The Effect of Antimicrobial Photodynamic Therapy Using Chlorophyllin–Phycocyanin Mixture on <i>Enterococcus faecalis</i>: The Influence of Different Light Sources

• Main Authors: Nasim Chiniforush, Maryam Pourhajibagher, Steven Parker, Stefano Benedicenti, Abbas Bahador, Tudor Sălăgean, Ioana Roxana Bordea
• Format: Article
• Language: English
• Published: MDPI AG 2020-06-01
• Series: Applied Sciences
• Subjects: chlorophyllin–phycocyanin mixture; diode laser; LED; <i>Enterococcus faecalis</i>; cell cytotoxicity
• Online Access: https://www.mdpi.com/2076-3417/10/12/4290

The purpose of this study was to evaluate the in vitro effect of the chlorophyllin–phycocyanin mixture (Photoactive+) as a photosensitizer (PS) during antimicrobial photodynamic therapy (aPDT) on the count of <i>Enterococcus faecalis</i> (<i>E. faecalis</i>) using different light sources. The antimicrobial effect of aPDT with chlorophyllin–phycocyanin mixture using different light sources including diode laser (λ = 660 nm), diode laser (λ = 635 nm), LED (λ = 450 ± 30 nm) alone or in combination was assessed using microbial cell viability assay against <i>E. faecalis</i>. In addition, the cell cytotoxicity of Photoactive+ was assessed on human gingival fibroblast (HuGu) cells by MTT assay; <i>E</i>. <i>faecalis</i> growth when treated by both red wavelengths (635 nm, 660 nm) and combination of LED (420–480 nm) and red wavelengths (635 nm, 660 nm), significantly reduced compared to the control group (<i>p</i> < 0.05). There was no significant reduction in the number of viable cells exposed to Photoactive+ compared to the control group (<i>p</i> < 0.05). This study shows that the application of chlorophyllin–phycocyanin mixture and irradiation with emission of red light achieved a better result for bacterial count reduction, compared to a control. This component can be applied safely due to very negligible cytotoxicity.