Designing Porphyrinic Covalent Organic Frameworks for the Photodynamic Inactivation of Bacteria

Abstract

Microbial colonization of biomedical devices is a recognized complication contributing to healthcare-associated infections. One of the possible approaches to prevent surfaces from the biofilm formation is antimicrobial photodynamic inactivation based on the cytotoxic effect of singlet oxygen, O(Δ), a short-lived, highly oxidative species, produced by energy transfer between excited photosensitizers and molecular oxygen. We synthesized porphyrin-based covalent organic frameworks (COFs) by Schiff-base chemistry. These novel COFs have a three-dimensional, diamond-like structure. The detailed analysis of their photophysical and photochemical properties shows that the COFs effectively produce O(Δ) under visible light irradiation, and especially three-dimensional structures have strong antibacterial effects toward Pseudomonas aeruginosa and Enterococcus faecalis biofilms. The COFs exhibit high photostability and broad spectral efficiency. Hence, the porphyrinic COFs are suitable candidates for the design of antibacterial coating for indoor applications.

Rejuvenated Photodynamic Therapy for Bacterial Infections

“…Classical PSs are poorly soluble and easily aggregate under physiological conditions, which seriously restrict their clinical efficacy for PDAT . In this regard, several nanostructured self‐assemblies have been developed based on classical PSs with significant improvements in their PDAT applications .…”

Porphyrin‐Based Porous Organic Frameworks as Oxygen Reservoirs to Overcome Tumor Hypoxia for Enhanced Photodynamic Therapy

“…[14] The limitations of hypoxia and PDT can be overcome by choosing porous organic frameworks (POFs). [21] www.advancedsciencenews.com www.advtherap.com Scheme 1. [15] Therefore, POFs have promising applications in gas storage and separation, [16] catalysis, [17] energy, [18] and sensors.…”

“…[20] Moreover, a limited number of POFs materials have been first explored for PDT. [21] Scheme 1. Schematic representation for the preparation of the TAPP-B4-POFs, the subsequent O 2 loading, and application in the PDT.…”

Recent Trends in Covalent and Metal Organic Frameworks for Biomedical Applications

“…These COFs (COF-SDU1 and COFs-Trif-Benz) were effective against Escherichia coli (gram-negative) and Staphylococcus aureus (gram-positive). The most prominent example of COF-based photodynamic inactivation was recently reported by Hynek and coworkers [ 135 ]. They designed a 3D porphyrin-based COF that effectively generated singlet oxygen under visible-light irradiation at intensities as low as 1 mW cm −2 , and killed resistant Enterococcus faecalis (a gram-positive facultative anaerobe) as well as Pseudomonas aeruginosa (a gram-negative aerobe).…”