Molecular mechanisms of interactions between BMP-2 and graphene: Effects of functional groups and microscopic morphology

Graphene and functionalized graphene are intensively studied as biomaterials for bone repair and regeneration. The interactions between graphene/functionalized graphene and key proteins implicated in bone repair are a key event for these applications, but the underlying mechanisms are insufficiently understood. Therefore, we performed molecular dynamics method to study the interactions between bone morphogenetic protein-2 (BMP-2) and perfect graphene, reduced graphene oxide, graphene oxide, and nitrogen functionalized graphene. Results indicated that, the surface modification with oxygen or nitrogen atoms can enhance the interactions between BMP-2 and those surfaces, as a result of the modified surface polarity. Of the four materials studied, graphene oxide was calculated to have the highest adsorption energy for BMP-2, as both the wrist and knuckle epitopes of this protein can interact with the graphene oxide due to its undulated surface morphology at molecular scales.