Antibacterial Effect of Three Kinds of Methylene Blue Photosensitizers Mediated Photodynamic Therapy on Streptococcus Mutans

Abstract

In order to study the antibacterial effect of methylene blue (MB) photosensitizer-mediated photodynamic therapy (PDT) on Streptococcus mutans in aqueous solvent form, SDS solution form and their mixed form, the influence of MB-PDT on antibacterial effect of Streptococcus mutans in different dosage forms was analyzed. The number of colonies after and before photodynamic therapy mediated by MB-mediated photodynamic therapy was compared by in vitro viable bacterial colony counting method. Negative control group, light alone group, water dosage MB group, mixed dosage MB group, SDS dosage MB group, water dosage MB-PDT group, mixed dosage MB-PDT group and SDS dosage MB-PDT group were set up respectively the effect of different dosage forms of photosensitizers on the antibacterial effect of Streptococcus mutans was analyzed by counting and comparing in vitro for 24 hours. Through in vitro culture experiment, it was found that the number of colonies in water dosage form, mixed dosage form and SDS dosage form MB-PDT group was less than that in water dosage form, mixed dosage form and SDS dosage form MB. The proportion of viable bacteria in SDS MB group was significantly lower than that in water and mixed MB groups, and the antibacterial rate of SDS MB-PDT group was significantly higher than that in water and mixed MB-PDT group. These results indicated that MB-PDT could significantly inhibit the proliferation and growth of Streptococcus mutans. Among them, SDS MB-PDT group had more obvious antibacterial effect on Streptococcus mutans than water MB-PDT group and mixed MB-PDT group, but there was no significant difference in antibacterial effect between water MB-mediated PDT group and mixed MB-mediated PDT group.