The fluorescence from protoporphyrin IX (PpIX) has been employed to characterise cellular activity and assist in the visualisation of tumour cells. Its formation can be induced by 5-aminolevulonic acid (5-ALA) which is metabolised by tumour cells to form PpIX. The PpIX is localised within the cells, rather than spreading into the vascular system. This, plus its photophysics, exhibits potential in photodynamic therapy. Hence its study and the ability to rapidly image its localisation is of importance, especially in the field of fluorescence guided surgery. This has led to investigations using tissue phantoms and widefield intensity imaging. Aggregation or the presence of photoproducts can alter PpIX emission, which has implications using widefield imaging and a broad wavelength range detection. The use of the fluorescence lifetime imaging (FLIM) is therefore advantageous as it can distinguish between the emissive species as they exhibit different fluorescence lifetimes. Here we use PpIX in a construct consisting of lipid mixture (Intralipid), employed to simulate fat content and optical scattering, in a gellan gum matrix. PpIX in intralipid in aqueous solution was injected into the gellan host to form inclusions. The samples are imaged using commercial widefield TCSPC camera based on a sensor chip with 192נ128 pixels. Each pixel contains both detection and photon timing enabling the Fluorescence Lifetime Acquisition by Simultaneous Histogramming (FLASH). This ‘FLASH-FLIM’ approach enables widefield fluorescence lifetime images, displayed in real time to be acquired, which has potential for use in visualising tumour boundaries.

来自原卟啉 IX (PpIX) 的荧光已被用于表征细胞活性并有助于肿瘤细胞的可视化。它的形成可由被肿瘤细胞代谢形成 PpIX 的 5-氨基乙酰丙酸 (5-ALA) 诱导。PpIX 位于细胞内，而不是扩散到血管系统中。这一点，加上它的光物理学，在光动力疗法中表现出潜力。因此，它的研究和快速成像其定位的能力非常重要，特别是在荧光引导手术领域。这导致了使用组织模型和宽场强度成像的研究。聚集或光产物的存在可以改变 PpIX 发射，这对使用宽场成像和宽波长范围检测具有影响。因此，使用荧光寿命成像 (FLIM) 是有利的，因为它可以区分发射物种，因为它们表现出不同的荧光寿命。在这里，我们在由脂质混合物（Intralipid）组成的结构中使用 PpIX，用于模拟结冷胶基质中的脂肪含量和光学散射。Intralipid 水溶液中的 PpIX 被注入结冷胶宿主以形成包涵体。使用基于 192 到 128 像素传感器芯片的商用宽场 TCSPC 相机对样品进行成像。每个像素都包含检测和光子定时，可通过同步直方图 (FLASH) 实现荧光寿命采集。这种“FLASH-FLIM”方法可以获取实时显示的宽场荧光寿命图像，具有用于可视化肿瘤边界的潜力。