Antiviral potential of graphitic carbon nitride (g-C3N4) nanosheets against herpes simplex virus type 1

Herpes Simplex Virus Type 1 (HSV-1) has been found to present many therapeutic challenges due to the problem of drug resistance and the low efficacy of antiviral compounds. Recently, the photocatalytic property and biocompatibility of graphitic carbon nitride (g-C 3 N 4 ) nanosheets have been found to be promising for antiviral therapy. The antiviral efficacy and biocompatibility of the g-C 3 N 4 nanosheets are assessed in this study. g-C 3 N 4 nanosheets were prepared and characterized by X-ray diffraction (XRD), Fourier Transform InfraRed Spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), and zeta potential measurements to confirm the properties. Antiviral efficacy was determined by the ability of g-C 3 N 4 to block the infection of Vero cells by HSV-1 using two different methods: the virucidal assay and the post-treatment assay. The Real-Time PCR measured viral replication. The cytotoxic effect of the g-C 3 N 4 nanosheets was evaluated using a neutral red uptake assay. g-C 3 N 4 nanosheets exhibited a pure graphitic structure, high colloidal stability, and a porous, flake-like morphology. They achieved dose-dependent HSV-1 inhibition rates of 94.9–99.2% (virucidal) and 92.3–96.0% (post-treatment) at 600–800 µg/mL ( P < 0.001). No cytotoxic effects were seen in the g-C 3 N 4 nanosheets; however, increased cell viability by nearly 40% was seen when tested at a concentration of 800 µg/mL. g-C 3 N 4 nanosheets possess excellent biocompatibility and the ability to inhibit HSV-1 greatly, and are promising alternatives to conventional treatment regimens. There is a need to study further the mechanism of the antiviral properties of g-C 3 N 4 nanosheets and the efficacy of g-C 3 N 4 nanosheets in vivo.