Plant Cell-Engineered Gold Nanoparticles Conjugated to Quercetin Inhibit SARS-CoV-2 and HSV-1 Entry

Abstract

Recent studies have revealed considerable promise in the antiviral properties of metal nanomaterials, specifically when biologically prepared. This study demonstrates for the first time the antiviral roles of the plant cell-engineered gold nanoparticles (pAuNPs) alone and when conjugated with quercetin (pAuNPsQ). We show here that the quercetin conjugated nanoparticles (pAuNPsQ) preferentially inhibit the cell entry of two medically important viruses—severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and herpes simplex virus type-1 (HSV-1) using different mechanisms. Interestingly, in the case of SARS-CoV-2, the pre-treatment of target cells with pAuNPsQ inhibited the viral entry, but the pre-treatment of the virus with pAuNPsQ did not affect viral entry into the host cell. In contrast, pAuNPsQ demonstrated effective blocking capabilities against HSV-1 entry, either during the pre-treatment of target cells or by inducing virus neutralization. In addition, pAuNPsQ also significantly affected HSV-1 replication, evidenced by the plaque-counting assay. In this study, we also tested the chemically synthesized gold nanoparticles (cAuNPs) of identical size and shape and observed comparable effects. The versatility of plant cell-based nanomaterial fabrication and its modification with bioactive compounds opens a new frontier in therapeutics, specifically in designing novel antiviral formulations.

Flavonoids with Anti-Herpes Simplex Virus Properties: Deciphering Their Mechanisms in Disrupting the Viral Life Cycle

“…The nanoparticles boost drug solubility, prolong circulation time, and target specific cells, ensuring a focused approach that minimizes potential side effects in treating HSV diseases [80,81]. Elste et al [82] conducted a study illustrating the potent antiviral capacity of plant cell-engineered gold nanoparticles conjugated with quercetin (pAuNPsQ) against HSV-1. These formulated nanoparticles effectively inhibit HSV-1 entry and replication through various mechanisms.…”