Probing molecular interactions of a phospholipid surfactant
Probing molecular interactions of a phospholipid surfactant
A synthetic phospholipid-based dry powder surfactant ‘PUMACTANT’ was found to obliterate the early phase asthmatic response when administered to mild asthmatics prior to bronchial provocation. A lipid electrospray tandem mass spectrometry (ESI-MS/MS) method was developed, which permitted analysis of pumactant turnover using deuteriated phospholipids. This was used to study the synthesis and turnover of surfactant phosphatidylcholine (PtdCho) substrate in healthy volunteers. Linear incorporation into PtdCho was observed over 30 hours peaking at 0.61% ± 0.04% between 30 and 48 hours. Incorporation decreased to 0.3 ± 0.02% within 7 days. The successful application of this technique to humans in vivo has paved the way for the study of exogenous surfactant lipid turnover in future clinical trials. Instrumentation was designed and manufactured to allow controlled dispensation of the very hygroscopic dry pumactant powder in order to study pumactant/surfactant interactions at air/liquid interfaces. The resulting custom built delivery device was capable of dispensing from microgram quantities to 87 ± 3 mg pumactant from a 100 mg vial. This device was used to dose pumactant onto aqueous subphases comprising endogenous surfactant combined with well known surfactant inhibitors under physiological conditions (37°C, 100% RH). The immunomodulatory properties of pumactant were screened using LacZ inducible antigen/MHC-specific T cell hybrids (B3Z cells). pumactant inhibited cellular activation in a dose dependent manner. Incubation of cells with deuteriated [methyl-d9]DPPC followed by ESI-MS/MS revealed a 37% metabolism of exogenous DPPC after 24 hours. Cells maintained tight regulation of membrane composition despite a 65 fold excess of exogenous DPPC to membrane PtdCho.
University of Southampton
Pynn, Christopher John
e85653cb-06b4-4c22-ab8a-94ae4ecbdd5d
2006
Pynn, Christopher John
e85653cb-06b4-4c22-ab8a-94ae4ecbdd5d
Pynn, Christopher John
(2006)
Probing molecular interactions of a phospholipid surfactant.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
A synthetic phospholipid-based dry powder surfactant ‘PUMACTANT’ was found to obliterate the early phase asthmatic response when administered to mild asthmatics prior to bronchial provocation. A lipid electrospray tandem mass spectrometry (ESI-MS/MS) method was developed, which permitted analysis of pumactant turnover using deuteriated phospholipids. This was used to study the synthesis and turnover of surfactant phosphatidylcholine (PtdCho) substrate in healthy volunteers. Linear incorporation into PtdCho was observed over 30 hours peaking at 0.61% ± 0.04% between 30 and 48 hours. Incorporation decreased to 0.3 ± 0.02% within 7 days. The successful application of this technique to humans in vivo has paved the way for the study of exogenous surfactant lipid turnover in future clinical trials. Instrumentation was designed and manufactured to allow controlled dispensation of the very hygroscopic dry pumactant powder in order to study pumactant/surfactant interactions at air/liquid interfaces. The resulting custom built delivery device was capable of dispensing from microgram quantities to 87 ± 3 mg pumactant from a 100 mg vial. This device was used to dose pumactant onto aqueous subphases comprising endogenous surfactant combined with well known surfactant inhibitors under physiological conditions (37°C, 100% RH). The immunomodulatory properties of pumactant were screened using LacZ inducible antigen/MHC-specific T cell hybrids (B3Z cells). pumactant inhibited cellular activation in a dose dependent manner. Incubation of cells with deuteriated [methyl-d9]DPPC followed by ESI-MS/MS revealed a 37% metabolism of exogenous DPPC after 24 hours. Cells maintained tight regulation of membrane composition despite a 65 fold excess of exogenous DPPC to membrane PtdCho.
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Published date: 2006
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Local EPrints ID: 466076
URI: http://eprints.soton.ac.uk/id/eprint/466076
PURE UUID: 7e1cb8a0-1fb1-41b5-ab97-ab7d9aa7086a
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Date deposited: 05 Jul 2022 04:14
Last modified: 16 Mar 2024 20:30
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Author:
Christopher John Pynn
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