RESUMEN
BACKGROUND: Since effective antiviral drugs for COVID-19 are still limited in number, the exploration of compounds that have antiviral activity against SARS-CoV-2 is in high demand. Porphyrin is potentially developed as a COVID-19 antiviral drug. However, its low solubility in water restricts its clinical application. Reconstruction of porphyrin into carbon dots is expected to possess better solubility and bioavailability as well as lower biotoxicity. METHODS AND RESULTS: In this study, we investigated the antiviral activity of porphyrin and porphyrin-derived carbon dots against SARS-CoV-2. Through the in silico analysis and assessment using a novel drug screening platform, namely dimer-based screening system, we demonstrated the capability of the antivirus candidates in inhibiting the dimerization of the C-terminal domain of SARS-CoV-2 Nucleocapsid. It was shown that porphyrin-derived carbon dots possessed lower cytotoxicity on Vero E6 cells than porphyrin. Furthermore, we also assessed their antiviral activity on the SARS-CoV-2-infected Vero E6 cells. The transformation of porphyrin into carbon dots substantially augmented its performance in disrupting SARS-CoV-2 propagation in vitro. CONCLUSIONS: Therefore, this study comprehensively demonstrated the potential of porphyrin-derived carbon dots to be developed further as a promisingly safe and effective COVID-19 antiviral drug.
RESUMEN
Even entering the third year of the COVID-19 pandemic, only a small number of COVID-19 antiviral drugs are approved. Curcumin has previously shown antiviral activity against SARS-CoV-2 nucleocapsid, but its poor bioavailability limits its clinical uses. Utilizing nanotechnology structures, curcumin-derived carbon-dots (cur-CDs) were synthesized to increase low bioavailability of curcumin. In-silico analyses were performed using molecular docking, inhibition of SARS-CoV-2 nucleocapsid C-terminal domain (N-CTD) and antiviral activity were assessed in dimer-based screening system (DBSS) and in vitro respectively. Curcumin bound with the N-CTD at ΔG = -7.6 kcal/mol, however modifications into cur-CDs significantly improved the binding affinity and %interaction. Cur-CDs also significantly increased protection against SARS-CoV-2 in both DBSS and in vitro at MOI = 0.1. This study demonstrated the effect of post-infection treatment of curcumin and novel curcumin-derived carbon-dots on SARS-CoV-2 N-CTD dimerization. Further investigation on pre-infection and in-vivo treatment of curcumin and cur-CDs are required for a comprehensive understanding on the carbon-dots enhanced antiviral activity of curcumin against SARS-CoV-2.
RESUMEN
Cervical cancer caused by Human papillomavirus (HPV) is one of the most common causes of cancer death in women worldwide. Even though the disease can be avoided by immunization, the expensive price of HPV vaccines makes it hard to be accessed by women in middle-low-income countries. Thus, the development of generic HPV vaccines is needed to address inequalities in life-saving access. This study aimed to develop the HPV52 L1 VLP-based recombinant vaccine using Pichia pastoris expression system. The l1 gene was codon-optimized based on P. pastoris codon usage resulting CAI value of 0.804. The gene was inserted into the pD902 plasmid under the regulation of the AOX1 promoter. The linear plasmid was transformed into P. pastoris BG10 genome and screened in YPD medium containing zeocin antibiotic. Colony of transformant that grown on highest zeocin concentration was characterized by genomic PCR and sequencing. The positive clone was selected and expressed using BMGY/BMMY medium induced with various methanol concentrations. The SDS-PAGE and Western blot analyses showed that 55 kDa L1 protein was successfully expressed using an optimum concentration of 1% methanol. The self-assembly of HPV52 L1 protein was also proven using TEM analysis. Moreover, we also analyzed the B-cell epitope of HPV52 L1 protein based on several criteria, including antigenicity, surface accessibility, flexibility, and hydrophilicity. We assumed that epitope 476GLQARPKLKRPASSAPRTSTKKKKV500 could be developed as an epitope-based vaccine with a neutralizing antibody response toward HPV52 infection. Finally, our study provided the alternative for developing low-cost HPV vaccines, either VLP or epitope-based.