News & Events

When

Date - February 15, 2019
1:00 pm - 2:00 pm

What

Dr. Reza A. Ghiladi
Associate Professor of Chemistry
Department of Chemistry
NC State University
Talk Title: Photosensitizer-Modified Polymers as Anti-infective Materials: From Nanofibers to Textiles

Abstract:

The transmission of pathogens from improperly sterilized surfaces poses an escalating risk to human health. Towards our overall objective of developing potent antimicrobial materials to combat this threat, we have focused on photoactive materials in which porphyrin-based photosensitizers have been tethered or embedded to either cellulose nanocrystals (Photochem. Photobiol. 2012, 88, 527-536), cellulose fibers (Biomacromolecules 2015, 16, 2482-2492), polyacrylonitrile nanofibers (Nanomaterials 2016, 6, 77), or olefinic block copolymers (ACS Appl. Mater. Interfaces 2018, 10, 25955–25959). As an example, paper sheets comprised of cellulose-porphyrin fibers were found to be highly effective in mediating the photodynamic inactivation of pathogens: S. aureus, A. baumannii, P. aeruginosa and K. pneumonia all exhibited inactivation by 99.99+%, as well as inactivation of dengue-1 virus (>99.995%), influenza A (~99.5%), and human adenovirus-5 (~99%). As an alternative strategy, we have embedded a cationic porphyrin into polyacrylonitrile nanofibers using electrospinning, and demonstrated that this non-covalent approach is highly effective at mediating both antibacterial and antiviral activities. More recently, we have prepared photosensitizer-embedded olefinic block copolymers using melt-pressing, and demonstrated that this non-covalent strategy is able to produce highly antimicrobial materials against a range of microbes, including Gram-positive and Gram-negative drug-resistant bacterial strains, as well as antiviral activity against enveloped and non-enveloped viruses. Such materials may have widespread applicability for the elimination of a wide range of pathogens, and may lead to their application in hospitals and healthcare-related industries where novel materials capable of reducing pathogen transmission, particularly for antibiotic resistant strains, is desired.