Glycyrrhizic‐Acid‐Based Carbon Dots with High Antiviral Activity by Multisite Inhibition Mechanisms

Abstract

With the gradual usage of carbon dots (CDs) in the area of antiviral research, attempts have been stepped up to develop new antiviral CDs with high biocompatibility and antiviral effects. In this study, a kind of highly biocompatible CDs (Gly‐CDs) is synthesized from active ingredient (glycyrrhizic acid) of Chinese herbal medicine by a hydrothermal method. Using the porcine reproductive and respiratory syndrome virus (PRRSV) as a model, it is found that the Gly‐CDs inhibit PRRSV proliferation by up to 5 orders of viral titers. Detailed investigations reveal that Gly‐CDs can inhibit PRRSV invasion and replication, stimulate antiviral innate immune responses, and inhibit the accumulation of intracellular reactive oxygen species (ROS) caused by PRRSV infection. Proteomics analysis demonstrates that Gly‐CDs can stimulate cells to regulate the expression of some host restriction factors, including DDX53 and NOS3, which are directly related to PRRSV proliferation. Moreover, it is found that Gly‐CDs also remarkably suppress the propagation of other viruses, such as pseudorabies virus (PRV) and porcine epidemic diarrhea virus (PEDV), suggesting the broad antiviral activity of Gly‐CDs. The integrated results demonstrate that Gly‐CDs possess extraordinary antiviral activity with multisite inhibition mechanisms, providing a promising candidate for alternative therapy for PRRSV infection.

An overview of functional nanoparticles as novel emerging antiviral therapeutic agents

“…As shown in the results, one-step heating of curcumin at 180°C preserves many of the moieties of polymeric curcumin on the surfaces of the as-synthesized Cur-CQDs, resulting in superior antiviral characteristics. Later, our group has developed a new type of highly biocompatible carbon quantum dots (Gly-CDs) with glycyrrhizic acid (an active ingredient of Chinese herbal medicine) using a hydrothermal method, and the as-prepared Gly-CDs were shown to inhibit the proliferation of PRRSV by up to 5 orders of viral titers [52]. Further investigations reveal that Gly-CDs can inhibit PRRSV invasion and replication, stimulate antiviral innate immune responses, and suppress the accumulation of intracellular reactive oxygen species (ROS) caused by PRRSV infection.…”

Quantum dots as a promising agent to combat COVID‐19

“…[29] Similarly, the Gly-CDs derived from glycyrrhizic acid exerted excellent antiviral properties by suppressing the propagation of porcine reproductive and respiratory syndrome virus. [30] In addition, the use of conventional biocompounds (e.g. curcumin) in the synthesis of QDs can offer a suitable choice of antiviral agents.…”

Nano-based antiviral coatings to combat viral infections

“…Functional carbon dots as antiviral agents: Several antiviral therapeutics are recently being developed around the World, based on carbon dots or carbon quantum dots, initially discovered for its colorful and bright fluorescence resembling the conventional semiconductor quantum dots [49] , [53] , [54] , [55] .…”

“…In a more recent study, Tong et al. investigated the effect of Glycyrrhizic acid-based carbon dots(Gly-CDs) upon the invasion potential of PSRRV(Porcine reproductive and respiratory syndrome virus) using African green monkey kidney(Vero) and Porcine Kidney(PK-15) cells [55] . Through TEM, they concluded that Gly-CDs could directly interact with the PSRRVs, adding to the virus’s reduced infectivity due to Gly-CD treatment.…”

“…performed molecular docking model studies to track and understand the interactions between IONPs (iron oxide nanoparticles: Fe 2 O 3 and Fe 3 O 4 ) and spike protein of SARS-CoV2 [104] . Recent investigations using a genius amalgamation of strategies targeting various aspects of viral biology, as well as their mode of action has resulted in the development of novel therapeutic approaches that have helped in better management of viral infections [55] , [81] , [82] , [87] , [89] . As mentioned earlier, technologies like photodynamic inhibition, although were known to humankind since the last century, have only been recently used in developing PDI based antiviral technologies that have proved to be highly effective [42] .…”