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: 6349416
• 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: 2000
• 资助国家: 美国
• 起止时间: 2000-09-01 至 2001-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6349416
• 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.

人们普遍认为光动力疗法以线粒体为目标 当使用卟啉和其他光敏剂时。 我们已经用过 细胞 NAD(P)H 的多光子代谢成像以监测 Photofrin（一种卟啉光敏剂）的作用。 光敏素和 NADH 可同时被 750 nm 多光子激发 辐照。 在单层细胞和多细胞肿瘤球体中， Photofrin 可使 NAD(P)H 减少大约两倍 自发荧光。 从自发荧光的观察 吸收，看来这种下降与 Photofrin 是同时发生的 进入质膜。 在 PDT 期间，观察到 NAD(P)H 对于相对较短的照射，以剂量依赖性方式减少。 没想到，这个趋势最终出现逆转，信号已经出现 观察到 PDT 期间的水平比 PDT 前水平增加了 5 倍 治疗。 我们目前正在评估这些的重要性 观察和测试可能解释的假设机制 这种行为。