Journal: International Journal of Molecular Sciences

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

doi: 10.3390/ijms241914792

Figure Lengend Snippet: Synthesis of plant cell derived gold nanoparticles (pAuNPs). Medicago sativa (Alfalfa) in vitro plantlets were established (panel ( A )) followed by the callus mass (panel ( B )) to generate cell suspension culture (panel ( C )). Upon feeding the cell suspension culture with the salts of KAuCl4 resulted in the formation of gold nanoparticles (panel ( D )). The gold nanoparticles were separated from the cell suspension culture using sonication and centrifugation. The extracted gold nanoparticles were further purified by the sephadex G100 column (panel ( E )). The coating of plant cell-derived gold nanoparticles with quercetin is described in .

Article Snippet: A chemically synthesized amine functional group capped with gold spherical nanoparticles (cAuNPs; 20–22 nm size) was purchased from Nanopartz.

Techniques: Derivative Assay, In Vitro, Suspension, Sonication, Centrifugation, Purification

Journal: International Journal of Molecular Sciences

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

doi: 10.3390/ijms241914792

Figure Lengend Snippet: Characterization of plant cell derived gold nanoparticles (pAuNPs) with and without quercetin. The images showing the characterization of nanoparticles were carried out by measuring optical density under UV-visible spectrophotometer in presence and absence of quercetin (panels ( A , B )). The characterization of nanoparticles for the particle size and distribution in the presence and absence of quercetin (panels ( C , D )) is shown.

Article Snippet: A chemically synthesized amine functional group capped with gold spherical nanoparticles (cAuNPs; 20–22 nm size) was purchased from Nanopartz.

Techniques: Derivative Assay, Spectrophotometry

Journal: International Journal of Molecular Sciences

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

doi: 10.3390/ijms241914792

Figure Lengend Snippet: Characterization of plant cell derived gold nanoparticles (pAuNPs) with and without quercetin. The images show the characterization of nanoparticles for the zeta potential by Dynamic Light Scattering (DLS) in presence and absence of quercetin (panels ( A , B )) instrument in a triplicate experiment. Further, the analysis of functional groups present in the plant cell-engineered gold nanoparticles with and without quercetin was carried out by Fourier-transform infrared spectroscopy (FITR; panels ( C , D )).

Article Snippet: A chemically synthesized amine functional group capped with gold spherical nanoparticles (cAuNPs; 20–22 nm size) was purchased from Nanopartz.

Techniques: Derivative Assay, Functional Assay, Spectroscopy

Journal: International Journal of Molecular Sciences

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

doi: 10.3390/ijms241914792

Figure Lengend Snippet: The effect of plant cell derived gold nanoparticle (pAuNPs) and chemically synthesized gold nanoparticles (cAuNPs) conjugated with and or without quercetin on the cellular toxicity using LDH assay. ( A ). HEK-293T cells that stably express ACE-2 receptors were incubated in the presence or absence of the nanoparticles (NPs) at 20 µg/mL and 10 µg/mL for 48 h to mimic the conditions used during SARS-CoV-2 cell entry. ( B ). HeLa cells were incubated in the presence and absence of NPs at 10 µg/mL and 20 µg/mL for 6 h to mimic the conditions used during the HSV-1 cell entry. The cells treated with media alone represent the spontaneous LDH release (min LDH), while cells lysed with detergent represent maximum LDH release. Asterisks (****) indicate a significant difference between the maximum LDH release and the nanoparticle-treated cells ( p < 0.0001).

Article Snippet: A chemically synthesized amine functional group capped with gold spherical nanoparticles (cAuNPs; 20–22 nm size) was purchased from Nanopartz.

Techniques: Derivative Assay, Synthesized, Lactate Dehydrogenase Assay, Stable Transfection, Incubation

Journal: International Journal of Molecular Sciences

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

doi: 10.3390/ijms241914792

Figure Lengend Snippet: Pretreatment of target cells with pAuNPsQ and cAuNPsQ affects SARS-CoV-2 pseudovirus cell entry, but pretreatment of pseudovirus does not affect cell entry. ( A ). Monolayers of HEK-293T cells were preincubated with pAuNPs or cAuNPs with or without quercetin at 10 µg/mL and 20 µg/mL before transducing the target cells with SARS-CoV-2 (D614G) pseudovirus. ( B ). SARS-CoV-2 pseudovirus was pre-treated with 10 µg/mL or 20 µg/mL of gold nanoparticles followed by transduction of the target cell with the nanoparticle-treated pseudovirus. The untreated HEK293T-ACE2 cells transduced or infected with the SARS-CoV-2 pseudovirus were considered as a positive control (+), while the un-transduced HEK293T-ACE2 cells were considered as a negative control (−). Asterisks indicate a significant difference between the positive control and the cells treated with AuNPs (**** p < 0.0001, *** p < 0.0003, “ns” indicates not significant).

Article Snippet: A chemically synthesized amine functional group capped with gold spherical nanoparticles (cAuNPs; 20–22 nm size) was purchased from Nanopartz.

Techniques: Transduction, Infection, Positive Control, Negative Control

Journal: International Journal of Molecular Sciences

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

doi: 10.3390/ijms241914792

Figure Lengend Snippet: Pretreatment of target cells and HSV-1 with pAuNPsQ and cAuNPsQ significantly impairs herpes simplex virus type-1 (HSV-1) cell entry. ( A ). HeLa cells were preincubated with pAuNPs and cAuNPs with or without quercetin at 10 µg/mL and 20 µg/mL followed by infection with HSV-1 (gL86). ( B ). HSV-1 was pre-incubated with 10 µg/mL and or 20 µg/mL of gold nanoparticles followed by infection of the target HeLa cell with the nanoparticle-treated virus. ( C ). The dose-response curve generated for the determination of IC 50 values of pAuNPsQ and cAuNPsQ against herpes simplex virus type-1 entry. In all viral entry experiments, the untreated HeLa cells infected with the HSV-1 were considered as a positive control (+), while the uninfected HeLa cells were considered as a negative control (−). Asterisks indicate a significant difference between the positive control and the cells treated with AuNPs (* p ≤ 0.05, *** p ≤ 0.0001, **** p ≤ 0.0001, ns not significant).

Article Snippet: A chemically synthesized amine functional group capped with gold spherical nanoparticles (cAuNPs; 20–22 nm size) was purchased from Nanopartz.

Techniques: Virus, Infection, Incubation, Generated, Positive Control, Negative Control

Journal: International Journal of Molecular Sciences

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

doi: 10.3390/ijms241914792

Figure Lengend Snippet: Possible mechanism by which plant cell derived gold nanoparticles conjugated to quercetin (pAuNPsQ) inhibits virus–host cell interactions. ( A ) Quercetin-conjugated gold nanoparticles block HSV-1 entry by interacting with the HSV-1 entry glycoprotein and/or targeting host cell receptors, as evident from our virus neutralization and cell pre-treatment assays (sub panel ( a )). Since multiple viral glycoproteins and host cell receptors are involved in facilitating HSV-1 entry, the actions by pAuNPsQ could be predicted to be pleiotropic in nature, having an affinity for one or more HSV-1 envelope virus glycoproteins (gB, gD, gH-gL) as well as for one or more host cell receptors. In contrast, quercetin-conjugated gold nanoparticles did not affect SARAS-CoV-2 neutralization, while pre-treatment with quercetin conjugated gold nanoparticles inhibited SARS-CoV-2 entry suggesting the possible interactions between pAuNPsQ with the host cell surface ACE2 receptor (sub panel ( b )). ( B ) The proposed development of virus-specific gold nanoparticles can be generated by conjugating pAuNPsQ to the virus-specific anti-envelope glycoprotein D (gD) peptides in case for HSV-1 (sub panel ( a )). Similarly conjugating pAuNPs to anti-spike envelope proteins could be used for the development of robust anti-SARS-CoV-2 agent (sub panel ( b )). In addition, tagging quercetin-based gold nanoparticles with anti-host cell receptor peptides (anti-heparan sulfate or anti-ACE2) can equally be tailored for their antiviral activity against specific viruses.

Article Snippet: A chemically synthesized amine functional group capped with gold spherical nanoparticles (cAuNPs; 20–22 nm size) was purchased from Nanopartz.

Techniques: Derivative Assay, Virus, Blocking Assay, Neutralization, Generated, Activity Assay