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Antimicrobial Effect of the Amniotic Membrane Isolated and Associated with Photodynamic Therapy
Amanda Cerquearo Rodrigues Dos Santos1, Guilherme Rodrigues Teodoro1, Juliana Ferreira-Strixino2
1Center for Studies and Microbiological Analysis (CEAM)-Golden Technology, Av. Shishima Hifumi, São José dos Campos 2911, SP, Brazil.
Abstract:
Microbial control through alternative therapies, such as the amniotic membrane (AM) and antimicrobial photodynamic therapy (aPDT), has been gaining prominence with the advancement of bacterial resistance to conventional treatments. This study aimed to evaluate the antimicrobial effect of AM isolated and associated with aPDT using the PHTALOX® as a photosensitizer (PS) against Staphylococcus aureus and Pseudomonas aeruginosa biofilms. The groups studied were: C+; L; AM; AM+L; AM+PHTX; and AM+aPDT. The irradiation parameters were 660 nm, 50 J.cm-2, and 30 mW.cm-2. Two independent microbiological experiments were carried out in triplicate, and the results were analyzed by CFU/mL counting and a metabolic activity test, both statistically analyzed (p < 0.05). The integrity of the AM was verified after the treatments by a scanning electron microscope (SEM). The groups AM, AM+PHTX, and, mainly, AM+aPDT showed a statistical difference when compared to C+ regarding the decrease in CFU/mL and metabolic activity. SEM analysis showed significant morphological alterations in the AM+PHTX and AM+aPDT groups. The treatments with AM isolated or associated with PHTALOX® were adequate. The association had potentiated the biofilm effect, and the morphological differences presented by AM after treatment did not hinder its antimicrobial effect, encouraging its use in biofilm formation locals.
Insights
Amniotic membrane (AM) combined with antimicrobial photodynamic therapy (aPDT) effectively combats bacterial biofilms. This innovative approach shows promise against antibiotic-resistant microbes.
Area of Science:
- Biomedical Engineering
- Microbiology
- Photomedicine
Background:
- Rising bacterial resistance necessitates alternative antimicrobial strategies.
- Amniotic membrane (AM) and antimicrobial photodynamic therapy (aPDT) are promising alternative therapies.
- Biofilm infections pose a significant clinical challenge due to their recalcitrance.
Purpose of the Study:
- To assess the antimicrobial efficacy of AM alone and in combination with aPDT.
- To evaluate the impact on Staphylococcus aureus and Pseudomonas aeruginosa biofilms.
- To investigate the role of PHTALOX® as a photosensitizer in AM-based therapy.
Main Methods:
- Experimental groups included controls, AM, PHTALOX® (PHTX), and AM combined with light (L) or aPDT.
- Microbiological assays (CFU/mL, metabolic activity) were performed in triplicate.
- Scanning electron microscopy (SEM) assessed AM integrity post-treatment.
Main Results:
- AM and AM+aPDT significantly reduced bacterial load and metabolic activity compared to controls.
- The combination of AM with PHTALOX® and light (AM+aPDT) demonstrated the most potent antimicrobial effect.
- SEM revealed morphological changes in AM post-treatment, but these did not impair antimicrobial function.
Conclusions:
- AM, alone or with PHTALOX®, is effective against bacterial biofilms.
- Combining AM with aPDT potentiates antimicrobial activity.
- AM-based therapies are viable for treating biofilm infections, even with post-treatment morphological alterations.
