Apr 11, 2014
Determining the translocation of nanoparticles
Understanding the factors determining the translocation of nanoparticles (NPs) across membranes is the key to designing versatile NPs for applications in nanotechnology and biomedicine. NP functionalization, for example coating with polymers or ligands, can directly change the NP-membrane interaction and open a way to control the NP cytotoxicity and translocation. Now, reporting in Nanotechnology, researchers at the Institute of Chemistry of the Chinese Academy of Sciences in China have revealed the important role of grafted polymers on the NP surface in its translocation through a fluidic membrane channel.
As carbon nanotubes (CNTs) are excellent water transporters, the researchers use all-atom molecular dynamics simulations to study the translocation of charged NPs through a fluidic CNT. A series of simulations are conducted for NPs with different polymer length, polymer number, charge amount and charge position. With the increase in polymer length, the NP flux decreases as a whole due to the increase in NP size. The negatively charged NP translocation fails at the smallest polymer length because of the strong binding of Na+.
Increasing the flux
Surprisingly, the NP flux exhibits a maximum with the increase of polymer number or charge amount, which is co-determined by the NP net charge and size. Owing to the NP-membrane adsorption and NP-ion binding, the NP flux decreases with the decrease of charge position.
Nanoparticle delivery applications
These results reveal the important role of grafted polymers in the NP translocation and may have implications in the design of highly efficient NP delivery. As in recent experiments, single NP translocation and detection has been achieved technically, so the researchers hope that their results can guide experimental researchers in the near future.
More information can be found in the journal Nanotechnology 25 185703.
About the author
Jiaye Su was an associated professor in Hongxia Guo’s group in the State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry Chinese Academy of Sciences. At present, he is a postdoc in Monica Olvera de la Cruz’s group in the department of Materials Science and Engineering, Northwestern University. His research focuses on molecular dynamics simulations of nanofluidics.