Methylene blue mediated antimicrobial photodynamic therapy in clinical human studies: The state of the art
Rebeca Boltes Cecatto1, Laís Siqueira de Magalhães2, Maria Fernanda Setúbal Destro Rodrigues3
1School of Medicine of Universidade Nove de Julho/UNINOVE, Sao Paulo, 01504-001, Brazil; Rehabilitation Service of the Instituto do Câncer do Estado de Sao Paulo School of Medicine of the University of Sao Paulo, Sao Paulo, 01246-903, Brazil.
Background:
The goal of this study was to update the information about aPDT when using methylene blue (MB) for the treatment of human clinical infections of different etiologies, except for dentistry applications, and to also investigate the best parameters of MB to achieve this.
Methods:
This study was a systematic literature review performed according to the PRISMA guidelines. A literature search was performed for studies with adult human patients (>18 years-old) published in the English, French, Spanish, Portuguese, and Italian languages when using the electronic databases of MEDLINE, Embase, OpenGrey, and LILACS.
Results:
1260 relevant articles were found. After a reading of the titles and the abstracts, only 85 articles were selected for a complete reading. After the complete reading, only 05 studies were selected for data extraction, where the treatments were onychomycosis, oral candidiasis, and infectious diabetic foot ulcers. As for the MB concentrations, 0.0003 to 0.06 molar were used. Pre-irradiation times ranged from 1 to 5 min, while the irradiation times ranged from 8 s to 10 min. As for the light sources, lasers, LED, and lamps were used, with irradiances ranging from 50 to 750 mW/cm2 and radiant exposures from 6 to 18 J/cm2.
Conclusions:
For the field of clinical applications of aPDT to develop, studies with a higher level of evidence are needed. For example, future reports should aim at comparing aPDT directly with standard techniques and a placebo aPDT, together with larger samples, and with more objective clinical evaluation methods, in order to provide useful data for the clinically relevant aPDT protocols.
Insights
This study reviewed antimicrobial photodynamic therapy (aPDT) using methylene blue (MB) for human infections. Higher evidence studies are needed to optimize MB parameters for clinical use.
Area of Science:
- Photomedicine
- Antimicrobial Therapy
- Biochemistry
Background:
- Antimicrobial photodynamic therapy (aPDT) shows promise for treating various human infections.
- Methylene blue (MB) is a photosensitizer used in aPDT, but optimal parameters require further investigation.
- Excludes dental applications, focusing on broader clinical infections.
Purpose of the Study:
- To update information on aPDT using MB for human clinical infections.
- To identify optimal MB parameters for effective aPDT protocols.
- To review current evidence and identify research gaps.
Main Methods:
- Systematic literature review following PRISMA guidelines.
- Searched MEDLINE, Embase, OpenGrey, LILACS for English, French, Spanish, Portuguese, Italian studies.
- Included adult human patients (>18 years) with various infections.
Main Results:
- Identified 5 studies for data extraction from 1260 initial articles.
- Treatments included onychomycosis, oral candidiasis, and diabetic foot ulcers.
- MB concentrations ranged from 0.0003–0.06 M; irradiation parameters varied.
Conclusions:
- Higher level of evidence studies are crucial for advancing clinical aPDT.
- Future research should compare aPDT with standard treatments and placebo.
- Larger sample sizes and objective evaluation methods are needed for robust clinical protocols.
