Singletto Origins

Early in the COVID-19 pandemic, Singletto Co-Founder Dr. James (Jim) Chen hypothesized that Photodynamic Therapy (PDT) methods could be deployed for mask and Personal Protective Equipment (PPE) decontamination. PDT has long been deployed medically to treat cancer and skin disease. Chen, a neurosurgeon, has spent thirty years researching and applying various methods of PDT in diverse areas, including oncology, ophthalmology, dermatology, obesity, and for inflammatory conditions. As the world faced mask and PPE shortages, Chen’s hypothesis offered hope for healthcare and frontline workers being forced to reuse and extend the use of their single-use masks and PPE. The method also showed potential as a preventative measure to protect masks and PPE from becoming infected in the first place. Chen and Singletto Co-Founder and pediatric surgeon Dr. Thomas (Tom) Lendvay approached global health leaders who initiated worldwide research that confirmed the theory. Drs. Chen and Lendvay, together with John Bjornson and others, founded Singletto to further develop the technology to address the many unmet needs of healthcare, military, industry, and consumers.

Supporting Research

Drs. Lendvay and Chen and esteemed colleagues in a consortium of labs assembled through the World Health Organization (WHO) COVID-19 Task Force studied the PDT decontamination method, also referred to as Antimicrobial Photodynamic Inactivation (aPDI), on facemasks commonly used by healthcare and frontline workers. The aPDI method relies on light-activated protective dyes (PDs), such as Methylene Blue (MB), to induce an antimicrobial effect. Fifty-two researchers and 13 institutions, including the WHO, CDC, NIOSH, the University of Washington, George Washington University, and others, collaborated on this research. With Lendvay as Lead Author, the “Development of Methods for Mask and N95 Decontamination” (DeMaND) study was released in December 2020 and published in the Infection Control and Hospital Epidemiology peer-reviewed journal in 2021. The aPDI method was shown to “robustly and consistently inactivate” all three coronaviruses tested, including SARS-CoV-2, without compromising mask material integrity.

Further, masks and respirators pre-treated with the Methylene Blue protective dye provided ongoing inactivation of coronavirus. This is particularly important as SARS-CoV-2 has been shown to stay infective on a mask’s surface for up to seven days. Per Lendvay et al., 2021:

“Pretreatment of masks with MB could provide a novel means of continual decontamination reducing exposure to SARS-CoV-2 … [and] of continual inactivation of viral particles to decontaminate a mask while donned [i.e., worn].”

Follow-on DeMaND studies conducted in 2021 in partnership with the World Health Organization’s Global Research Forum were published in the American Journal of Infection Prevention (August 2022). These studies further demonstrate the novel application and antimicrobial power of aPDI technology against a wide variety of biological threats, including norovirus, coronaviruses, Ebola virus, Lassa virus, and Nipah virus. This body of peer-reviewed research further validates the aPDI method as a breakthrough decontamination and ongoing inactivation method. Not only can aPDI play a critical role in current pathogen protection, including the ongoing COVID-19 pandemic, but it can be an essential tool for protection against emerging threats of global interest and for future pandemic preparedness.