Ultrasound induced fluorescence of nanoscale liposome contrast agents

A new imaging contrast agent is reported that provides an increased fluorescent signal upon application of ultrasound (US). Liposomes containing lipids labelled with pyrene were optically excited and the excimer fluorescence emission intensity was detected in the absence and presence of an ultrasoun...

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Main Authors: Zhang, Qimei, Morgan, Stephen P., O’Shea, Paul, Mather, Melissa L.
Format: Article
Published: Public Library of Science 2016
Online Access:https://eprints.nottingham.ac.uk/46412/
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author Zhang, Qimei
Morgan, Stephen P.
O’Shea, Paul
Mather, Melissa L.
author_facet Zhang, Qimei
Morgan, Stephen P.
O’Shea, Paul
Mather, Melissa L.
author_sort Zhang, Qimei
building Nottingham Research Data Repository
collection Online Access
description A new imaging contrast agent is reported that provides an increased fluorescent signal upon application of ultrasound (US). Liposomes containing lipids labelled with pyrene were optically excited and the excimer fluorescence emission intensity was detected in the absence and presence of an ultrasound field using an acousto-fluorescence setup. The acousto-fluorescence dynamics of liposomes containing lipids with pyrene labelled on the fatty acid tail group (PyPC) and the head group (PyPE) were compared. An increase in excimer emission intensity following exposure to US was observed for both cases studied. The increased intensity and time constants were found to be different for the PyPC and PyPE systems, and dependent on the applied US pressure and exposure time. The greatest change in fluorescence intensity (130%) and smallest rise time constant (0.33 s) are achieved through the use of PyPC labelled liposomes. The mechanism underlying the observed increase of the excimer emission intensity in PyPC labelled liposomes is proposed to arise from the “wagging” of acyl chains which involves fast response and requires lower US pressure. This is accompanied by increased lipid lateral diffusivity at higher ultrasound pressures, a mechanism that is also active in the PyPE labelled liposomes.
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spelling nottingham-464122020-05-04T17:59:25Z https://eprints.nottingham.ac.uk/46412/ Ultrasound induced fluorescence of nanoscale liposome contrast agents Zhang, Qimei Morgan, Stephen P. O’Shea, Paul Mather, Melissa L. A new imaging contrast agent is reported that provides an increased fluorescent signal upon application of ultrasound (US). Liposomes containing lipids labelled with pyrene were optically excited and the excimer fluorescence emission intensity was detected in the absence and presence of an ultrasound field using an acousto-fluorescence setup. The acousto-fluorescence dynamics of liposomes containing lipids with pyrene labelled on the fatty acid tail group (PyPC) and the head group (PyPE) were compared. An increase in excimer emission intensity following exposure to US was observed for both cases studied. The increased intensity and time constants were found to be different for the PyPC and PyPE systems, and dependent on the applied US pressure and exposure time. The greatest change in fluorescence intensity (130%) and smallest rise time constant (0.33 s) are achieved through the use of PyPC labelled liposomes. The mechanism underlying the observed increase of the excimer emission intensity in PyPC labelled liposomes is proposed to arise from the “wagging” of acyl chains which involves fast response and requires lower US pressure. This is accompanied by increased lipid lateral diffusivity at higher ultrasound pressures, a mechanism that is also active in the PyPE labelled liposomes. Public Library of Science 2016-07-28 Article PeerReviewed Zhang, Qimei, Morgan, Stephen P., O’Shea, Paul and Mather, Melissa L. (2016) Ultrasound induced fluorescence of nanoscale liposome contrast agents. PLoS ONE, 11 (7). e0159742/1-e0159742/15. ISSN 1932-6203 http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0159742 doi:10.1371/journal.pone.0159742 doi:10.1371/journal.pone.0159742
spellingShingle Zhang, Qimei
Morgan, Stephen P.
O’Shea, Paul
Mather, Melissa L.
Ultrasound induced fluorescence of nanoscale liposome contrast agents
title Ultrasound induced fluorescence of nanoscale liposome contrast agents
title_full Ultrasound induced fluorescence of nanoscale liposome contrast agents
title_fullStr Ultrasound induced fluorescence of nanoscale liposome contrast agents
title_full_unstemmed Ultrasound induced fluorescence of nanoscale liposome contrast agents
title_short Ultrasound induced fluorescence of nanoscale liposome contrast agents
title_sort ultrasound induced fluorescence of nanoscale liposome contrast agents
url https://eprints.nottingham.ac.uk/46412/
https://eprints.nottingham.ac.uk/46412/
https://eprints.nottingham.ac.uk/46412/