Inactivation of Candida albicans Biofilms on Polymethyl Methacrylate and Enhancement of the Drug Susceptibility by Cold Ar/O2 Plasma Jet

Abstract

The antimicrobial effects of the cold plasma for the dental pathogenic microorganism propose a promising approach to the Denture Stomatitis (DS) treatment. However, it is crucial to understand that the complexity of the biofilm microenvironment may compromise the efficiency of the therapy. As one of the major issue for DS, Candida albicans biofilms (ATCC10231) formed on denture base resins were treated by cold Ar/O 2 (2 %) plasma jet. Spatial viability of the biofilms was investigated with confocal scanning laser microscopy through evaluating their inside cross-section properties. Results showed Candida albicans biofilms with thickness of *100 lm was completely inactivated by 8 min plasma treatment. Morphology change of the fungi was also observed by the scanning electron microscopy. Drug susceptibilities, the sessile minimum inhibitory concentration (SMIC50) of the biofilm for amphotericin B and fluconazole were decreased from [32 and [256 lg/mL to 8 and 64 lg/mL after 1 min's plasma treatment, respectively. The reactive species produced from plasma were monitored by optical emission spectroscopy. The successfully inactivation of Candida albicans biofilms and the significant enhancement of its drug susceptibilities induced by the plasma released reactive species propose a promising strategy for the treatment of DS caused by drug-resistant Candida albicans biofilms.

Spectroscopic study of bipolar nanosecond pulse gas-liquid discharge in atmospheric argon

“…Room temperature non-thermal plasma generated by gasliquid discharge attracted considerable attention for diversified applications in the areas of microorganism inactivation [1,2], medical technology [3,4] and water purification [5]. For gas-liquid discharge, discharges that occur above the liquid surface or at the gas-liquid interface can initiate various physiochemical reactions and generate abundant active species.…”

Non-Thermal O2 Plasma Efficacy on C. albicans and Its Effect on Denture Base Resin Color

“…They evaluated atmospheric plasma using argon (Ar) or Ar/O 2 mixture as working gas. Matthes et al [52] obtained a 4.12-log reduction of C. albicans viability over 10 min using a dielectric barrier discharge whereas Wang et al [53] reached a 6-log reduction over 8 min using a plasma jet. These results vary due to the different plasma sources and the different methodologies used for evaluation.…”

“…Hence, plasma processes have been tested for one decade on resin for denture base. Some studies dealt with the effect of atmospheric plasma on C. albicans biofilms developed on PMMA [52,53]. They evaluated atmospheric plasma using argon (Ar) or Ar/O 2 mixture as working gas.…”

Incorporation of antimicrobial agents in denture base resin: A systematic review

“…However, the formation of C. albicans dominated biofilms and other pathogens leading to CADS on PMMA DBRs is of concern. 4,49 Investigations have attempted to reduce biofilm formation by incorporating various materials into PMMA. 8 The following organic compounds identified in the systematic review as potential antimicrobial agents will be explored in relation to their ability to be used with dental materials.…”

“…Acrylic polymers such as polymethyl methacrylate (PMMA) are the most frequently used materials in the fabrication of removable dental prostheses and have been clinically accepted for over 70 years because of their physical, mechanical, and esthetic properties, as well as low cost, straightforward fabrication, and biocompatibility. [1][2][3][4][5] Interconnected factors such as saliva, levels of acidity (pH), oral microorganisms, 6 and the type of oral prosthesis can generate conditions that may impair natural saliva flow, exert mechanical compression, increase temperature, and decrease light to mucosal tissues. 7 These conditions may influence the accumulation of a denture biofilm and promote cariogenic or periodontal biofilms.…”