。本团队提出了一种荧光发光模拟系统，该系统可以模拟荧光样品的激发效率、荧光发射谱特性和荧光空间分布特性，可以替代真实的荧光剂仿体对荧光成像类仪器进行量化表征。该系统采用的是基于线性滤光片和液晶显示器的光谱模拟方法。本团队还设计了一种改进的最小二乘光谱拟合算法，该算法可以自动模拟任意荧光发射谱。使用该系统模拟了近红外荧光造影剂吲哚菁绿(ICG)的发光特性，并对不同荧光成像仪器的成像灵敏度进行了测试。实验结果表明，所设计的荧光发光模拟系统可以稳定精准地模拟荧光样品的发光特性。

Near infrared (NIR) fluorescence imaging guided photodynamic therapy (PDT) is a technique which has been developed in many clinical trials due to its advantage of real-time optical monitoring, specific spatiotemporal selectivity, and minimal invasiveness. For this, photosensitizers with NIR fluorescence emission and high 1O2 generation quantum yield are highly desirable. Herein, we designed and synthesized a "donor–acceptor" (D-A) structured semiconductor polymer (SP), which was then wrapped with an amphiphilic compound (Pluronicr F127) to prepare water-soluble nanoparticles (F-SP NPs). The obtained F-SP NPs exhibit good water solubility, excellent particle size stability, strong absorbance at deep red region, and strong NIR fluorescent emission characteristics. The maximal mass extinction coe±cient and fluorescence quantum yield of these F-SPs were calculated to be 21.7 L/(g·cm) and 6.5%, respectively. Moreover, the 1O2 quantum yield of 89% for F-SP NPs has been achieved under 635 nm laser irradiation, which is higher than Methylene Blue, Ce6, and PpIX. The outstanding properties of these F-SP NPs originate from their unique D-A molecular characteristic. This work should help guide the design of novel semiconductor polymer for NIR fluorescent imaging guided PDT applications.

为实现高信噪比(SNR)的深层生物组织成像，结合了激光扫描共聚焦成像技术和近红外(NIR)荧光成像技术，根据近红外荧光成像要求设计了一套激光扫描共聚焦近红外荧光成像实验系统，对注入近红外荧光染料LDS925 小鼠的尾部成像后获得了小鼠尾部近红外荧光图像和近红外共聚焦荧光图像。实验结果表明小鼠尾部近红外共聚焦荧光图像信噪比显著优于小鼠尾部近红外荧光图像，采用均方差和峰谷(PV)值进行评估时，近红外荧光成像荧光信号强度分布的均方差值和PV 值分别为864 和102；共聚焦荧光成像的荧光信号强度分布的均方差值和PV 值分别为1459 和255；进一步表明激光扫描共聚焦成像技术在近红外荧光成像中应用是可行的，可以实现深层组织的高信噪比共聚焦成像。

合成了两种近红外有机荧光探针, 即叶酸-PEG-ICG-Der-01和LDL-ICG-Der-02, 它们分别以肿瘤表面高度表达的叶酸受体以及低密度脂蛋白(LDL)受体为靶点。探针复合物中的叶酸和低密度脂蛋白部分为探针分子提供靶向“导向”, 通过化学共价键分别与有机近红外染料ICG-Der-01和ICG-Der-02偶联, 近红外染料则为探针分子的荧光信号输出端。利用紫外分光光度计、近红外荧光光谱仪及近红外荧光成像系统分析这两种荧光探针的光学性质, 以及它们在叶酸受体及LDL受体过度表达的肿瘤鼠体内的成像过程。结果显示, 所合成的叶酸-PEG-ICG-Der-01和LDL-ICG-Der-02探针的荧光强度及光稳定性都高于对应的染料单体。而体内成像结果则表明两种探针都保持了叶酸和LDL的生物活性, 能有效地靶向到相关肿瘤部位, 成像清晰, 并且能最终代谢排出体外。比较这两种探针, 叶酸-PEG-ICG-Der-01对肿瘤细胞的靶向性要优于LDL-ICG-Der-02, 并能用于肿瘤早期诊断。