A quantitative determination of lipid bilayer deposition efficiency using AFM

Research output: Contribution to journalArticlepeer-review

Authors

  • Mary Wood
  • David C. Milan
  • Richard J. Nichols
  • Michael T.L. Casford
  • Sarah L. Horswell

Colleges, School and Institutes

External organisations

  • University of Liverpool
  • University of Cambridge

Abstract

The efficacy of a number of different methods for depositing a dimyristoylphosphatidylcholine (DMPC) lipid bilayer or DMPC-cholesterol (3 : 1) mixed bilayer onto a silicon substrate has been investigated in a quantitative manner using atomic force microscopy (AFM) image analysis to extract surface coverage. Complementary AFM-IR measurements were used to confirm the presence of the lipids. For the Langmuir-Blodgett/Schaefer deposition method at temperatures below the chain-melting transition temperature (Tm), a large number of bilayer defects resulted when DMPC was deposited from a water subphase. Addition of calcium ions to the trough led to smaller, more frequent defects, whereas addition of cholesterol to the lipid mixture led to a vast improvement in bilayer coverage. Poor coverage was achieved for deposition at temperatures aboveTm. Formation of the deposited bilayer from vesicle fusion proved a more reliable method for all systems, with formation of near-complete bilayers within 60 seconds at temperatures aboveTm, although this method led to a higher probability of multilayer formation and rougher bilayer surfaces.

Bibliographic note

Funding Information: This work was funded by a Leverhulme Trust Research Project Grant (grant number RPG-2016-158). Publisher Copyright: © The Royal Society of Chemistry 2021.

Details

Original languageEnglish
Pages (from-to)19768-19778
Number of pages11
JournalRSC Advances
Volume11
Issue number32
Early online date2 Jun 2021
Publication statusE-pub ahead of print - 2 Jun 2021