Nanoparticle-encapsulated chlorhexidine against oral bacterial biofilms

PLoS One. 2014 Aug 29;9(8):e103234. doi: 10.1371/journal.pone.0103234. eCollection 2014.


Background: Chlorhexidine (CHX) is a widely used antimicrobial agent in dentistry. Herein, we report the synthesis of a novel mesoporous silica nanoparticle-encapsulated pure CHX (Nano-CHX), and its mechanical profile and antimicrobial properties against oral biofilms.

Methodology/principal findings: The release of CHX from the Nano-CHX was characterized by UV/visible absorption spectroscopy. The antimicrobial properties of Nano-CHX were evaluated in both planktonic and biofilm modes of representative oral pathogenic bacteria. The Nano-CHX demonstrated potent antibacterial effects on planktonic bacteria and mono-species biofilms at the concentrations of 50-200 µg/mL against Streptococcus mutans, Streptococcus sobrinus, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans and Enterococccus faecalis. Moreover, Nano-CHX effectively suppressed multi-species biofilms such as S. mutans, F. nucleatum, A. actinomycetemcomitans and Porphyromonas gingivalis up to 72 h.

Conclusions/significance: This pioneering study demonstrates the potent antibacterial effects of the Nano-CHX on oral biofilms, and it may be developed as a novel and promising anti-biofilm agent for clinical use.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aggregatibacter actinomycetemcomitans / drug effects
  • Aggregatibacter actinomycetemcomitans / physiology
  • Anti-Bacterial Agents / administration & dosage
  • Anti-Bacterial Agents / pharmacology
  • Anti-Infective Agents, Local / administration & dosage*
  • Anti-Infective Agents, Local / pharmacology
  • Bacteria / drug effects
  • Bacterial Infections / drug therapy
  • Bacterial Physiological Phenomena / drug effects*
  • Biofilms / drug effects*
  • Chlorhexidine / administration & dosage*
  • Chlorhexidine / pharmacology
  • Dental Plaque / drug therapy
  • Dental Plaque / microbiology
  • Drug Carriers / chemistry*
  • Fusobacterium nucleatum / drug effects
  • Fusobacterium nucleatum / physiology
  • Humans
  • Mouth / microbiology*
  • Nanoparticles / chemistry*
  • Nanoparticles / ultrastructure
  • Porphyromonas gingivalis / drug effects
  • Porphyromonas gingivalis / physiology
  • Streptococcus mutans / drug effects
  • Streptococcus mutans / physiology


  • Anti-Bacterial Agents
  • Anti-Infective Agents, Local
  • Drug Carriers
  • Chlorhexidine

Grant support

This study has been supported by the General Research Fund (GRF) from the Hong Kong Research Grants Council (HKU767512M and 768713M) and the Modern Dental Laboratory/HKU Endowment Fund to LJJ. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.