2P-25 PDF
Development of Laser Ionization Techniques Using Zeolite Matrix for Simultaneous Imaging of Multiple Drugs Administered in Cancer Cells
To evaluate the efficacy of combined therapy using chemotherapy and photodynamic therapy, it is necessary to assess the uptakes of an anticancer drug and a photosensitizing drug in cancer cells. We employed MALDI-imaging mass spectrometry (IMS) to simultaneously observe the multiple drugs. Since the ionization efficiency of an anticancer drug, docetaxel, has been too low for conventional MALDI-IMS, zeolite matrix made by mixing a conventional organic matrix, 6-aza-2-thiothymine, and zeolite NaY5.6 was used, and we examined the simultaneous detection of docetaxel and a photosensitizing drug, protoporphyrin IX (PpIX), administered in cancer cells. In droplet method, PpIX and docetaxel was simultaneously detected. Therefore, it was confirmed that the zeolite matrix was effective for the ionization of these drugs administered in PC-3 cells. In spray method, PpIX was detected, while docetaxel was not. Since the peaks of ions originated in the phospholipids in the cell membrane were detected, it was supposed that the cell membrane might inhibit the co-crystallization of docetaxel and the zeolite matrix. In future works, methods to remove the cell membrane will be investigated. Additionally, we succeeded the IMS of PpIX administered in PC-3 cells cultured on the glass slide. For the simultaneous IMS, sample preparation should be optimized.