Revisiting Current Photoactive Materials for Antimicrobial Photodynamic Therapy

Abstract

Microbial infection is a severe concern, requiring the use of significant amounts of antimicrobials/biocides, not only in the hospital setting, but also in other environments. The increasing use of antimicrobial drugs and the rapid adaptability of microorganisms to these agents, have contributed to a sharp increase of antimicrobial resistance. It is obvious that the development of new strategies to combat planktonic and biofilm-embedded microorganisms is required. Photodynamic inactivation (PDI) is being recognized as an effective method to inactivate a broad spectrum of microorganisms, including those resistant to conventional antimicrobials. In the last few years, the development and biological assessment of new photosensitizers for PDI were accompanied by their immobilization in different supports having in mind the extension of the photodynamic principle to new applications, such as the disinfection of blood, water, and surfaces. In this review, we intended to cover a significant amount of recent work considering a diversity of photosensitizers and supports to achieve an effective photoinactivation. Special attention is devoted to the chemistry behind the preparation of the photomaterials by recurring to extensive examples, illustrating the design strategies. Additionally, we highlighted the biological challenges of each formulation expecting that the compiled information could motivate the development of other effective photoactive materials.

The Remarkable Effect of Potassium Iodide in Eosin and Rose Bengal Photodynamic Action against Salmonella Typhimurium and Staphylococcus aureus

“…These ROS can react with biological molecules (e.g., proteins, lipids, and nucleic acids) causing microbial death [16,24,25]. This technique presents several advantages when compared with the use of traditional antimicrobials, showing to be efficient independently of the antimicrobial resistance profile and to prevent further development of resistance even after several cycles of treatment [15][16][17]26]. This approach has been efficient to inactivate several microorganisms, such as gram-negative and gram-positive bacteria [18,19,21], fungi [15,[27][28][29], and viruses [15,30], and to degrade the matrix of microbial biofilms and kill the resident bacteria [16,31,32].…”

The Research on Porphyrins and Analogues in Brazil: A Small Review Covering Catalytic and other Applications since the Beginning at Universidade de São Paulo in Ribeirão Preto until the Joint Venture between Brazilian Researchers and Colleagues from Universidade de Aveiro, Portugal

“…The cytotoxic species are able to cause irreparable damage in different target biomolecules, depending on the intended action (oncological or non-oncological). [262][263][264][265][266] Among the different PSs developed, chlorins exhibit photophysical properties similar to those of porphyrin macrocycles, but with intensified and red-shifted Q bands, making chlorin-containing systems even better candidates for PDT (activation in the near infrared (NIR) region with better light penetration in biological tissues). Interestingly, it was in context of developing compounds for use as photosensitizers that in 2004, the researchers from Aveiro and Ribeirão Preto published one of their first papers, in J. Braz.…”

Evolving Technologies and Strategies for Combating Antibacterial Resistance in the Advent of the Postantibiotic Era

“…The effectiveness of PDT depends on the PS features, the localization of the PS in/around the bacterial cell during light application, irradiation at the appropriate wavelength for PS and the structure of the bacterial cell wall 69. The most commonly used PSs are porphyrins, chlorines and phthalocyanines 40,70. According to a report by Abrahamse and Hamblin, several PS such as HpD (haematoporphyrin derivative), Photofrin, protoporphyrin IX (PPIX), Verteporfin (benzoporphyrin derivative), Radachlorin (now Bremachlorin), fullerenes, Temoporfin, or Foscan (mtetrahydroxyphenylchlorin) have recently received clinical approval 71.…”