Antibiofilm Effect of D-enantiomeric Peptide Alone and Combined with EDTA In Vitro

Dan Wang, Ya Shen, Jingzhi Ma, Robert Hancock, Markus Haapasalo

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7 Citations (Scopus)


Introduction The aim of this study was to evaluate the effect of DJK-5, a newly developed cationic antimicrobial peptide, on oral multispecies and Enterococcus faecalis biofilms alone or combined with the endodontic chelating agent EDTA in vitro. Methods Oral multispecies biofilms from 2 donors and E. faecalis VP3-181 biofilm were grown on collagen-coated hydroxyapatite disks. After incubation for 3 days or 3 weeks, the biofilms were exposed to sterile saline (negative control), 8.5% EDTA, 2% chlorhexidine digluconate (CHX), 5 μg/mL DJK-5, 10 μg/mL DJK-5, a mixture of 5 μg/mL DJK-5 and 8.5% EDTA (final concentration), or a mixture of 10 μg/mL DJK-5 and 8.5% EDTA, all for 1 and 3 minutes. The proportions of dead bacteria in the biofilms were assessed by the LIVE/DEAD staining (Thermo Fisher Scientific, Waltham, MA) and confocal microscopy. Results The peptide DJK-5 rapidly killed most bacteria in all biofilms, with significant differences to the control, 8.5% EDTA and 2% CHX (P <.01). Basically, a higher DJK-5 concentration and longer exposure (3 minutes) were more effective than a low concentration and short time exposure (P <.05). There were no significant differences in antibiofilm activities between DJK-5 used alone or in the mixture with 8.5% EDTA at either concentration. EDTA (8.5%) had no significant antimicrobial effect compared with the negative control (P >.05), but, unlike DJK-5 alone, the mixture retained the ability to remove smear layers. In peptide groups, there were no significant differences in dead bacteria proportions between 3-day and 3-week biofilms, except for 10 μg/mL DJK-5 used alone for 3 minutes on the multispecies biofilms. Conclusions DJK-5 exerted antibiofilm ability on E. faecalis and oral multispecies biofilms grown on hydroxyapatite disks, both alone and when combined with 8.5% EDTA.

Original languageEnglish
Pages (from-to)1862-1867
Number of pages6
JournalJournal of Endodontics
Issue number11
Publication statusPublished - 1 Nov 2017
Externally publishedYes


  • Biofilm
  • DJK-5
  • EDTA
  • confocal laser scanning microscopy

ASJC Scopus subject areas

  • Dentistry(all)

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