Insights into‎ Graphene Oxide Diffusion Mechanism along Cell Membranes

Chinese researchers have investigated the diffusive dynamics of graphene oxide (GO) ‎on the lipid bilayer of a cell membrane to develop new two-dimensional ‎nanocarriers. They showed that GO could be used to make nanocarriers, biosensors, ‎and electronic circuits in biological systems.‎

The cell membrane plays a significant role in cellular functioning, which manages ‎the flow of various materials and compounds into the cell. The membrane is made of ‎lipid bilayers within which nanoscale particles such as proteins are in a constant state ‎of motion. Understanding the diffusive dynamics of nanoparticles on the cell ‎membrane is essential for cellular functioning and immunity.

In recent years, some ‎studies have also been conducted on the co-delivery of medication and siRNA in the ‎cell aided by graphene oxide, which can be used in the gene therapy of cancer cells ‎and pathogens. In these researches, the transport of nanomaterials within the cell ‎membrane is a critical step. Hence, several models have been proposed to investigate ‎the diffusive transport of spheres or other three-dimensional nanoparticles on the cell ‎membrane; however, the transport of two-dimensional materials such as graphene and ‎transition-metal dichalcogenides is not well understood.

The researchers at the Tsinghua University, in collaboration with researchers from ‎several Chinese universities, examined the dynamics of the transport of two-‎dimensional nanomaterials on the cell membrane. They used graphene oxide (GO) ‎sandwiched inside the cell membranes to explore the behaviour of this two-‎dimensional nanostructure. This research group also simulated the translation or ‎diffusion dynamics of this nanomaterial.

They showed that the translational transport of GO sandwiched inside cell membranes ‎changes from Brownian to Lévy and even directional dynamics, governed by various ‎states of a sandwiched GO-induced pore in the leaflet of the membrane. Computer ‎simulations also confirm the diversity of the behaviour of GO in the cell membrane and ‎the relationship between the diffusion dynamics of GO and the pore structure. The ‎research group found that the pore induced by the entry of GO into the membrane can ‎be stable, unstable, or metastable. They believe that these results can be extended to ‎other two-dimensional nanomaterials.‎

But what is the application of this achievement? The researchers believe that the ‎results of this study could be used to design two-dimensional nanocarriers, which can ‎transport along the cell membrane for precision drug delivery. Considering the ‎importance of nanocarriers behavior and the need to increase their productivity and ‎efficiency, it is necessary to carefully examine their behaviour in a cellular environment ‎prior to the construction of nanocarriers to determine their functional ‎mechanism. These data can be used to increase the precision of drug delivery and the ‎stability of the nanocarriers on the path to the desired site.

Such superstructures could also be used as a platform for the development of ‎biosensors and electronic circuits where the lipid bilayer separates the sandwiched GO ‎from the electrically conducting media around it. Putting GO in the lipid environment ‎is a good opportunity to make biosensors, which allow the diagnosis of bioindicators. ‎Bioelectronics science is one of the most exciting topics that has been attracted to great ‎scientific consideration. Two-dimensional nanostructures that have been isolated ‎inside a living environment provides researchers with an excellent opportunity to use it ‎for bioelectronic development.‎

The results of this study have been published in the Science Advances journal with the ‎title of "Transport of a graphene nanosheet sandwiched inside cell membranes."‎