Effects of Mechanical Stress on the Formation of Pores in Lipid Membranes

MOYANO, MARIA S.; FERGUSON MICHAEL; BORIONI, JOSÉ L.; DEL PÓPOLO MARIO G.

Mendoza

Simposio; Symposium on Translational Medicine; 2019

Facultad de Ciencias Medicas - UNCuyo

Introduction:The mechanical properties of cells have been studied for centuries,with the intent to understand the underlying mechanical processesrequired to fulfil their basic functions.For many physiological processes, such as drug delivery and iontransport, the presence of defects, such as pores, in cell membranesis necessary. In the past decade, computer simulation hasdemonstrated itself to be a powerful tool in study of membranes andtheir defects.Objective:In this investigation we aim to use computational models to simulatethe behaviour of transient pores in lipid membranes, while in thevicinity of nano-bubbles.Methods:We use a classical, coarse-grained force field,MARTINI, to describe the molecular interactions found in the1,2-Dioleoyl-sn-glycero-3-phosphocholine(DOPC) lipid and water. Simulations of the lipid-water system areperformed using the molecular dynamics (MD) engine, LAMMPS. We usethe Plumed tool to create a bias in the simulations in order toinduce pore formation. Freely available, and self-developed tools areused to analyse the structural and energetic aspects of the simulatedsystems.Results:In our simulations we observe the reduction in local lipid densityupon the formation of pores. By comparing systems both in theabsence, and in the presence of a nano-bubble, we could betterunderstand the effects of said nano-bubble. We found that thepresence of a nano-bubble close to a lipid membrane led to areduction in the energy required to open a pore. In addition, thepore formed had a greater radius, and therefore volume, than thatformed in the absence of a nano-bubble. Conclusions:We conclude that further computational investigations surrounding theintroduction nano-bubbles into the vicinity of lipid membranes mayprovide us with the understanding of diverse new pathways forphysiological cell process.p { margin-bottom: 0.25cm; direction: ltr; line-height: 115%; text-align: left; orphans: 2; widows: 2; background: transparent }p.western { so-language: en-GB }