Significance: The study has confirmed the feasibility of using ultraviolet (UV) excitation to visualize and quantify desmoplasia in fresh tumor tissue of pancreatic adenocarcinoma (PDAC) in an orthotopic xenograft mouse model, which provides a useful imaging platform to evaluate acute therapeutic responses. Aim: Stromal network of collagen prominent in PDAC tumors is examined by imaging fresh tissue samples stained with histological dyes. Fluorescence signals are color-transferred to mimic Masson’s trichrome staining. Approach: Murine tumor samples were stained with Hoechst, eosin, and rhodamine B and excited at 275-nm. Fluorescence signals in the visible spectrum were captured by a CMOS color camera with high contrast and resolution at whole-tumor slice field of view. Results: Fluorescence imaging using UV excitation is capable of visualizing collagen deposition in PDAC tumors. Both fluorescence and histology data showed collagen content of up to 30%. The collagen modulation effect due to photodynamic priming treatment was observed showing 13% of collagen reduction. Necrosis area is visible and perfusion imaging using Texas Red dextran is feasible. Conclusions: The study demonstrates collagen visualization in fresh PDAC tumor samples using UV excitation. This imaging platform also provides quantitative stromal information from fiber analysis and visibility of necrosis and perfusion, suitable for therapeutic response assessment of photodynamic therapy.

中文翻译：

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通过紫外线表面激发对新鲜组织中胰腺肿瘤基质的可视化和量化

意义：该研究证实了在原位异种移植小鼠模型中使用紫外线 (UV) 激发可视化和量化胰腺腺癌 (PDAC) 新鲜肿瘤组织中结缔组织增生的可行性，为评估急性治疗反应提供了一个有用的成像平台。目的：通过对用组织学染料染色的新鲜组织样本进行成像来检查 PDAC 肿瘤中突出的胶原基质网络。荧光信号经过颜色转移以模拟马森三色染色。方法：小鼠肿瘤样本用 Hoechst、曙红和罗丹明 B 染色，并在 275 nm 处激发。可见光谱中的荧光信号由具有高对比度和分辨率的 CMOS 彩色相机在整个肿瘤切片视野中捕获。结果：使用紫外线激发的荧光成像能够可视化 PDAC 肿瘤中的胶原沉积。荧光和组织学数据均显示胶原蛋白含量高达 30%。观察到由于光动力引发处理引起的胶原蛋白调节效果显示胶原蛋白减少了 13%。坏死区域是可见的，使用德州红葡聚糖进行灌注成像是可行的。结论：该研究展示了使用紫外线激发的新鲜 PDAC 肿瘤样品中的胶原蛋白可视化。该成像平台还提供来自纤维分析和坏死和灌注可见性的定量基质信​​息，适用于光动力疗法的治疗反应评估。观察到由于光动力引发处理引起的胶原蛋白调节效果显示胶原蛋白减少了 13%。坏死区域是可见的，使用德州红葡聚糖进行灌注成像是可行的。结论：该研究展示了使用紫外线激发的新鲜 PDAC 肿瘤样品中的胶原蛋白可视化。该成像平台还提供来自纤维分析和坏死和灌注可见性的定量基质信​​息，适用于光动力疗法的治疗反应评估。观察到由于光动力引发处理引起的胶原蛋白调节效果显示胶原蛋白减少了 13%。坏死区域是可见的，使用德州红葡聚糖进行灌注成像是可行的。结论：该研究展示了使用紫外线激发的新鲜 PDAC 肿瘤样品中的胶原蛋白可视化。该成像平台还提供来自纤维分析和坏死和灌注可见性的定量基质信​​息，适用于光动力疗法的治疗反应评估。