Javascript is not activated in your browser. This website needs javascript activated to work properly.
You are here

Shape and Phase Transitions in a PEGylated Phospholipid System

  • Lauri Viitala
  • Saija Pajari
  • Luigi Gentile
  • Jukka Määttä
  • Marta Gubitosi
  • Jan Deska
  • Maria Sammalkorpi
  • Ulf Olsson
  • Lasse Murtomäki
Publishing year: 2019
Language: English
Pages: 3999-4010
Publication/Series: Langmuir
Volume: 35
Issue: 11
Document type: Journal article
Publisher: The American Chemical Society (ACS)

Abstract english

Poly(ethylene glycol) (PEG) polymers and PEG-conjugated lipids are widely used in bioengineering and drug transport applications. A PEG layer in a drug carrier increases hydrophilic repulsion, inhibits membrane fusion and serum opsonin interactions, and prolongs the storage and circulation time. It can also change the carrier shape and have an influence on many properties related to the content release of the carrier. In this paper, we focus on the physicochemical effects of PEGylation in the lipid bilayer. We introduce laurdanC as a fluorophore for shape recognition and phase transition detection. Together with laurdanC, cryogenic transmission electron microscopy, differential scanning calorimetry, molecular dynamics simulations, and small-angle X-ray scattering/wide-angle X-ray scattering, we acquire information of the particle/bilayer morphology and phase behavior in systems containing 1,2-dipalmitoyl-sn-glycero-3-phosphocholine:1,2-distearoyl-sn-glycero-3-phosphoethanolamine-PEG(2000) with different fractions. We find that PEGylation leads to two important and potentially usable features of the system. (1) Spherical vesicles present a window of elevated chain-melting temperatures and (2) lipid packing shape-controlled liposome-to-bicelle transition. The first finding is significant for targets requiring multiple release sequences and the second enables tuning the release by composition and the PEG polymer length. Besides drug delivery systems, the findings can be used in other smart soft materials with trigger-polymers as well.


  • Physical Chemistry
  • Polymer Chemistry


  • ISSN: 0743-7463
Luigi Gentile
E-mail: luigi [dot] gentile [at] fkem1 [dot] lu [dot] se




Sölvegatan 37, Lund


Visiting research fellow

Physical Chemistry

+46 46 222 45 04


Research group

Microbial Ecology