Effect of Shape on the Entering of Graphene Quantum Dots into a Membrane: A Molecular Dynamics Simulation

Abstract

Graphene quantum dots (GQDs), a new quasi-zero-dimensional nanomaterial, have the advantages of a smaller transverse size, better biocompatibility, and lower toxicity. They have potential applications in biosensors, drug delivery, and biological imaging. Therefore, it is particularly important to understand the transport mechanism of the GQDs on the cell membrane. In particular, the effect of the GQD shapes on the translocation mechanism should be well understood. In this study, the permeation process of the GQDs with different shapes through a 1-palmitoyl-2-oleoylphosphatidylcholine membrane was studied using molecular dynamics. The results show that all small-sized GQDs with different shapes translocated through the lipid membrane at a nanosecond timescale. The GQDs tend to remain on the surface of the cell membrane; then, the corners of the GQDs spontaneously enter the cell membrane; and, finally, the entire GQDs enter the cell membrane and tend to stabilize in the middle of the cell membrane. Moreover, the GQDs do not induce notable damage to the cell membrane, indicating that they are less toxic to cells and can be used as a potential biomedical material.

Cholesterols Induced Distinctive Entry of the Graphene Nanosheet into the Cell Membrane

“…Supplemental 300 ns animation is given in the Supporting Information. This result is similar to that of pristine graphene interacting with POPC bilayers. − …”

A review on synthesis, properties, and biomedical applications of graphene quantum dots (GQDs)

“…However, the criteria for GQDs' safe size can very between studies, making it somewhat unclear [171]. On the other hand, it is known that smaller GQDs have higher permeability through cell membranes and cause relatively minimal damage to the membranes [172,173]. This suggests that the low cell toxicity of smaller GQDs is related to their high membrane penetration and low level of membrane damage.…”

Advances in graphene-based 2D materials for tendon, nerve, bone/cartilage regeneration and biomedicine

“…used molecular dynamics simulations to investigate the transport mechanisms of GQD across cell membranes to interact with cell surfaces and lipids. 151 According to this simulation, the cells can automatically penetrate locally at the corners and prominences of the film, and then spontaneously diffuse along the edges of the graphene to complete the penetration. The other major mechanism of graphene is defined as the “oxidative stress” mode.…”