Biofilm of oral pathogenic microorganisms induced by their multiplication and coaggregation would lead to periodontitis. In biofilms, the extracellular polymeric substances (EPS) as a protective shield encapsulates the individual bacteria, protecting them against attack. To alleviate periodontal disease, disrupting the EPS of pathogenic bacteria is crucial and challenging. Based on the sufficient capacity of disorganizing EPS of our designed cationic dextrans, we hypothesized that these polymers could be competent in relieving periodontitis. We validated that cationic dextrans could induce the phase transition of EPS in biofilms, especially the Porphyromonas gingivalis (P. gingivalis), a keystone periodontal pathogen, thus effectively destroying biofilm in vitro. More importantly, satisfactory in vivo treatment was achieved in a rat periodontal disease model. In summary, the study exploited a practical and effective strategy to treat periodontitis with cationic dextrans’ powerful biofilm-controlling potential.

Statement of significance

Periodontal disease is closely related to dental plaque biofilms on the tooth surface. The biofilm forms gel structures and shields the bacteria underneath, thus protecting oral pathogens from traditional anti-bacterial reagents. Due to limited penetration into gel, the efficacy of these reagents in biofilm elimination is restricted. Our designed cationic dextran could wipe out the coverage of gel-like EPS to disperse encapsulated bacteria. Such superior capacity endowed them with satisfactory effect in disrupting biofilm. Notably, in a rat periodontitis model, cationic dextrans dramatically suppressed alveolar bone loss and alleviated periodontal inflammation by controlling dental plaque. Given the increasing global concerns about periodontal disease, it's worth expanding the application of cationic dextrans both scientifically and clinically.