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Membrane interactions of antimicrobial peptide-loaded microgels

Nordström, Randi ; Browning, Kathryn L. ; Parra-Ortiz, Elisa ; Damgaard, Liv Sofia Elinor ; Häffner, Sara Malekkhaiat ; Maestro, Armando ; Campbell, Richard A. LU ; Cooper, Joshaniel F.K. and Malmsten, Martin LU (2020) In Journal of Colloid and Interface Science 562. p.322-332
Abstract

In the present study, lipid membrane interactions of anionic poly(ethyl acrylate-co-methacrylic acid) (MAA) microgels as carriers for the cationic antimicrobial peptide LL-37 (LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES) were investigated. In doing so, neutron reflectometry (NR), Fourier-transform infrared spectroscopy with attenuated total reflection (FTIR-ATR), zeta potential, ellipsometry, and circular dichroism spectroscopy (CD) experiments were employed to investigate the relative importance of membrane interactions of peptide-loaded microgel particles and of released peptide. For the free peptide, NR results showed membrane binding occurring preferentially in the tail region in a concentration-dependent manner. At low peptide... (More)

In the present study, lipid membrane interactions of anionic poly(ethyl acrylate-co-methacrylic acid) (MAA) microgels as carriers for the cationic antimicrobial peptide LL-37 (LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES) were investigated. In doing so, neutron reflectometry (NR), Fourier-transform infrared spectroscopy with attenuated total reflection (FTIR-ATR), zeta potential, ellipsometry, and circular dichroism spectroscopy (CD) experiments were employed to investigate the relative importance of membrane interactions of peptide-loaded microgel particles and of released peptide. For the free peptide, NR results showed membrane binding occurring preferentially in the tail region in a concentration-dependent manner. At low peptide concentration (0.3 μM) only peptide insertion in the outer leaflet was seen, however, pronounced membrane defects and peptide present in both leaflets was observed at higher peptide concentration (5.0 μM). LL-37 loaded into MAA microgels qualitatively mirrored these effects regarding both peptide localization within the membrane and concentration-dependent defect formation. In addition, very limited membrane binding of microgel particles was observed, in agreement with FTIR-ATR and liposome leakage results. FTIR-ATR showed LL-37 to undergo α-helix formation on membrane insertion, also supported by CD results, the kinetics of which was substantially reduced for microgel-loaded LL-37 due to sustained peptide release. Together, these findings demonstrate that membrane interactions for microgel-loaded LL-37 are dominated by released peptide, but also that slow release of microgel-loaded LL-37 translates into kinetic effects on peptide-membrane interactions, relating to both peptide localization within the bilayer, and to bilayer structure.

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author
; ; ; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Antimicrobial peptide, Bilayer, Membrane, Microgel, Neutron reflectometry
in
Journal of Colloid and Interface Science
volume
562
pages
11 pages
publisher
Elsevier
external identifiers
  • scopus:85076346710
  • pmid:31855795
ISSN
0021-9797
DOI
10.1016/j.jcis.2019.12.022
language
English
LU publication?
yes
id
52a17a55-b8eb-454b-af80-c1b4b7fb809b
date added to LUP
2021-01-05 10:54:11
date last changed
2022-05-24 03:32:23
@article{52a17a55-b8eb-454b-af80-c1b4b7fb809b,
  abstract     = {{<p>In the present study, lipid membrane interactions of anionic poly(ethyl acrylate-co-methacrylic acid) (MAA) microgels as carriers for the cationic antimicrobial peptide LL-37 (LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES) were investigated. In doing so, neutron reflectometry (NR), Fourier-transform infrared spectroscopy with attenuated total reflection (FTIR-ATR), zeta potential, ellipsometry, and circular dichroism spectroscopy (CD) experiments were employed to investigate the relative importance of membrane interactions of peptide-loaded microgel particles and of released peptide. For the free peptide, NR results showed membrane binding occurring preferentially in the tail region in a concentration-dependent manner. At low peptide concentration (0.3 μM) only peptide insertion in the outer leaflet was seen, however, pronounced membrane defects and peptide present in both leaflets was observed at higher peptide concentration (5.0 μM). LL-37 loaded into MAA microgels qualitatively mirrored these effects regarding both peptide localization within the membrane and concentration-dependent defect formation. In addition, very limited membrane binding of microgel particles was observed, in agreement with FTIR-ATR and liposome leakage results. FTIR-ATR showed LL-37 to undergo α-helix formation on membrane insertion, also supported by CD results, the kinetics of which was substantially reduced for microgel-loaded LL-37 due to sustained peptide release. Together, these findings demonstrate that membrane interactions for microgel-loaded LL-37 are dominated by released peptide, but also that slow release of microgel-loaded LL-37 translates into kinetic effects on peptide-membrane interactions, relating to both peptide localization within the bilayer, and to bilayer structure.</p>}},
  author       = {{Nordström, Randi and Browning, Kathryn L. and Parra-Ortiz, Elisa and Damgaard, Liv Sofia Elinor and Häffner, Sara Malekkhaiat and Maestro, Armando and Campbell, Richard A. and Cooper, Joshaniel F.K. and Malmsten, Martin}},
  issn         = {{0021-9797}},
  keywords     = {{Antimicrobial peptide; Bilayer; Membrane; Microgel; Neutron reflectometry}},
  language     = {{eng}},
  pages        = {{322--332}},
  publisher    = {{Elsevier}},
  series       = {{Journal of Colloid and Interface Science}},
  title        = {{Membrane interactions of antimicrobial peptide-loaded microgels}},
  url          = {{http://dx.doi.org/10.1016/j.jcis.2019.12.022}},
  doi          = {{10.1016/j.jcis.2019.12.022}},
  volume       = {{562}},
  year         = {{2020}},
}