Quaternary Amine-Terminated Quantum Dots Induce Structural Changes to Supported Lipid Bilayers

Arielle C. Mensch, Joseph T. Buchman, Christy L. Haynes, Joel A. Pedersen, Robert J. Hamers

Research output: Contribution to journalArticlepeer-review

12 Scopus citations

Abstract

The cytoplasmic membrane represents an essential barrier between the cytoplasm and the environment external to cells. Interaction with nanomaterials can alter the integrity of the cytoplasmic membrane through the formation of holes and membrane thinning, which can ultimately lead to adverse biological impacts. Here we use supported lipid bilayers as experimental models for the cytoplasmic membrane to investigate the impact of quantum dots functionalized with the cationic polymer poly(diallyldimethylammonium chloride) (PDDA) on membrane structure. Using a quartz crystal microbalance with dissipation monitoring we show that the positively charged quantum dots attach to and induce structural rearrangement to zwitterionic bilayers in solely the liquid-disordered phase and in those containing phase-segregated liquid-ordered domains. Real-time atomic force microscopy imaging revealed that PDDA-coated quantum dots and, to a lesser extent, PDDA itself induced the disappearance of liquid-ordered domains. We hypothesize this effect is due to an increase in energy per unit area caused by collisions between PDDA-coated quantum dots at the membrane surface. This increase in free energy per area exceeds the approximate free-energy change associated with membrane mixing between the liquid-ordered and liquid-disordered phases and results in the destabilization of membrane domains.

Original languageEnglish (US)
Pages (from-to)12369-12378
Number of pages10
JournalLangmuir
Volume34
Issue number41
DOIs
StatePublished - Oct 16 2018

Bibliographical note

Funding Information:
This work was supported by the National Science Foundation under the Center for Sustainable Nanotechnology, CHE-1503408. The CSN is part of the Centers for Chemical Innovation Program. J.T.B. was supported by the National Science Foundation Graduate Research Fellowship under grant no. 00039202.

Publisher Copyright:
© 2018 American Chemical Society.

Fingerprint Dive into the research topics of 'Quaternary Amine-Terminated Quantum Dots Induce Structural Changes to Supported Lipid Bilayers'. Together they form a unique fingerprint.

Cite this