Covalent functionalization of polypropylene filters with diazirine–photosensitizer conjugates producing visible light driven virus inactivating materials

Abstract

The SARS-CoV-2 pandemic has highlighted the weaknesses of relying on single-use mask and respirator personal protective equipment (PPE) and the global supply chain that supports this market. There have been no major innovations in filter technology for PPE in the past two decades. Non-woven textiles used for filtering PPE are single-use products in the healthcare environment; use and protection is focused on preventing infection from airborne or aerosolized pathogens such as Influenza A virus or SARS-CoV-2. Recently, C–H bond activation under mild and controllable conditions was reported for crosslinking commodity aliphatic polymers such as polyethylene and polypropylene. Significantly, these are the same types of polymers used in PPE filtration systems. In this report, we take advantage of this C–H insertion method to covalently attach a photosensitizing zinc-porphyrin to the surface of a melt-blow non-woven textile filter material. With the photosensitizer covalently attached to the surface of the textile, illumination with visible light was expected to produce oxidizing 1O2/ROS at the surface of the material that would result in pathogen inactivation. The filter was tested for its ability to inactivate Influenza A virus, an enveloped RNA virus similar to SARS-CoV-2, over a period of four hours with illumination of high intensity visible light. The photosensitizer-functionalized polypropylene filter inactivated our model virus by 99.99% in comparison to a control.

Multifunctional Carbon Fibers from Chemical Upcycling of Mask Waste

“… 12 , 13 Additionally, Menon et al demonstrated that post-functionalization of PP masks can result in effective sterilization through the use of zinc porphyrin photosensitizers for enhancing the ability of the masks to protect against influenza pathogens. 14 Alternatively, masks can be collected and recycled through several processing steps, such as granulation and pelletization. While such mechanical recycling methods have been established in industry, they often result in downgraded material properties and a less valuable product due to increased yellowness and reduced melt viscosity from possible chain scission under high shear.…”

Electronically optimized diazirine-based polymer crosslinkers

“…19 Diazirine reagents can also add functionality to commodity polymers; 20 for example porphyrin conjugate 8 can be used to generate antiviral coatings on woven polypropylene filter material. 21 The aryl diazirines discussed above range from moderately electron rich (3) to moderately electron poor (1 and 6), with the majority being electron neutral. This raises an important but unaddressed question: what kind of aryl diazirine is preferred in order to maximize the efficacy of polymer crosslinking?…”

Light-Induced Anti-Bacterial Effect Against Staphylococcus aureus of Porphyrin Covalently Bonded to a Polyethylene Terephthalate Surface

“…Recently, the use of a tetra-substituted diazirine porphyrin covalently bonded to nonwoven melt-blown polypropylene textiles was demonstrated by our group to be efficient for virus inactivation. 45 Here, we explore the use of the diazirine photosensitizer for greener and potentially more effective prevention and treatment of bacteria on polyethylene terephthalate (PET).…”