Molecular dynamics simulations of heat transfer in gold nanoparticle-lipid bilayer systems
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School of Chemical Technology | Licentiate thesis
77 + app. 11
AbstractNanoparticle-membrane interactions play a key role in many important applications such as drug delivery, nanomedicine, biosensors, electronic devices, imaging, diagnostics and cosmetics. Evidently, theoretical and experimental studies of nanoparticle and lipid bilayer interactions are major areas of research in the fields of soft matter and biophysical chemistry. However, complete understanding of these interactions with experimental methods can provide various scientific advances to bridge the gap between atomic level description of microscopic phenomenon and whole cell or system properties at various timescales. One such powerful technique in computational simulations is molecular dynamics (MD). In particular, here we adopt MD as a research tool for studying heat transfer characteristics of and results with reference to dipalmitoyl phosphatidylcholine (DPPC) lipid bilayer interacting with thiol functionalized 1) hydrophobic (hexane thiol ligand) and 2) hydrophilic (hydroxy pentane thiol ligand) gold nanoparticle heat source in presence of water. We demonstrate that, heat transfer MD simulations provide better qualitative understanding for the effect of nanoparticle position and type of ligand functionalization(s). Here, comparison of thermal conductivity and temperature distribution of both 1) hydrophobic nanoparticle (embedded inside membrane core) and 2) hydrophilic nanoparticle (placed in the proximity of bilayer heads and water) containing lipid bilayer system reveals that heat transfer in hydrophilic nanoparticle containing system is more efficient than in the system with hydrophobic nanoparticle. Additionally, heat transfer is asymmetric in such systems due to anisotropic nature of lipid bilayer. The findings discussed in this work may lead to a better understanding of heat transfer from heated gold nanoparticle source to lipid bilayer and of the light triggered release from GNP containing liposomes.
Thesis advisorSammalkorpi, Maria
molecular dynamics, gold nanoparticle, lipid bilayer