Applications of Antimicrobial Photodynamic Therapy against Bacterial Biofilms

Abstract

Antimicrobial photodynamic therapy and allied photodynamic antimicrobial chemotherapy have shown remarkable activity against bacterial pathogens in both planktonic and biofilm forms. There has been little or no resistance development against antimicrobial photodynamic therapy. Furthermore, recent developments in therapies that involve antimicrobial photodynamic therapy in combination with photothermal hyperthermia therapy, magnetic hyperthermia therapy, antibiotic chemotherapy and cold atmospheric pressure plasma therapy have shown additive and synergistic enhancement of its efficacy. This paper reviews applications of antimicrobial photodynamic therapy and non-invasive combination therapies often used with it, including sonodynamic therapy and nanozyme enhanced photodynamic therapy. The antimicrobial and antibiofilm mechanisms are discussed. This review proposes that these technologies have a great potential to overcome the bacterial resistance associated with bacterial biofilm formation.

Recent developments of sonodynamic therapy in antibacterial application

“…3,4 Furthermore, bacteria in biofilms could enhance bacterial virulence through population-sensing molecular interactions. 5 In 2019, a report from the United Nations stated that drug-resistant bacterial infections killed at least 700 000 people globally each year. Without specific methods to curb drug-resistant bacterial infections, the number of deaths causing by bacterial infections will exceed those caused by cancer, reaching 10 000 000 in 2050.…”

Nanozyme: A new Approach for Anti-microbial Infections

“…As a material with catalytic activity and good modifiable properties, the nanozymes coupled with photosensitizers can endow them with photodynamic properties that lead to photosensitization of oxygen to produce ROS, enhancing their catalytic activity and achieving the killing effect on microorganisms [46] . The shortcomings of nanozymes for anti-infection therapy mainly stem from their inadequate production of lethal ROS, both in terms of their yield and the time they can be sustained released.…”

Porphyrins and Metalloporphyrins Combined with N-Heterocyclic Carbene (NHC) Gold(I) Complexes for Photodynamic Therapy Application: What Is the Weight of the Heavy Atom Effect?

“…Photodynamic therapy (PDT) is a clinical therapeutic modality with considerable potential for application in a wide range of diseases, such as cancer [1] as well as the antimicrobial and environmental fields [2][3][4][5][6][7]. A PDT protocol involves the combination of three key components: light, with an appropriate wavelength, molecular oxygen, and a photosensitizer, a molecule which can produce reactive oxygen species (ROS) that are deadly to cells when excited by light of a proper wavelength in presence of oxygen.…”