1 research outputs found
Targeting Cariogenic Streptococcus mutans in Oral Biofilms with Charge-Switching Smart Antimicrobial Polymers
Cariogenic
biofilms produce strong acidic microenvironments, which
is the primary cause of dental caries. Streptococcus
mutans is a dominant species in cariogenic biofilms.
Herein, we report a pH-responsive, charge-switching smart copolymer
to selectively target and eradicate bacteria in cariogenic biofilms.
To that end, the copolymer is designed to be activated in an acidic
environment. The smart copolymer, Poly-1A, consists of ternary compositions
of monomers with a cationic ethyl ammonium group, a carboxylic group,
and a hydrophobic group in the side chains. The net charge of Poly-1A
was charge neutral at neutral pH, but it switched to be cationic because
the acidic carboxylate side chains were protonated and became neutral;
however, the ammonium groups remained positive. Poly-1A with a net
positive charge bound to the anionic surface of oral bacteria by electrostatic
interactions and disrupted the bacterial membranes, causing bacterial
death. Poly-1A reduced the cell viability of planktonic and biofilm S. mutans at pH 4.5, while it was not bactericidal
at pH 7.4. Poly-1A did not reduce the cell viability of human gingival
fibroblasts and periodontal ligament stem cells for a 1 h incubation