title: Label-free real-time acoustic sensing of microvesicle release from prostate cancer (PC3) cells using a Quartz Crystal Microbalance.
abstract: Using a Quartz Crystal Microbalance with dissipation monitoring, QCM-D (label-free system) measuring changes in resonant frequency (Δf) that equate to mass deposited on a sensor, we showed the attachment, over a 60min period, of a monolayer of PC3 cells to the gold electrodes of the quartz crystal sensor, which had been rendered hydrophilic. That MVs were released upon BzATP stimulation of cells was confirmed by NTA analysis (average 250nm diameter), flow cytometry, showing high phosphatidylserine exposition and by fluorescent (Annexin V Alexa Fluor® 488-positive) and electron microscopy. Over a period of 1000s (16.7min) during which early apoptosis increased from 4% plateauing at 10% and late apoptosis rose to 2%, the Δf increased 20Hz, thereupon remaining constant for the last 1000s of the experiment. Using the Sauerbrey equation, the loss in mass, which corresponded to the release of 2.36×10(6)MVs, was calculated to be 23ng. We therefore estimated the mass of an MV to be 0.24pg. With the deposition on the QCM-D of 3.5×10(7)MVs over 200s, the decrease in Δf (Hz) gave an estimate of 0.235pg per MV.
authors.affiliation: Cellular and Molecular Immunology Research Centre, School of Human Sciences, London Metropolitan University, London, UK.
authors.forename: Dan
authors.initials: D
authors.lastname: Stratton
authors.affiliation: University College London School of Pharmacy, 29-39 Brunswick Square, London WC1N 1AX, UK.
authors.forename: Sigrun
authors.initials: S
authors.lastname: Lange
authors.affiliation: Cellular and Molecular Immunology Research Centre, School of Human Sciences, London Metropolitan University, London, UK.
authors.forename: Sharad
authors.initials: S
authors.lastname: Kholia
authors.affiliation: Cellular and Molecular Immunology Research Centre, School of Human Sciences, London Metropolitan University, London, UK.
authors.forename: Samireh
authors.initials: S
authors.lastname: Jorfi
authors.affiliation: Cellular and Molecular Immunology Research Centre, School of Human Sciences, London Metropolitan University, London, UK.
authors.forename: Samuel
authors.initials: S
authors.lastname: Antwi-Baffour
authors.affiliation: Cellular and Molecular Immunology Research Centre, School of Human Sciences, London Metropolitan University, London, UK. Electronic address: j.inal@londonmet.ac.uk.
authors.forename: Jameel
authors.initials: J
authors.lastname: Inal
mesh_terms: D000162:Acoustics; D045744:Cell Line, Tumor; D005434:Flow Cytometry; D006801:Humans; D008297:Male; D008854:Microscopy, Electron; D011471:Prostatic Neoplasms / Q000473:pathology*; D011791:Quartz
chemical_list: D011791:Quartz
keywords: Microvesicles; Prostate cancer cells (PC3); Quartz Crystal Microbalance; Real-time analysis; Stimulated release