1. Translational feasibility and efficacy of nasal photodynamic disinfection of SARS-CoV-2.
- Author
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Pires, Layla, Wilson, Brian C., Bremner, Rod, Lang, Amanda, Larouche, Jeremie, McDonald, Ryan, Pearson, Joel D., Trcka, Daniel, Wrana, Jeff, Wu, James, and Whyne, Cari M.
- Subjects
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SARS-CoV-2 , *METHYLENE blue , *BACTERIAL inactivation , *PHOTODYNAMIC therapy , *BETACORONAVIRUS , *VACCINE effectiveness - Abstract
The lack of therapeutic options to fight Covid-19 has contributed to the current global pandemic. Despite the emergence of effective vaccines, development of broad-spectrum antiviral treatment remains a significant challenge, in which antimicrobial photodynamic therapy (aPDT) may play a role, especially at early stages of infection. aPDT of the nares with methylene blue (MB) and non-thermal light has been successfully utilized to inactivate both bacterial and viral pathogens in the perioperative setting. Here, we investigated the effect of MB-aPDT to inactivate human betacoronavirus OC43 and SARS-CoV-2 in vitro and in a proof-of-principle COVID-19 clinical trial to test, in a variety of settings, the practicality, technical feasibility, and short-term efficacy of the method. aPDT yielded inactivation of up to 6-Logs in vitro, as measured by RT-qPCR and infectivity assay. From a photo-physics perspective, the in vitro results suggest that the response is not dependent on the virus itself, motivating potential use of aPDT for local destruction of SARS-CoV-2 and its variants. In the clinical trial we observed variable effects on viral RNA in nasal-swab samples as assessed by RT-qPCR attributed to aPDT-induced RNA fragmentation causing falsely-elevated counts. However, the viral infectivity in clinical nares swabs was reduced in 90% of samples and undetectable in 70% of samples. This is the first demonstration based on quantitative clinical viral infectivity measurements that MB-aPDT is a safe, easily delivered and effective front-line technique that can reduce local SARS-CoV-2 viral load. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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