Size-dependent interactions between graphene quantum dots and multidrug resistance protein (MDR-1)

MDR-1, a cellular efflux protein responsible for the transport of drugs and other pharmaceutical therapies, is known to increase resistance to chemotherapeutics in tumor cells. This hyperactivity reduces the efficacy of cancer treatment displaying a need to discover avenues of inhibition or downregulation of MDR-1. A more broadly effective potential substrate is the graphene quantum dot (GQD), which has been identified as a single inhibitor affecting multiple transporters associated with drug resistance. This study analyzed the interactions of three different-sized GQDs with MDR-1 using molecular dynamics to understand the effect of GQD size on the adsorption of MDR-1. Several stability and energy analyses indicated an optimal GQD size of 5 × 6 nm based on the information from the number of salt bridges, Van der Waals energy and the ratio of polar to hydrophobic amino acids pointing out that this GQD size is the optimal modulatory substrate for MDR-1.