The inhibitory effects of polypyrrole on the biofilm formation of Streptococcus mutans

• Published in: PloS one Vol. 14; no. 11; p. e0225584
• Main Authors: Senpuku, Hidenobu, Tuna, Elif Bahar, Nagasawa, Ryo, Nakao, Ryoma, Ohnishi, Makoto
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 27.11.2019; Public Library of Science (PLoS)
• Subjects: Acids; Adult; Albumin; Analysis; Apoptosis; Bacteria; Bacteriology; Biofilms; Biofilms - drug effects; Biofilms - growth & development; Biology and Life Sciences; Bovine serum albumin; Cell surface; Coatings; Composite materials; Dental caries; Dental disorders; Dental materials; Dentistry; Diagnostic reagents industry; Electrochemical analysis; Electrochemistry; Ethics; Extracellular matrix; Humans; Infectious diseases; Laboratory equipment; Medicine and Health Sciences; Methods; Physical Sciences; Polymer industry; Polymers; Polymers - pharmacology; Polypyrroles; Proteins; Protonation; Pyrroles - pharmacology; Saliva; Saliva - microbiology; Serum albumin; Streptococcus infections; Streptococcus mutans; Streptococcus mutans - drug effects; Streptococcus mutans - growth & development; Streptococcus mutans - isolation & purification; Sucrose; Sugar; Teeth; Young Adult; Japan; Istanbul Turkey; Turkey
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0225584

Streptococcus mutans primary thrives on the biofilm formation on the tooth surface in sticky biofilms and under certain conditions can lead to carious lesions on the tooth surface. To search for a new preventive material for oral biofilm-associated diseases, including dental caries, we investigated the effects of polypyrrole, which contains an electrochemical polymer and causes protonation and incorporation of anion under low pH condition, on the biofilm formation of S. mutans and other streptococci. In this study, polypyrrole was applied in biofilm formation assays with the S. mutans strains UA159 and its gtfB and gtfC double mutant (gtfBC mutant), S. sanguinis, S. mitis and S. gordonii on human saliva and bovine serum albumin-coated 96-well microtiter plates in tryptic soy broth supplemented with 0.25% sucrose. The effects of polypyrrole on biofilm formation were quantitatively and qualitatively observed. High concentrations of polypyrrole significantly inhibited the biofilm formation of S. mutans UA159 and S. sanguinis. As an inhibition mechanism, polypyrrole attached to the surface of bacterial cells, increased chains and aggregates, and incorporated proteins involving GTF-I and GTF-SI produced by S. mutans. In contrast, the biofilm formation of gtfBC mutant, S. sanguinis, S. mitis and S. gordonii was temporarily induced by the addition of low polypyrrole concentrations on human saliva-coated plate but not on the uncoated and bovine serum albumin-coated plates. Moreover, biofilm formation depended on live cells and, likewise, specific interaction between cells and binding components in saliva. However, these biofilms were easily removed by increased frequency of water washing. In this regard, the physical and electrochemical properties in polypyrrole worked effectively in the removal of streptococci biofilms. Polypyrrole may have the potential to alter the development of biofilms associated with dental diseases.