title: Matrix-assisted laser desorption/ionization, nanostructure-assisted laser desorption/ionization and carbon nanohorns in the detection of antineoplastic drugs. 1. The cases of irinotecan, sunitinib and 6-alpha-hydroxy paclitaxel.
abstract: The development of surface-assisted laser desorption/ionization (SALDI) methodologies in mass spectrometry allows, in principle, the development of new analytical approaches to qualitative and quantitative measurements on small molecules. Some of these methods have been applied to characterize two antineoplastic drugs: irinotecan (1) and sunitinib (2), and also 6-α-hydroxy-paclitaxel (3), the main metabolite of paclitaxel. Three different SALDI approaches have been tested employing nanostructure- assisted laser desorption/ionization (NALDI), carbon nanohorns (NHs) and carbon nanohorns covered by liquid additives. The results so obtained have been compared to those observed under matrix-assisted laser desorption/ionization (MALDI) conditions. Compounds 1 and 2 show the easy formation of protonated molecular species under all the experimental conditions, but the highest absolute intensity was achieved by NALDI. On the contrary, ionic species of low intensity are present for 3, among which are those that exhibit the highest intensity caused by [M+K](+) ions. After a critical evaluation of the obtained data, the linear response of the [M+H](+) ion intensity of 1 versus different deposited sample amounts was investigated, and the best results (R(2) = 0.9889) were obtained under MALDI conditions. The analysis of plasma samples spiked with 1 showed, again, that the MALDI approach was the best one (R(2) = 0.9766). The failure of NALDI measurements could be rationalized by the presence of ion suppression effects.
authors.affiliation: IENI CNR, Corso Stati Uniti 4, 35127 Padova (PD), Italy. Istituto di Ricerca Pediatrica - Città della Speranza, Corso Stati Uniti 4, 35127 Padova, Italy. pietro.traldi@adr.pd.cnr.it.
authors.forename: Pietro
authors.initials: P
authors.lastname: Traldi
authors.affiliation: Istituto di Ricerca Pediatrica - Città della Speranza, Corso Stati Uniti 4, 35127 Padova, Italy. Experimental and Clinical Pharmacology Unit, Centro di Riferimento Oncologico, IRCCS National Cancer Institute, Via Franco Gallini 2, 33081 Aviano (PN), Italy. e.calandra@irpcds.org.
authors.forename: Eleonora
authors.initials: E
authors.lastname: Calandra
authors.affiliation: Istituto di Ricerca Pediatrica - Città della Speranza, Corso Stati Uniti 4, 35127 Padova, Italy. Experimental and Clinical Pharmacology Unit, Centro di Riferimento Oncologico, IRCCS National Cancer Institute, Via Franco Gallini 2, 33081 Aviano (PN), Italy. s.crotti@yahoo.it.
authors.forename: Sara
authors.initials: S
authors.lastname: Crotti
authors.affiliation: Istituto di Ricerca Pediatrica - Città della Speranza, Corso Stati Uniti 4, 35127 Padova, Italy. Surgical Clinic, Department of Surgical, Oncological and Gastroenterological Sciences, University of Padova, Via Nicolo Giustiniani 2, 35128 Padova, Italy. Department of Nanomedicine, The Methodist Hospital Research Institute, 6670 Bertner Avenue, Houston, 77030 TX, USA. m.agostini@unipd.it.
authors.forename: Marco
authors.initials: M
authors.lastname: Agostini
authors.affiliation: Surgical Clinic, Department of Surgical, Oncological and Gastroenterological Sciences, University of Padova, Via Nicolo Giustiniani 2, 35128 Padova, Italy. donato.nitti@unipd.it.
authors.forename: Donato
authors.initials: D
authors.lastname: Nitti
authors.affiliation: Dipartimento di Medicina, Università degli Studi di Padova, Via Giustiniani 2, I-35100 Padova, Italy. marco.reverso@gmail.com.
authors.forename: Marco
authors.initials: M
authors.lastname: Roverso
authors.affiliation: Experimental and Clinical Pharmacology Unit, Centro di Riferimento Oncologico, IRCCS National Cancer Institute, Via Franco Gallini 2, 33081 Aviano (PN), Italy. gtoffoli@cro.it.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Toffoli
authors.affiliation: Experimental and Clinical Pharmacology Unit, Centro di Riferimento Oncologico, IRCCS National Cancer Institute, Via Franco Gallini 2, 33081 Aviano (PN), Italy. emarangon@cro.it.
authors.forename: Elena
authors.initials: E
authors.lastname: Marangon
authors.affiliation: Experimental and Clinical Pharmacology Unit, Centro di Riferimento Oncologico, IRCCS National Cancer Institute, Via Franco Gallini 2, 33081 Aviano (PN), Italy. bianca.posocco@live.it.
authors.forename: Bianca
authors.initials: B
authors.lastname: Posocco