Translocation mechanism of anticancer drugs through membrane with the assistance of graphene quantum dot.

In recent years, as a new type of quasi-zero-dimensional nanomaterials, graphene quantum dots (GQDs) have shown excellent performance in advanced drug targeted delivery and controlled release. In this work, the delivery process of model drugs translocating into POPC lipid membrane with the assistance of GQDs was investigated via molecular dynamics (MD) simulation. Our simulation results demonstrated that a single doxorubicin (DOX) or deoxyadenine (DA) molecule is difficult to penetrate into the cell membrane. GQD7 could form sandwich-like structure with DOX and assist DOX to enter into the POPC membrane. However, due to the weak interaction with DA, both GQD7 and GQD19 can not assist DA translocating the POPC membrane in the limited MD simulation time. The drug delivery process for DOX could be divided into two steps: 1. GQDs and DOX aggregated into a cluster; 2. the aggregates enter into the POPC membrane. In all our simulation systems, if GQDs loaded with model drugs and entered the cell membrane, it had little effect on the cell membrane structure, and the cell membrane could maintain high integrity and stability. These results may promote the molecular design and application of GQD-based drug delivery systems.