Investigating the\nSignificances of Thiol Functionalities\nin SARS-CoV‑2 Using Carbon Dots for Viral Inhibition

While the World Health Organization has declared the\nend of the\nSARS-CoV-2 public health emergency, studies related to corona viruses\nare still under course. As of 2024, the severity of COVID-19 has diminished\nwith current treatments and vaccinations. However, individuals can\nstill face severe complications, highlighting the importance of ongoing\nresearch into innovative treatments for current and future coronavirus-related\ndiseases. This study approaches the mechanism of viral entrance into\nthe host cells and the current evidence on the use of sulfhydryl groups\nfor the COVID-19 treatment. Certain thiol drugs, a key contributor\nto inflammatory processes, exhibit both viral inhibition properties\nand the potential to regulate cellular oxidative stress by scavenging\nfree radicals. Herein, we developed biocompatible thiol-functionalized\ncarbon dots (CDs) and investigated the correlation between the number\nof thiols and pseudo-SARS-CoV-2 inhibition, reactive oxygen species\n(ROS) scavenging, and anti-inflammatory response. The free-radical\nscavenging experiment and the ROS cellular assay indicate that thiolated\nCDs serve as effective reducing agents and potential regulators of\ncellular oxidative stress. The CDs also demonstrated good cell viability\nalongside significant antiviral capabilities, with inhibition levels\nup to 60.4%. Furthermore, the flow cytometry results suggest that\nin an inflammatory environment, the presence of thiolated CDs promotes\nan anti-inflammatory response. Overall, the results demonstrate a\nstrong correlation between the number of thiols and the increased\nefficacy observed across experiments, presenting thiolated CDs as\npromising candidates to prevent and treat COVID-19 infection.