(227g) Molecular Modeling of Nanoparticle Permeation in Lipid Membranes for Drug Delivery Applications

Permeation of small molecules through phospho-lipid bilayer membranes is a fundamental biological process that is important to understand in developing drug delivery applications. Nanoparticles have recently become important carriers for drug delivery in such therapeutic applications, in which drugs are encapsulated within nanoparticles. We describe coarse-grained simulation methods applicable to such large systems and use examples where the permeants are bare gold nanocrystals, gold-core nanoparticles with hydrophobic ligands (alkanethiol ligands of various lengths), and gold-core nanoparticles with hydrophilic ligands (methyl-terminated polyethylene glycol ligands of various lengths). In addition to spherical gold nanoparticles, we also examine the characteristic permeation mechanisms of the differently shaped gold nanorods with polyethylene glycol ligands, where the aspect ratio different from 1 makes the permeation event dependent on the angle of the nanorod axis relative to the membrane surface. Our results indicate that several phenomena accompany nanoparticle permeation including lipid flip-flop, water and ion penetration as well as lipid loss.

References

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