Mild adsorption of carbon nitride (C3N3) nanosheet on a cellular membrane reveals its suitable biocompatibility

Abstract

Recently, the novel hole-containing carbon nitride C3N3 nanomaterial was successfully synthesized, featuring outstanding and unique mechanical and electrical properties. However, to fully exploit this nanomaterial in biomedical applications, information regarding its biocompatibility is necessary. Herein, by using all-atom molecular dynamics simulations, we evaluate the interactions between a C3N3 nanosheet and a critical cellular component, that is, a lipid membrane bilayer. Our results indicate that the C3N3 nanosheet is able to interact with the lipid bilayer surface without affecting the membrane’s structural integrity. Moreover, our results showed that the C3N3 nanosheet is adsorbed on the surface of the lipid bilayer without inflicting any structural damage to the membrane, regardless of the conditions of the system (that is, with and without restrains in the C3N3 nanosheet). Also, we found that both energy contributions, namely vdW and Coulomb energies, conjointly mediated the C3N3 adsorption process. In comparison and as expected, pristine graphene significantly disturbed the membrane structure. Perpendicularly-oriented-sheet simulations described the significance of the surface charges of the C3N3 nanosheet in prohibiting its insertion into the membrane. Detailed analysis indicated that the electrostatic attraction between the pores in the C3N3 structure and the lipid head amino groups stabilized the interaction restricting the insertion of the C3N3 structure deeper into the membrane. Our results suggested the importance of the negatively charged C3N3 pores when interacting with lipid membranes. Our findings shed light on the potential compatibility of C3N3 with biomembranes and its underlying molecular mechanism, which might provide a useful foundation for the future exploration of this 2D nanomaterial in biomedical applications.