Calcium dependent reversible aggregation of Escherichia coli biomimicking vesicles enables formation of supported vesicle layers on silicon dioxide

Filip Dusa, Wen Chen, Joanna Witos, Susanne Kristina Wiedmer

Research output: Contribution to journalArticleScientificpeer-review

Abstract

The importance of using biomimicking membranes for various biological applications is rising, as such models are relevant for imitating real organisms. In addition, biomimicking membranes are usually much more repeatable in preparation and easier to handle during analysis than real organisms or biological membranes. In this work, we developed a method for the adsorption of intact small unilamellar Escherichia coli (E. cols) vesicles (Z-average size of 73 nm) on SiO2 substrate material. We describe the adsorption process based on the use of two surface sensitive techniques, i.e., nanoplasmonic sensing (NPS) and quartz crystal microbalance (QCM). The acquired data show that the adsorption follows a two-step process. The first step is a slow adsorption of E coil vesicle aggregates held together by 5 mM of calcium (Z-average size of 531 nm). The Z-average of the aggregates decreased almost three times when the calcium concentration was decreased to 0.1 mM. This suggests that the aggregates were disassembling to some extent when calcium was removed from the system. With both techniques, i.e., NPS and QCM, we observed a second rapid adsorption step after the solution was changed to deionized water. In this second step, the aggregates started to fall apart as the calcium concentration dropped, and the released vesicles started to adsorb onto unoccupied spots at the SiO2 surface of the sensors. Extensive release of mass from the surface was confirmed by QCM, where it was reflected by a sharp increase of frequency, while NPS, due to its lower sensing depth of a few tens of nanometers, did not record such a change. Taken together, we have developed a protocol to form a supported vesicle layer (SVL) of E coli vesicles on SiO2 surface using sodium 4-(2-hydroxyethyppiperazine-1-ethanesulfonate buffer, thus enabling the preparation of E coli biomimicking SVLs for interaction studies of compounds of interest. The immobilization happens via a two-step adsorption process.
Original languageEnglish
Article number23
JournalFrontiers in materials
Volume6
Number of pages8
ISSN2296-8016
DOIs
Publication statusPublished - 1 Mar 2019
MoE publication typeA1 Journal article-refereed

Fields of Science

  • aggregation
  • biomembrane
  • Escherichia coli
  • nanoplasmonic sensing
  • vesicles
  • quartz crystal microbalance
  • ANIONIC LIPOSOMES
  • CARDIOLIPIN
  • MEMBRANE
  • DEFORMATION
  • ADSORPTION
  • BACTERIAL
  • BILAYERS
  • CATIONS
  • MODEL
  • 116 Chemical sciences

Cite this

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title = "Calcium dependent reversible aggregation of Escherichia coli biomimicking vesicles enables formation of supported vesicle layers on silicon dioxide",
abstract = "The importance of using biomimicking membranes for various biological applications is rising, as such models are relevant for imitating real organisms. In addition, biomimicking membranes are usually much more repeatable in preparation and easier to handle during analysis than real organisms or biological membranes. In this work, we developed a method for the adsorption of intact small unilamellar Escherichia coli (E. cols) vesicles (Z-average size of 73 nm) on SiO2 substrate material. We describe the adsorption process based on the use of two surface sensitive techniques, i.e., nanoplasmonic sensing (NPS) and quartz crystal microbalance (QCM). The acquired data show that the adsorption follows a two-step process. The first step is a slow adsorption of E coil vesicle aggregates held together by 5 mM of calcium (Z-average size of 531 nm). The Z-average of the aggregates decreased almost three times when the calcium concentration was decreased to 0.1 mM. This suggests that the aggregates were disassembling to some extent when calcium was removed from the system. With both techniques, i.e., NPS and QCM, we observed a second rapid adsorption step after the solution was changed to deionized water. In this second step, the aggregates started to fall apart as the calcium concentration dropped, and the released vesicles started to adsorb onto unoccupied spots at the SiO2 surface of the sensors. Extensive release of mass from the surface was confirmed by QCM, where it was reflected by a sharp increase of frequency, while NPS, due to its lower sensing depth of a few tens of nanometers, did not record such a change. Taken together, we have developed a protocol to form a supported vesicle layer (SVL) of E coli vesicles on SiO2 surface using sodium 4-(2-hydroxyethyppiperazine-1-ethanesulfonate buffer, thus enabling the preparation of E coli biomimicking SVLs for interaction studies of compounds of interest. The immobilization happens via a two-step adsorption process.",
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author = "Filip Dusa and Wen Chen and Joanna Witos and Wiedmer, {Susanne Kristina}",
year = "2019",
month = "3",
day = "1",
doi = "10.3389/fmats.2019.00023",
language = "English",
volume = "6",
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Calcium dependent reversible aggregation of Escherichia coli biomimicking vesicles enables formation of supported vesicle layers on silicon dioxide. / Dusa, Filip; Chen, Wen; Witos, Joanna; Wiedmer, Susanne Kristina.

In: Frontiers in materials, Vol. 6, 23, 01.03.2019.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Calcium dependent reversible aggregation of Escherichia coli biomimicking vesicles enables formation of supported vesicle layers on silicon dioxide

AU - Dusa, Filip

AU - Chen, Wen

AU - Witos, Joanna

AU - Wiedmer, Susanne Kristina

PY - 2019/3/1

Y1 - 2019/3/1

N2 - The importance of using biomimicking membranes for various biological applications is rising, as such models are relevant for imitating real organisms. In addition, biomimicking membranes are usually much more repeatable in preparation and easier to handle during analysis than real organisms or biological membranes. In this work, we developed a method for the adsorption of intact small unilamellar Escherichia coli (E. cols) vesicles (Z-average size of 73 nm) on SiO2 substrate material. We describe the adsorption process based on the use of two surface sensitive techniques, i.e., nanoplasmonic sensing (NPS) and quartz crystal microbalance (QCM). The acquired data show that the adsorption follows a two-step process. The first step is a slow adsorption of E coil vesicle aggregates held together by 5 mM of calcium (Z-average size of 531 nm). The Z-average of the aggregates decreased almost three times when the calcium concentration was decreased to 0.1 mM. This suggests that the aggregates were disassembling to some extent when calcium was removed from the system. With both techniques, i.e., NPS and QCM, we observed a second rapid adsorption step after the solution was changed to deionized water. In this second step, the aggregates started to fall apart as the calcium concentration dropped, and the released vesicles started to adsorb onto unoccupied spots at the SiO2 surface of the sensors. Extensive release of mass from the surface was confirmed by QCM, where it was reflected by a sharp increase of frequency, while NPS, due to its lower sensing depth of a few tens of nanometers, did not record such a change. Taken together, we have developed a protocol to form a supported vesicle layer (SVL) of E coli vesicles on SiO2 surface using sodium 4-(2-hydroxyethyppiperazine-1-ethanesulfonate buffer, thus enabling the preparation of E coli biomimicking SVLs for interaction studies of compounds of interest. The immobilization happens via a two-step adsorption process.

AB - The importance of using biomimicking membranes for various biological applications is rising, as such models are relevant for imitating real organisms. In addition, biomimicking membranes are usually much more repeatable in preparation and easier to handle during analysis than real organisms or biological membranes. In this work, we developed a method for the adsorption of intact small unilamellar Escherichia coli (E. cols) vesicles (Z-average size of 73 nm) on SiO2 substrate material. We describe the adsorption process based on the use of two surface sensitive techniques, i.e., nanoplasmonic sensing (NPS) and quartz crystal microbalance (QCM). The acquired data show that the adsorption follows a two-step process. The first step is a slow adsorption of E coil vesicle aggregates held together by 5 mM of calcium (Z-average size of 531 nm). The Z-average of the aggregates decreased almost three times when the calcium concentration was decreased to 0.1 mM. This suggests that the aggregates were disassembling to some extent when calcium was removed from the system. With both techniques, i.e., NPS and QCM, we observed a second rapid adsorption step after the solution was changed to deionized water. In this second step, the aggregates started to fall apart as the calcium concentration dropped, and the released vesicles started to adsorb onto unoccupied spots at the SiO2 surface of the sensors. Extensive release of mass from the surface was confirmed by QCM, where it was reflected by a sharp increase of frequency, while NPS, due to its lower sensing depth of a few tens of nanometers, did not record such a change. Taken together, we have developed a protocol to form a supported vesicle layer (SVL) of E coli vesicles on SiO2 surface using sodium 4-(2-hydroxyethyppiperazine-1-ethanesulfonate buffer, thus enabling the preparation of E coli biomimicking SVLs for interaction studies of compounds of interest. The immobilization happens via a two-step adsorption process.

KW - aggregation

KW - biomembrane

KW - Escherichia coli

KW - nanoplasmonic sensing

KW - vesicles

KW - quartz crystal microbalance

KW - ANIONIC LIPOSOMES

KW - CARDIOLIPIN

KW - MEMBRANE

KW - DEFORMATION

KW - ADSORPTION

KW - BACTERIAL

KW - BILAYERS

KW - CATIONS

KW - MODEL

KW - 116 Chemical sciences

U2 - 10.3389/fmats.2019.00023

DO - 10.3389/fmats.2019.00023

M3 - Article

VL - 6

JO - Frontiers in materials

JF - Frontiers in materials

SN - 2296-8016

M1 - 23

ER -