Continuous-time binding kinetics of graphene oxide quantum dots and lipid bilayers dominated by hydrogen bonding: effect of nanoparticles' protein corona and membrane components

Elucidating the interaction mechanism between nanomaterials and cell membranes is critical for cytotoxicity mechanisms and the design of safer biomedicines. Recently, graphene oxide quantum dots (GOQDs) were shown to induce disruption in the cell membrane. Little is known, however, about why this occurs and what microscopic interactions are important. Here, we investigate the continuous-time interaction of model cell membrane with GOQDs via atomic force microscopy/surface plasmon resonance. The binding of particles to the model membranes is a concentration-dependent and reversible process, which is significantly hampered by cholesterol, ganglioside GM1 and protein corona. In addition, the molecular mechanism of GOQD-cell membrane interaction is analyzed using molecular dynamics simulation: GOQDs attach rapidly to the surface of the cell membrane and then induce the deformation of lipid bilayers, subsequently physically extracting lipid molecules, particularly cholesterol and ganglioside GM1. Hydrogen bonding plays a dominant role in the interaction of GOQDs and the membrane, which is mainly derived from the hydroxyl, carbonyl and phosphate groups of membranes. These findings might have implications in studies of the cytotoxicity of nanomaterials and in novel biomedicine design. Binding of graphene oxide quantum dots to model membranes is hampered by cholesterol, ganglioside GM1 and protein corona, which is dominated by hydrogen bonding. This study might have implications in studies of the nanotoxicity at atomic resolution.