Science & Evidence Behind Oxafence
Antimicrobial Photodynamic Inactivation (aPDI) refers to the application of well-studied photodynamic principles to microbial control. Photodynamic Therapy (PDT) has been used clinically for decades in diverse medical contexts, and aPDI adapts those principles for microbial interactions with materials. At its core, aPDI involves light-activated protective dyes that interact with surrounding oxygen to generate short-lived reactive oxygen species, most notably singlet oxygen, at the surface where they are applied.
Singlet oxygen is:
widely studied in chemistry and biology
produced naturally in the environment (e.g., through plant and atmospheric interactions)
understood to interact with microbes at the molecular level
short-lived and localized in action
This fundamental science provides the basis for Oxafence technology.
Watch the 3-minute overview to see how light-activated dyes generate singlet oxygen and how this process interacts with viruses at the surface level.
Applying This Science to Masks
Before 2020, most people rarely thought about how masks work. As respiratory protection became part of everyday life, many found that the available information was often technical, fragmented, or developed for specialized settings, such as clinical environments or industrial applications.
Many of the questions we first had while studying mask design mirror what we now hear from others, such as:
How do masks capture particles that are smaller than the spaces between fibers?
What happens to viruses after they are captured?
How do filtration, fit, and real-world use interact?
These questions reflect core principles in aerosol science, filtration, and materials design. To share what we’ve learned in a more accessible way, we created a resource called the Mask Hub – a resource we wish had been available when we first starting asking these same questions.
Protective Dyes Used in Oxafence
Oxafence formulations incorporate medically understood protective dyes, including Methylene Blue (MB) and Riboflavin (Vitamin B2).
Methylene Blue (MB)
Has a long history of use in medicine, including as a textile dye, surgical marking agent, and therapeutic compound.
Is on the World Health Organization’s list of essential medicines.
When incorporated into materials and exposed to ambient light, participates in singlet oxygen generation.
Riboflavin (Vitamin B2)
A naturally occurring nutrient that also acts as a photosensitizer in aPDI contexts.
Can be integrated similarly into materials to support light-activated reactions.
Taken together, these protective dyes form the basis of Oxafence’s materials-applied scientific approach.
Peer-Reviewed Research & WHO-Linked Studies
Singletto’s scientific foundation is rooted in clinician-led research organized through global collaborations, including work with members of a World Health Organization task force during the COVID-19 pandemic.
The Development of Methods for Mask and N95 Decontamination (DeMaND) study, co-authored by Singletto leadership and international partners, was published in Infection Control and Hospital Epidemiology (2021) and explored mask-based applications of aPDI under relevant use conditions.
Subsequent research was published in the American Journal of Infection Control (2022), including studies led by Singletto co-founder Dr. Thomas Lendvay examining Methylene Blue–based approaches, CDC-researcher–led studies involving high-consequence pathogens such as Ebola, Nipah, and Lassa viruses, and a PPE usage study that included participation from Singletto scientific advisors.
These peer-reviewed studies provide detailed methodology, experimental context, and analysis of how light-activated dye interactions were evaluated in controlled research settings.
Ongoing Research & Collaboration
Singletto’s scientists, virologists, chemists, and clinical collaborators continue to engage with U.S. Military, academic, and institutional partners on expanding the evidence base for materials-applied photodynamic approaches.
This body of work includes contributions from multiple institutions and seeks to broaden understanding of how these principles can interface with materials science, virology, and regulatory pathways.
For the most up-to-date listings of peer-reviewed research, publications, and conference proceedings, consult the journal links above or contact the Singletto science team directly.