title: Development of laser ionization techniques for evaluation of the effect of cancer drugs using imaging mass spectrometry.
abstract: Recently, combined therapy using chemotherapy and photodynamic therapy (PDT) has been proposed as a means of improving treatment outcomes. In order to evaluate the efficacy of combined therapy, it is necessary to determine the distribution of the anticancer drug and the photosensitizer. We investigated the use of imaging mass spectrometry (IMS) to simultaneously observe the distributions of an anticancer drug and photosensitizer administered to cancer cells. In particular, we sought to increase the sensitivity of detection of the anticancer drug docetaxel and the photosensitizer protoporphyrin IX (PpIX) by optimizing the ionization-assisting reagents. When we used a matrix consisting of equal weights of a zeolite (NaY5.6) and a conventional organic matrix (6-aza-2-thiothymine) in matrix-assisted laser desorption/ionization, the signal intensity of the sodium-adducted ion of docetaxel (administered at 100 μM) increased about 13-fold. Moreover, we detected docetaxel with the zeolite matrix using the droplet method, and detected PpIX by fluorescence and IMS with α-cyano-4-hydroxycinnamic acid (CHCA) using the spray method.
authors: Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan. kannen-h@mb.see.eng.osaka-u.ac.jp.
authors: Hiroki
authors: H
authors: Kannen
authors: Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan. hazama-h@see.eng.osaka-u.ac.jp.
authors: Hisanao
authors: H
authors: Hazama
authors: Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan. kaneday@gts.med.osaka-u.ac.jp.
authors: Yasufumi
authors: Y
authors: Kaneda
authors: Graduate School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minamiosawa Hachioji, Tokyo 192-0397, Japan. fujino@tmu.ac.jp.
authors: Tatsuya
authors: T
authors: Fujino
authors: Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan. awazu@see.eng.osaka-u.ac.jp.
authors: Kunio
authors: K
authors: Awazu
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry*; D045744:Cell Line, Tumor; D000077143:Docetaxel; D006801:Humans; D017319:Photosensitizing Agents / Q000737:chemistry*; D011524:Protoporphyrins / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D043823:Taxoids / Q000737:chemistry*; D017641:Zeolites / Q000737:chemistry
chemical_list: D000970:Antineoplastic Agents; D017319:Photosensitizing Agents; D011524:Protoporphyrins; D043823:Taxoids; D017641:Zeolites; D000077143:Docetaxel; C028025:protoporphyrin IX