Diazirine reagents allow for the ready generation of carbenes upon photochemical, thermal, or electrical stimulation. Because carbenes formed in this way can undergo rapid insertion into any nearby C–H, O–H...
Motivated by a desire to develop flexible covalent adhesives that afford some of the same malleability in the adhesive layer as traditional polymer-based adhesives, we designed and synthesized two flexible,...
Electronically optimized bis-diazirine crosslinkers allow aliphatic polymers to be crosslinked with up to 10-fold improved efficacy, relative to earlier designs. Activation is achieved using modest temperatures or through UV or visible light.
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.
Antimicrobial photodynamic inactivation represents a
promising
and potentially greener alternative to conventional antimicrobials,
and a solution for multidrug-resistant strains. The current study
reports the development and characterization of tetra-substituted
diazirine porphyrin covalently bonded to polyethylene terephthalate
(PET) and its use as an antimicrobial surface. The diazirine moiety
on the porphyrin was activated using a temperature of 120 °C,
which initiated a C–H insertion mechanism that irreversibly
functionalized the PET surface. Activation of the surface with white
LED light in phosphate-buffered saline (PBS) led to singlet oxygen
generation, which was detected via the degradation of 9,10-anthracenediylbis(methylene)dimalonic
acid (ADMA) over time. The bactericidal effect of the
1
O
2
-producing surface against
Staphylococcus aureus
was determined qualitatively and quantitatively. The growth of the
pathogen beneath porphyrin-functionalized PET coupons was reduced;
moreover, the PET coupons resulted in a 1.76-log reduction in cell
counts after exposure to white LED light for 6 h. This is a promising
material and platform for the development of safer antimicrobial surfaces,
with applications in healthcare, food packaging, marine surfaces,
and other surfaces in the environment.
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