The emerging area of carbon-based nanoparticles (NPs) and their increased usage in the biomedicalfield necessitate checking their biocompatibility and permeation pathway across the cell membrane. In thisstudy, we explore the permeation pathway of two NPs - a well-studied fullerene (C60) and a pristine carbon dot(CD) across a model Palmitoyloleoylphosphatidylcholine (POPC) lipid membrane. Both constrained andunconstrained all-atom molecular dynamics (MD) simulations are carried out to understand their permeationmechanism. C60 permeates the bilayer via passive permeation and stays inside the hydrophobic core, while theCDdoes not show any sign of permeation across the membrane throughout the simulation time window. The freeenergy profiles for the permeation are calculated using the umbrella sampling method. The huge barrier for thepermeation of theCDis confirmed from thePMFprofiles, while the free energy minima for the permeation of C60 are located in the bilayer interior. This mode of permeation of C60 can hint at its toxic nature to cell membraneswidely investigated in the past. The structural properties of the bilayer are also analyzed, and on a global scale, itshows no significant mechanical damage to the membrane. Thus, our study details the molecular level interactionof pristine carbon-based NPs with a lipid bilayer.
In this work, we explored the permeation pathway of two hydrophobic carbon nanoparticles (NPs) - fullerene (C60) and carbon dot (CD) across a lipid bilayer. We assessed the free energy profile for the permeation, partition coefficient, permeability coefficient, and effects of the nanoparticles on the membrane structure.
Volume 133, 2021
Continuous Article Publishing mode
Click here for Editorial Note on CAP Mode