Papain gel containing methylene blue for simultaneous caries removal and antimicrobial photoinactivation against Streptococcus mutans biofilms

• Main Authors: Silva, Zenildo Santos (Author), Huang, Ying-Ying (Author), de Freitas, Lucas Freitas (Author), França, Cristiane Miranda (Author), Botta, Sergio Brossi (Author), Ana, Patrícia Aparecida (Author), Mesquita-Ferrari, Raquel Agnelli (Author), Santos Fernandes, Kristianne Porta (Author), Deana, Alessandro (Author), Lima Leal, Cintia Raquel (Author), Prates, Renato Araujo (Author), Bussadori, Sandra Kalil (Author), Hamblin, Michael R (Contributor)
• Other Authors: Harvard University- (Contributor)
• Format: Article
• Language: English
• Published: Nature Publishing Group, 2017-04-05T14:26:33Z.
• Subjects: Article
• Online Access: Get fulltext

This study intended to evaluate the effects of a papain-gel with a red-light absorbing pigment (methylene blue - MB) to mediate photodynamic therapy (PDT) against Streptococcus mutans biofilms. The PapaMBlue was compared with free MB to generate reactive oxygen species using fluorescence probes (SOSG and HPF). PDT (660-nm light) was carried out against S. mutans biofilms grown on either plastic dishes or on collagen membrane and assayed by CFU, live-dead staining using confocal microscopy, transmission electron microscopy and H&E staining for collagen films. Cytotoxicity and subcellular localization was studied in human fibroblasts. Sponges of bioabsorbable type I collagen membrane were exposed to papain based gel, irradiated with laser and analyzed about their integrity by ATR-FTIR. The PapaMBlue produced higher amounts of singlet oxygen and hydroxyl radicals than free MB, possibly due to better disaggregation of the dye in solution. The PapaMBlue antimicrobial effects on biofilms proved to be capable of reducing the S. mutans. Both MTT and PrestoBlue assays showed higher cell viability and metabolism scores in fibroblasts treated with PapaMBlue and MB, possibly due to stimulation of mitochondrial activity and that collagen triple helix is unaffected. The PapaMBlue is equally effective as MB in destroying S. mutans biofilms growing on plastic or collagen without affecting fibroblasts.
National Institutes of Health (U.S.) (Grant R01AI050875)