title: Analysis of Chemotherapeutic Drug Delivery at the Single Cell Level Using 3D-MSI-TOF-SIMS.
abstract: In this work, we show the advantages of label-free, tridimensional mass spectrometry imaging using dual beam analysis (25 keV Bi3+) and depth profiling (20 keV with a distribution centered at Ar1500+) coupled to time of flight secondary ion mass spectrometry (3D-MSI-TOF-SIMS) for the study of A-172 human glioblastoma cell line treated with B-cell lymphoma 2 (Bcl-2) inhibitor ABT-737. The high spatial (~250 nm) and high mass resolution (m/Δm ~10,000) of TOF-SIMS permitted the localization and identification of the intact, unlabeled drug molecular ion (m/z 811.26 C42H44ClN6O5S2-[M - H]-) as well as characteristic fragment ions. We propose a novel approach based on the inspection of the drug secondary ion yield, which showed a good correlation with the drug concentration during cell treatment at therapeutic dosages (0-200 μM with 4 h incubation). Chemical maps using endogenous molecular markers showed that the ABT-737 is mainly localized in subsurface regions and absent in the nucleus. A semiquantitative workflow is proposed to account for the biological cell diversity based on the spatial distribution of endogenous molecular markers (e.g., nuclei and cytoplasm) and secondary ion confirmation based on the ratio of drug-specific fragments to molecular ion as a function of the therapeutic dosage. Graphical Abstract ᅟ.
authors: Department of Chemistry and Biochemistry, Florida International University, Miami, FL, USA.
authors: Quentin P
authors: QP
authors: Vanbellingen
authors: Department of Chemistry and Biochemistry, Florida International University, Miami, FL, USA.
authors: Anthony
authors: A
authors: Castellanos
authors: Department of Cellular Biology and Pharmacology, Department of Neuroscience, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA.
authors: Monica
authors: M
authors: Rodriguez-Silva
authors: Department of Cellular Biology and Pharmacology, Department of Neuroscience, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA.
authors: Iru
authors: I
authors: Paudel
authors: Department of Cellular Biology and Pharmacology, Department of Neuroscience, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA.|Biomolecular Science Institute, Florida International University, Miami, FL, USA.
authors: Jeremy W
authors: JW
authors: Chambers
authors: Department of Chemistry and Biochemistry, Florida International University, Miami, FL, USA. fernandf@fiu.edu.|Biomolecular Science Institute, Florida International University, Miami, FL, USA. fernandf@fiu.edu.
authors: Francisco A
authors: FA
authors: Fernandez-Lima
mesh_terms: D000970:Antineoplastic Agents / Q000008:administration & dosage*; D016503:Drug Delivery Systems; D006801:Humans; D007477:Ions; D018629:Spectrometry, Mass, Secondary Ion
chemical_list: D000970:Antineoplastic Agents; D007477:Ions
keywords: Chemical maps; Mass spectrometry imaging; Secondary ion mass spectrometry; Single cell analysis