Catechol-Containing Polymer as Self-Activating Antipathogenic Coating

Exhaled breaths and coughs from patients with respiratory diseases is one of the major sources of airborne transmission. Respirators and face masks coated with a self-disinfecting coating that can be activated by the moisture found in respiratory droplets can potentially provide added protection to the wearer. Marine mussels secrete adhesive proteins that enable these organism to anchor themselves to various substrate (i.e., ship hull, rock) in a rough, intertidal zone. These mussel foot proteins contain a unique amino acid, L-3, 4 dihydroxyphenylalanine (DOPA), that is responsible for strong interfacial binding. Specifically, the catechol side chain of DOPA is capable of participating in reversible interactions and covalent crosslinking. Many investigators utilize the catechol as an adhesive moiety in designing biomimetic adhesives and coatings. In contrast to these applications, our lab has been developing antiviral and antimicrobial biomaterials utilizing the redox chemistry of catechol. Catechol generates reactive oxygen species (ROS), such as superoxide and hydrogen peroxide, when it becomes oxidized. The generated ROS was found to be antimicrobial against both gram-negative and gram-positive bacteria and reduced the infectivity of both non-enveloped and enveloped viruses. Most importantly, the generation of ROS can be easily activated by simple hydration of catechol-containing polymers and biomaterials. Most recently, we chemically modified catechol with an electron donating hydroxyl group (catechol-OH) to further enhance catechol’s ability to rapidly generate ROS. Polymer containing catechol-OH was coated onto polypropylene (PP) mesh, which is often used in the fabrication of disposable face masks and respirators. The ability for the coated PP mesh to generate antipathogenic levels of ROS using aerosolized droplets was investigated. Additionally, the ability for the catechol-coated mesh to inactivate aerosolized pathogens using human coronavirus (HCoV229E) as the model virus will be discussed.