Molecular dynamics simulations of rupture in lipid bilayers

Michael D. Tomasini, Carlos Rinaldi, M. Silvina Tomassone

Research output: Contribution to journalArticle

26 Scopus citations

Abstract

Magnetic fluid hyperthermia is a promising cancer therapy in which magnetic nanoparticles are acted upon by a high-frequency oscillating magnetic field. While the accepted mechanism is localized hyperthermia, it is plausible that shear stresses due to nanoparticles rotating near a cell membrane may induce rupture, enhancing the effectiveness of the treatment. With the goal of understanding this further, molecular dynamics simulations were carried out on a model cell membrane. A bilayer composed of dipalmitoylphosphatidylcholine lipids was subjected to an incremental tension as well as an incremental shear stress. In both cases, it was found that the bilayer could withstand a surface tension of approximately 90 mN/m prior to rupture. Under tension, the bilayer ruptured at double its initial area, whereas under shear, the bilayer ruptured at 1.8 times its initial area. The results show that both incremental tension and incremental shearing are able to produce bilayer rupture, with shear being more injurious, yielding a larger surface tension for a smaller deformation. This information allows for comparison between the estimated energy required to rupture a cell membrane and the energy that a magnetic nanoparticle would be able to generate while rotating in a cellular environment. Our estimates indicate that magnetically blocked nanoparticles with diameters larger than 50 nm may result in rupture due to shear.

Original languageEnglish (US)
Pages (from-to)181-188
Number of pages8
JournalExperimental Biology and Medicine
Volume235
Issue number2
DOIs
StatePublished - Feb 1 2010

All Science Journal Classification (ASJC) codes

  • Biochemistry, Genetics and Molecular Biology(all)

Keywords

  • Lipid bilayer
  • Magnetic fluid hyperthermia
  • Molecular dynamics simulation
  • Shear stress

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