ACTION SPECTRUM OF DNA SYNTHESIS INHIBITION AFTER FEMTOSECOND ILLUMINATION

飞秒光照后 DNA 合成抑制的作用谱

• 批准号: 6206150
• 负责人: JENNIFER A NICHOLS
• 金额: $ 1.72万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-09-01 至 2000-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6206150
• 关键词: animal tissue; bioengineering /biomedical engineering; biological products; biomedical resource; connective tissue; growth /development; lasers; technology /technique

Photodynamic therapy is commonly believed to target mitochondria when porphyrin and other photosensitizers are employed. We have used multiphoton metabolic imaging of cellular NAD(P)H as to monitor the effects of Photofrin, a porphyrin photosensitizer. Both Photofrin and NADH can simultaneously be multiphoton excited with 750 nm irradiation. In both monolayer cells and multicell tumor spheroids, Photofrin is seen to cause approximately two-fold reduction of NAD(P)H autofluorescence. From observations of autofluorescence during uptake, it appears that this decrease is concurrent with Photofrin entering the plasma membrane. During PDT, NAD(P)H is observed to decrease in a dose dependent manner for relatively short irradiations. Unexpectedly, this trend eventually reverses and the signal has been observed to increase as much as 5 fold from pre-PDT levels during therapy. We are currently assessing the significance of these observations and testing hypothetical mechanisms that might explain this behavior.

光动力疗法通常被认为是以线粒体为靶点。 当使用卟啉和其他光敏剂时。我们已经使用了 细胞NAD(P)H的多光子代谢成像监测 光敏剂光敏剂Photofrin的作用。Photofrin和 NADH可以同时被750 nm多光子激发 辐射。在单层细胞和多细胞肿瘤球体中， 光敏剂可使NAD(P)H减少约两倍 自体荧光。从观察到的自体荧光在 摄取，这一下降似乎与照相同时发生 进入质膜。在PDT过程中，观察到NAD(P)H 对于相对较短的照射，以剂量依赖的方式减少。 出乎意料的是，这一趋势最终逆转，信号一直是 观察到比PDT前增加了5倍 心理治疗。我们目前正在评估这些措施的重要性 观察和测试假设机制，可能解释 这种行为。