Hart Michael C, Isuri Ritesh K, Ramos Drew, Osharovich Sofya A, Rodriguez Andrea E, Harmsen Stefan, Dudek Grace C, Huck Jennifer L, Holt David E, Popov Anatoliy V, Singhal Sunil, Delikatny Edward J
Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States.
Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104, United States.
Chem Biomed Imaging. 2024 Jun 20;2(7):490-500. doi: 10.1021/cbmi.4c00026. eCollection 2024 Jul 22.
Lung cancer, the most common cause of cancer-related death in the United States, requires advanced intraoperative detection methods to improve evaluation of surgical margins. In this study we employed DDAO-arachidonate (DDAO-A), a phospholipase A2 (PLA2) activatable fluorophore, designed for the specific optical identification of lung cancers in real-time during surgery. The fluorescence activation of DDAO-A by porcine sPLA2 was tested in various liposomal formulations, with 100 nm extruded EggPC showing the best overall characteristics. Extruded EggPC liposomes containing DDAO-A were tested for their stability under various storage conditions, demonstrating excellent stability for up to 4 weeks when stored at -20 °C or below. Cell studies using KLN 205 and LLC1 lung cancer cell lines showed DDAO-A activation was proportional to cell number. DDAO-A showed preferential activation by human recombinant cPLA2, an isoform highly specific to arachidonic acid-containing lipids, when compared to a control probe, DDAO palmitate (DDAO-P). studies with DBA/2 mice bearing KLN 205 lung tumors recapitulated these results, with preferential activation of DDAO-A relative to DDAO-P following intratumoral injection. Topical application of DDAO-A-containing liposomes to human (n = 10) and canine (n = 3) lung cancers demonstrated the preferential activation of DDAO-A in tumor tissue relative to adjacent normal lung tissue, with fluorescent tumor-to-normal ratios (TNR) of up to 5.2:1. The combined results highlight DDAO-A as a promising candidate for clinical applications, showcasing its potential utility in intraoperative and back-table imaging and topical administration during lung cancer surgeries. By addressing the challenge of residual microscopic disease at resection margins and offering stability in liposomal formulations, DDAO-A emerges as a potentially valuable tool for advancing precision lung cancer surgery and improving curative resection rates.
肺癌是美国癌症相关死亡的最常见原因，需要先进的术中检测方法来改善手术切缘的评估。在本研究中，我们使用了DDAO-花生四烯酸盐（DDAO-A），一种磷脂酶A2（PLA2）可激活的荧光团，设计用于在手术期间实时对肺癌进行特异性光学识别。在各种脂质体制剂中测试了猪分泌型PLA2对DDAO-A的荧光激活，100nm挤压的蛋黄卵磷脂（EggPC）表现出最佳的总体特性。测试了含有DDAO-A的挤压EggPC脂质体在各种储存条件下的稳定性，表明在-20°C或更低温度下储存时，其稳定性极佳，长达4周。使用KLN 205和LLC1肺癌细胞系进行的细胞研究表明，DDAO-A的激活与细胞数量成正比。与对照探针DDAO棕榈酸盐（DDAO-P）相比，DDAO-A显示出被人重组胞质型PLA2优先激活，人重组胞质型PLA2是一种对含花生四烯酸脂质高度特异性的同工型。对携带KLN 205肺肿瘤的DBA/2小鼠进行的研究重现了这些结果，瘤内注射后DDAO-A相对于DDAO-P优先激活。将含DDAO-A的脂质体局部应用于人类（n = 10）和犬类（n = 3）肺癌，结果表明相对于相邻正常肺组织，肿瘤组织中DDAO-A优先激活，荧光肿瘤与正常比值（TNR）高达5.2:1。综合结果突出了DDAO-A作为临床应用有前景的候选者，展示了其在肺癌手术中的术中及台后成像和局部给药方面的潜在效用。通过应对切除边缘残留微小疾病的挑战并在脂质体制剂中提供稳定性，DDAO-A成为推进精准肺癌手术和提高根治性切除率的潜在有价值工具。
