Quantitative determination of doxorubicin in the exosomes of A549/MCF-7 cancer cells and human plasma using ultra performance liquid chromatography-tandem mass spectrometry.

In cancer therapy, exosomes efflux enhances resistance of cancer cells toward anticancer agents through mediating the transport of anticancer drugs outside the cells. In this study, a rapid, simple and highly sensitive ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for the determination of Doxorubicin (DOX) in exosomes of cancer cells and human plasma using Ketotifen as an internal standard (IS). Plasma samples spiked with DOX and two cancer cell lines (A549 & MCF-7) were incubated with different concentrations of DOX and IS.

Indicators of late normal tissue response after radiotherapy for head and neck cancer: fibroblasts, lymphocytes, genetics, DNA repair, and chromosome aberrations.

Purpose: To investigate the relationship between late tissue response after radiotherapy, cellular sensitivity and DNA repair capacity measured in dermal fibroblasts and chromosomal aberrations measured in lymphocytes. The study was in particular designed to compare cellular parameters of patients with maximum differences in late tissue reactions.

Materials And Methods: The study was performed with 16 pair-wise matched head and neck cancer patients 2-7 years after curative therapy exhibiting maximum differences (grade 1 vs.