title: Fast surface acoustic wave-matrix-assisted laser desorption ionization mass spectrometry of cell response from islets of Langerhans.
abstract: A desire for higher speed and performance in molecular profiling analysis at a reduced cost is driving a trend in miniaturization and simplification of procedures. Here we report the use of a surface acoustic wave (SAW) atomizer for fast sample handling in matrix-assisted laser desorption ionization mass spectrometry (MALDI MS) peptide and protein profiling of Islets of Langerhans, for future type 2 diabetes (T2D) studies. Here the SAW atomizer was used for ultrasound (acoustic) extraction of insulin and other peptide hormones released from freshly prepared islets, stimulated directly on a membrane. A high energy propagating SAW atomizes the membrane-bound liquid into approximately 2 μm diameter droplets, rich in cell-released molecules. Besides acting as a sample carrier, the membrane provides a purification step by entrapping cell clusters and other impurities within its fibers. A new SAW-based sample-matrix deposition method for MALDI MS was developed and characterized by a strong insulin signal, and a limit of detection (LOD) lower than 100 amol was achieved. Our results support previous work reporting the SAW atomizer as a fast and inexpensive tool for ultrasound, membrane-based sample extraction. When interfaced with MALDI MS, the SAW atomizer constitutes a valuable tool for rapid cell studies. Other biomedical applications of SAW-MALDI MS are currently being developed, aiming at fast profiling of biofluids. The membrane sampling is a simplistic and noninvasive collection method of limited volume biofluids such as the gingival fluid and the tearfilm.
authors: Lund University, Center for Chemistry and Chemical Engineering, Pure and Applied Biochemistry, Box 124, 221 00 Lund, Sweden.
authors: Loreta
authors: L
authors: Bllaci
authors: Sven
authors: S
authors: Kjellström
authors: Lena
authors: L
authors: Eliasson
authors: James R
authors: JR
authors: Friend
authors: Leslie Y
authors: LY
authors: Yeo
authors: Staffan
authors: S
authors: Nilsson
mesh_terms: D000162:Acoustics; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000473:pathology; D005260:Female; D005456:Fluorescent Dyes / Q000737:chemistry; D007515:Islets of Langerhans / Q000166:cytology* / Q000378:metabolism / Q000473:pathology*; D057230:Limit of Detection; D051379:Mice; D053758:Nanoparticles / Q000737:chemistry; D015203:Reproducibility of Results; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D013499:Surface Properties
chemical_list: D015415:Biomarkers; D005456:Fluorescent Dyes