Antibacterial Photodynamic Therapy Using Zinc Phthalocyanine Against Multidrug-resistant Pseudomonas aeruginosa in
Kiyani Forouhe1, Ghandehari Fereshte1, Fatemi Mahnoosh2
1Department of Microbiology, Fal.C., Islamic Azad University, Falavarjan, Iran.
Introduction:
Due to the prevalence of MDR strains, alternative treatments such as antimicrobial photodynamic therapy (aPDT) have received much attention. This technique is an innovative technology that utilizes photosensitizers and generates active oxygen species. This study aimed to investigate the effectiveness of aPDT against multidrug-resistant (MDR) Pseudomonas aeruginosa using a nanoemulsion containing zinc phthalocyanine (NE/ZnPc) in a burn wound model under both in in vitro and in vivo conditions.
Materials & Methods:
Optimization of PDT conditions -across different drug concentrations, different incubation times, different doses of laser radiation -was performed in vitro, and then the anti-biofilm effects of the optimal concentration against clinical isolates of MDR P. aeruginosa were investigated. Under in vivo conditions, male rats were divided into seven groups: Control, burn wound group, bacterial-infected burn wound, infected burn wound with laser treatment, infected wound treated with laser and drug (optimal concentration), infected wound treated with drug alone, and infected wound treated with nanoemulsion alone. The area of the burn wound was measured at the beginning and end of the experiment. Pieces of skin tissue were collected to perform histological studies and measure the expression of EGFR and SOD1 genes.
Results:
Based on the results, the drug at a concentration of 40 µg/mL encapsulated in nanoemulsion, a laser dose of 13 J/cm2, and the incubation time of 2 hours were selected as optimal conditions. Under these conditions, 80% biofilm inhibition was observed. According to the histological results, NE/ZnPc-mediated aPDT and laser radiation reduced the burn wound area, significantly accelerated the wound healing process, increased EGFR gene expression, and decreased SOD1 gene expression to normal levels.
Conclusion:
The promising antibacterial and anti-biofilm activity of NE/ClZnlPc-mediated aPDT against MDR P. aeruginosa, along with the increased expression of EGFR and SOD1 levels in infected rat wounds, indicate that this treatment may be served as an alternative approach to eradicate MDR bacteria.
