Effect of Antimicrobial Photodynamic Therapy Using Indocyanine Green Doped with Chitosan Nanoparticles on Biofilm Formation-Related Gene Expression of .

OBJECTIVES

Eradication of (), as an opportunistic periodontopathogen, and inhibition of its virulence factor expression require a new adjunctive therapeutic method. In this study, we accessed the expression level of gene, as a virulence factor associated with biofilm formation, following treatment by antimicrobial photodynamic therapy (aPDT) using indocyanine green (ICG) doped with chitosan nanoparticles (CS-NPs@ICG).

MATERIALS AND METHODS

CS-NPs@ICG was synthesized and examined using scanning electron microscopy (SEM). ATCC 33384 strain was treated with CS-NPs@ICG, as a photosensitizer, which was excited with a diode laser at the wavelength of 810 nm with the energy density of 31.2 J/cm2. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to determine the changes in gene expression level.

RESULTS

Synthetized CS-NPs@ICG was confirmed via SEM. The results revealed that CS-NPs@ICG-mediated aPDT could significantly decrease gene expression to 13.2-fold (P<0.05). There was a remarkable difference between aPDT using CS-NPs@ICG and ICG (P<0.05). The diode laser, ICG, and CS-NPs@ICG were unable to significantly downregulate gene expression (P>0.05).

CONCLUSION

aPDT with CS-NPs@ICG leads to a decrease of the virulence factor of and can be used as an adjunct to routine treatments for successful periodontal therapy in vivo.